dotnet faqs1

8/13/2019 dotnet faqs1

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(B)What is IL?

Twist :- What is MSIL or CIL , What is JIT?

(IL)Intermediate Language is also nown as MSIL (Mi!roso"t Intermediate Language) or CIL

(Common Intermediate Language)# $ll #%&T sour!e !ode is !om'iled to IL# This IL is then

!onerted to ma!hine !ode at the 'oint where the so"tware is installed, or at run-time * a Just-

In-

Time (JIT) !om'iler#

(B)What is the CL+?

ull "orm o" CL+ is Common Language +untime and it "orms the heart o" the #%&T

"ramewor#$ll Languages hae runtime and its the res'onsiilit* o" the runtime to tae !are o"

the !ode ee!ution o" the 'rogram#or eam'le .C// has MSC+T01#2LL,.B3 has

MS.B.M31#2LL , Jaa has Jaa .irtual Ma!hine et!# Similarl* #%&T has CL+#ollowing are the

res'onsiilities o" CL+

4 5arage Colle!tion :- CL+ automati!all* manages memor* thus eliminating

memor* leaes# When o6e!ts are not re"erred 5C automati!all* releases those

memor* thus 'roiding e""i!ient memor* management#

4 Code $!!ess Se!urit* :- C$S grants rights to 'rogram de'ending on the se!urit*

!on"iguration o" the ma!hine#&am'le the 'rogram has rights to edit or !reate

a new "ile ut the se!urit* !on"iguration o" ma!hine does not allow the 'rogramto delete a "ile#C$S will tae !are that the !ode runs under the enironment o"

ma!hines se!urit* !on"iguration#

4 Code .eri"i!ation :- This ensures 'ro'er !ode ee!ution and t*'e sa"et* while

the !ode runs#It 'reents the sour!e !ode to 'er"orm illegal o'eration su!h as

a!!essing inalid memor* lo!ations et!#

4 IL( Intermediate language )-to-natie translators and o'timi7er8s :- CL+ uses

JIT and !om'iles the IL !ode to ma!hine !ode and then ee!utes# CL+ also

determines de'ending on 'lat"orm what is o'timi7ed wa* o" running the IL

!ode#

(B)What is the CTS?

In order that two language !ommuni!ate smoothl* CL+ has CTS (Common T*'eS*stem)#&am'le

in .B *ou hae 9Integer and in C// *ou hae 9long these datat*'es are not !om'atile so the

inter"a!ing etween them is er* !om'li!ated# In order that two di""erent languages !an

!ommuni!ate

;


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(B)What is Managed Code?

Managed !ode runs inside the enironment o" CL+ i#e# #%&T runtime#In short all IL are managed

!ode#But i" *ou are using some third 'art* so"tware eam'le .B3 or .C// !om'onent the* are

unmanaged !ode as #%&T runtime (CL+) does not hae !ontrol oer the sour!e !ode ee!ution

o" the language#

(B)What is $sseml* ?

4 $sseml* is unit o" de'lo*ment lie && or a 2LL#

4 $n asseml* !onsists o" one or more "iles (dlls, ee8s, html "iles et!#), and

re'resents a grou' o" resour!es, t*'e de"initions, and im'lementations o" those

t*'es# $n asseml* ma* also !ontain re"eren!es to other assemlies# These

resour!es, t*'es and re"eren!es are des!ried in a lo! o" data !alled a mani"est#

The mani"est is 'art o" the asseml*, thus maing the asseml* sel"-des!riing#

4 $n asseml* is !om'letel* sel"-des!riing#$n asseml* !ontains metadata

in"ormation, whi!h is used * the CL+ "or eer*thing "rom t*'e !he!ing and

se!urit* to a!tuall* inoing the !om'onents methods#$s all in"ormation is in

asseml* itsel" it is inde'endent o" registr*#This is the asi! adantage as

!om'ared to C


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4 %ames'a!e !an s'an multi'le asseml*#

($)I" *ou want to iew a $sseml* how to *ou go aout it ?

Twist : What is IL2$SM ?

When it !omes to understanding o" internals nothing !an eat IL2$SM#IL2$SM asi!all*

!onerts

the whole ee or dll in to IL !ode#To run IL2$SM *ou hae to go to HC:Erogram ilesMi!roso"t

;Is *our e'erien!e "ull* in #%&T , or do *ou hae an* 'rior e'erien!e in other

mi!roso"t te!hnolog* lie .B3,.C// et!

;Can *ou gie me two re"eren!es o" *our 'reious !om'an* whom i !an !onta!t ?

1

.isual Studio #%&T 11AS2>#>BinH# %ote that i had >#> *ou hae to 'roal* !hange it

de'ending on the t*'e o" "ramewor ersion *ou hae#

I" *ou run I2$SM#&& "rom the 'ath *ou will e 'o''ed with the I2$SM ee 'rogram as

shown in "igure IL2$SM#Cli! on "ile and rowse to the res'e!tie dire!tor* "or the 2LL whose

asseml* *ou want to iew#$"ter *ou sele!t the 2LL *ou will e 'o''ed with a tree iew details

o" the 2LL as shown in "igure IL2$SM## Mani"est .iew

($) What is Mani"est?

$sseml* metadata is stored in Mani"est#Mani"est !ontains all the metadata needed to do the

"ollowing things( See igure Mani"est .iew "or more details) :

4 .ersion o" asseml*

4 Se!urit* identit*

4 S!o'e o" the asseml*

4 resole re"eren!es to resour!es and !lasses#

4 The asseml* mani"est !an e stored in either a E& "ile (an #ee or #dll) with

Mi!roso"t intermediate language (MSIL) !ode or in a stand-alone E& "ile that

!ontains onl* asseml* mani"est in"ormation#

; ae *ou heard aout our !om'an* ? Sa* "ie 'oints aout our !om'an* ? Just read atleast

on!e what !om'an* *ou are going "or ?

; Whi!h is the est 'ro6e!t *ou hae done till now ? and in what sense the 'ro6e!t was the est ?


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A

(B)Where is ersion in"ormation stored o" a asseml* ?

.ersion in"ormation is stored in asseml* in mani"est#

(I)Is ersioning a''li!ale to 'riate assemlies?

.ersioning !on!e't is onl* a''li!ale to gloal asseml* !a!he (5$C) as 'riate asseml* lie in

there indiidual "olders#

(B) What is 5$C ?

Twist :- What are situations when *ou register #%&T asseml* in 5$C ?

5$C (5loal $sseml* Ca!he) is where shared #%&T asseml* reside#5$C is used in the "ollowing

situations :-

4 I" the a''li!ation has to e shared among seeral a''li!ation#

4 I" the asseml* has some s'e!ial se!urit* re=uirements lie onl* administrators

!an remoe the asseml*#I" the asseml* is 'riate then a sim'le delete o"

asseml* the asseml* "ile will remoe the asseml*#

%ote :- +egistering #%&T asseml* in 5$C !an lead to the old 'rolem o" 2LL hell#

Where C


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igure:- ># Cli! on 'ro6e!t and then !li! on 9!lasslirar*> 'ro'erties menu to sign the

asseml*

4 Cli! on 'ro6e!t -- 'ro'erties and the rowse the S% "ile to the res'e!tie

"older and !om'ile the 'ro6e!t#

;Whi!h is *our "aorite .B3 or .B#%&T#####Just do not get in to arguments ?

; What8s *our "aorite .B#%&T or CN####Ere'are a di'lomati! answer#### 2o not get in to

arguments#

igure :- >#@ Cli! on Gse a e* "ile to sign the asseml* with strong name

(I)ow to add and remoe a asseml* "rom 5$C?

There are two wa*s to install #%&T asseml* in 5$C:-

4 Gsing Mi!roso"t Installer Ea!age#Kou !an get download o" installer "rom

htt':OOwww#mi!roso"t#!om#

4 Gsing 5a!util# 5oto 9.isual Studio Command Erom't and t*'e 9ga!util Pi

(asseml*Qname)#Where (asseml*Qname) is the 2LL name o" the 'ro6e!t#

; I" *ou "ail in one interiew does not mean *ou hae to disa''ointed#ee' tr*ing IT

industr* has lot in store#

; $s a interiewer alwa*s rememer that *ou will also e sitting sometimes at the other end#So

do not as an* 's*!he=uestion whi!h does not 6udge an*thing o" a !andidate#

@

(B) What is 2ela* signing ?

2uring deelo'ment 'ro!ess *ou will need strong name e*s to e e'osed to deelo'er whi!h

will is not a good 'ra!ti!e "rom se!urit* as'e!t 'oint o" iew#In su!h situations *ou !an assign the

e* later on and during deelo'ment *ou an use dela* signing

ollowing is 'ro!ess to dela* sign a asseml*:

4 irst otain *our string name e*s using S%#&

4 $nnotate the sour!e !ode "or the asseml* with two !ustom attriutes "rom

S*stem#+e"le!tion: $sseml*e*ile$ttriute, whi!h 'asses the name o" the "ile

!ontaining the 'uli! e* as a 'arameter to its !onstru!tor# $sseml*2ela*Sign$ttriute,whi!h indi!ates that dela* signing is eing used * 'assing true as a 'arameter to its

!onstru!tor# or eam'le as shown elow:

R.isual Basi!

$sseml*:$sseml*e*ile$ttriute(Hm*e*#snH)U

$sseml*:$sseml*2ela*Sign$ttriute(true)U

RCN

Rasseml*:$sseml*e*ile$ttriute(Hm*e*#snH)

Rasseml*:$sseml*2ela*Sign$ttriute(true)

The !om'iler inserts the 'uli! e* into the asseml* mani"est and reseres s'a!e in the E& "ile

"or

the "ull strong name signature# The real 'uli! e* must e stored while the asseml* is uilt so

that other assemlies that re"eren!e this asseml* !an otain the e* to store in their own

asseml*

re"eren!e#

4 Be!ause the asseml* does not hae a alid strong name signature, the eri"i!ation o"

that signature must e turned o""# Kou !an do this * using the P.r o'tion with the

Strong %ame tool#The "ollowing eam'le turns o"" eri"i!ation "or an asseml* !alled

m*$sseml*#dll#

Sn P.r m*$sseml*#dll

D


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4 Just e"ore shi''ing, *ou sumit the asseml* to *our organi7ationFs signing authorit*

"or the a!tual strong name signing using the P+ o'tion with the Strong %ame tool#The

"ollowing eam'le signs an asseml* !alled m*$sseml*#dll with a strong name using

the sge*#sn e* 'air#

Sn -+ m*$sseml*#dll sge*#sn

(B)What is garage !olle!tion?

5arage !olle!tion

5arage !olle!tion is a CL+ "eature whi!h automati!all* manages memor*# Erogrammers "orget

to release the o6e!ts while !oding ##### la7iness ( +ememer in .B3 where one o" the good

'ra!ti!es is to set o6e!t to nothing)#CL+ automati!all* releases o6e!ts when the* are no longer

re"eren!ed and in use#CL+ runs on non-deterministi! to see the unused o6e!ts and !leans them#

minutes he was roaming around


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the same =uestion in order to get answer "rom me (re=uirement was "or a sim'le dataase

'ro6e!t)# Beware o" su!h !om'anies and interiewers *ou an land u' no where#

JIT !om'iler is a 'art o" the runtime ee!ution enironment#

In Mi!roso"t #%&T there are three t*'es o" JIT !om'ilers:

A>

4 Ere-JIT# Ere-JIT !om'iles !om'lete sour!e !ode into natie !ode in a single !om'ilation

!*!le# This is done at the time o" de'lo*ment o" the a''li!ation#

4 &!ono-JIT# &!ono-JIT !om'iles onl* those methods that are !alled at runtime#

oweer, these !om'iled methods are remoed when the* are not re=uired#

4 %ormal-JIT# %ormal-JIT !om'iles onl* those methods that are !alled at runtime#

These methods are !om'iled the "irst time the* are !alled, and then the* are stored in

!a!he# When the same methods are !alled again, the !om'iled !ode "rom !a!he is

used "or ee!ution#

(B) What are .alue t*'es and +e"eren!e t*'es ?

.alue t*'es dire!tl* !ontain their data are either allo!ated on the sta! or allo!ated in-line in a

stru!ture#

+e"eren!e t*'es store a re"eren!e to the alueFs memor* address, and are allo!ated on the hea'#

+e"eren!e t*'es !an e sel"-des!riing t*'es, 'ointer t*'es, or inter"a!e t*'es#

.ariales that are alue t*'es ea!h hae their own !o'* o" the data, and there"ore o'erations onone ariale do not a""e!t other ariales# .ariales that are re"eren!e t*'es !an re"er to the

same

o6e!t there"ore, o'erations on one ariale !an a""e!t the same o6e!t re"erred to * another

ariale#$ll t*'es derie "rom the S*stem#


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4 as the WIT !onstru!t whi!h is not in CN#

4 The .B#%&T 'art o" .isual Studio #%&T !om'iles *our !ode in the a!ground#

While this is !onsidered an adantage "or small 'ro6e!ts, 'eo'le !reating er* large

'ro6e!ts hae "ound that the I2& slows down !onsideral* as the 'ro6e!t gets larger#

$dantages o" CN

4 ML do!umentation is generated "rom sour!e !ode ut this is now een in!or'orated

in Whide*#

4 #D &!e'tion ierar!h*

%ote:- ranl* I hae alwa*s relied on using Mi!roso"t e!e'tion a''li!ation lo!s# $s

su!h I hae neer used a''li!ation e!e'tion I thin most o" the wor is done using S*steme!e'tion !lasses#

(I)What is C


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4 $dding re"eren!e in .isual Studio#net#See "igure elow ($dding re"eren!e using .S#%&T

11)#Wra''er !lass is generated and 'la!ed in the 9BI% dire!tor*#

igure :- #> $dding +e"eren!e using .S#%&T 11

##%&T Intero'erailit*

A3

4 Gsing T*'e lirar* im'ort tool# Tlim'#ee *ourname#dll#

4 Gsing intero'seri!es#S*stem#runtime#Intero'seri!es names'a!e !ontains !lass

T*'eLi Conerter whi!h 'roides methods to !onert C


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&nd 5et

Set(B*.al alue $s String)

EstrCustomerCode V alue

&nd Set

&nd Ero'ert*

Euli! Ero'ert* Customer%ame() $s String Im'lements

ICustomer#Customer%ame

5et

+eturn EstrCustomer%ame

&nd 5et

Set(B*.al alue $s String)

EstrCustomer%ame V alue

&nd Set

&nd Ero'ert*

Euli! Su %ew()

&nd Su&nd Class

%ote :- Sour!e !ode o" this is 'roided in C2 in C


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QLoad(B*.al sender $s S*stem#


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using S*stem#Colle!tions#5eneri!

using S*stem#Com'onentModel

using S*stem#2ata

using S*stem#2rawing

using S*stem#Windows#orms

using S*stem#+untime#Intero'Seri!es

Nendregion

names'a!e CShar'Code

Z

'artial !lass orm> : orm

Z

R2llIm'ort(9ernelA#dll)

stati! etern int Slee'(long dwMillise!onds)

'uli! orm>()

Z

Initiali7eCom'onent()[

'riate oid orm>QLoad(o6e!t sender, &ent$rgs e)

0>

Z

MessageBo#Show(9Starting o" 111 ms###)

Slee'(111)

MessageBo#Show(9&nd o" 111 ms###)

[

[

[(B)When we use windows $EI in #%&T is it managed or unmanaged !ode

?

Windows $EI in #%&T is unmanaged !ode#

%ote:- &en though .B3 and . C// has gone o"" still man* 'eo'le do as these old

=uestions again and again#Still there are de!ent old a''li!ation whi!h are woring with

C


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o" deletion# In the methods that "ollow, the s*nta is shortened to ee' the s!o'e o" the

dis!ussion

rie" and manageale#

($) Can *ou des!rie IG%


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o" 're!ious andwidth used onl* "or 'inging#

The !lient has the !ontrol to set the !om'uter whi!h will e res'onsile "or the li"etime o" the

o6e!t# That is to sa*, these o6e!ts are not !reated 6ust somewhere where the s*stem resour!es

and

a!!ess 'riileges allow "or it#

Call se!urit* is im'lemented in all "our wa*s: authenti!ation (to 'reent "alse !lients "rom

im'ersonating the true !lient), authori7ation (to insure that a !lient onl* does what it is

authori7ed

to do), data integrit* (to insure that data was not tam'ered with during transit) and data 'ria!*

(to

insure that onl* designated sour!es !an read it)# The se!urit* issues are handled as the* are on

0A

o'erating s*stems# The !lient gies the serer arious a!!ess 'riileges to a!!ess memor* or dis

s'a!e

(B)ow do we !reate 2C


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ContetGtil#SetCom'lete()

[

!at!h(&!e'tion)

Z

OO Something went wrong $ort and +olla! the Transa!tion#

ContetGtil#Set$ort()

[

[

4 Com'onent deried "rom 9Seri!edCom'onent should e strong named as the*

run under C


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Euli! Su 2oWor()

F Method !ontents go here#

&nd Su

&nd Class

$oe is a sam'le !ode whi!h has the 9


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with a new orward e* !ontaining the alue o" this new inter"a!e I2# C)


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2im 'thread $s %ew Thread($ddress

Loo'

&nd Su

$oe is a sam'le !ode whi!h shows sim'le sam'le !ode "or threading##$oe sam'le

!ode !an e "ound in 9Threading "older in C2 'roided#$oe sam'le has two methods

9Thread>() and 9Thread() whi!h are started in multi-threaded mode in orm load

eent o" the sam'le#%ote :- I" *ou run the sam'le *ou will see that sometimes the "irst thread runs "irst and

then the se!ond thread#This ha''ens e!ause o" thread 'riorities #The "irst thread is run

with highest 'riorit*#

($)ow !an we !hange 'riorit* and what the leels o" 'riorit* are

'roided * #%&T ?

Thread Eriorit* !an e !hanged * using Threadname#Eriorit* V ThreadEriorit*#ighest#In

the sam'le 'roided loo out "or !ode where the se!ond thread is ran with a high 'riorit*#

>

ollowing are di""erent leels o" Eriorit* 'roided * #%&T :-

4 ThreadEriorit*#ighest

4 ThreadEriorit*#$oe%ormal

4 ThreadEriorit*#%ormal

4 ThreadEriorit*#Below%ormal

4 ThreadEriorit*#Lowest

($)What does $ddresso" o'erator do in a!ground ?

The $ddress


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has een instantiated, *ou egin the ee!ution o" the !ode * !alling the Start() method

o" the thread

($)ow !an *ou re"eren!e !urrent thread o" the method ?

HThread#CurrentThreadH re"ers to the !urrent thread running in the

method#HCurrentThreadH is a 'uli! stati! 'ro'ert*#

(I) WhatFs Thread#Slee'() in threading ?

ThreadFs ee!ution !an e 'aused * !alling the Thread#Slee' method# This method taes

an integer alue that determines how long the thread should slee'#&am'le

Thread#CurrentThread#Slee'(111)#

($)ow !an we mae a thread slee' "or in"inite 'eriod ?

Kou !an also 'la!e a thread into the slee' state "or an indeterminate amount o" time *

!alling Thread#Slee' (S*stem#Threading#Timeout#In"inite)#To interru't this slee' *ou !an

!all the Thread#Interru't method#

($) What is Sus'end and +esume in Threading ?

It is Similar to Slee' and Interru't# Sus'end allows *ou to lo! a thread until another

thread !alls Thread#+esume# The di""eren!e etween Slee' and Sus'end is that the latterdoes not immediatel* 'la!e a thread in the wait state# The thread does not sus'end until

the #%&T runtime determines that it is in a sa"e 'la!e to sus'end it# Slee' will immediatel*

'la!e a thread in a wait state#

%ote :- In threading interiews most 'eo'le get !on"used with Slee' and Sus'end#The* loo

er* similar#

($)What the wa* to sto' a long running thread ?

Thread#$ort() sto's the thread ee!ution at that moment itsel"#

($) ow do i deug thread ?

igure :- A#> 2eug thread windowThis window is onl* seen when the 'rogram is running in deug mode#In windows one o"

the window is 9Threads#

($)WhatFs Thread#Join() in threading ?

A

There are two ersions o" Thread#Join :-

4 Thread#6oin()#

4 Thread#6oin(Integer) this returns a oolean alue#

The Thread#Join method is use"ul "or determining i" a thread has !om'leted e"ore starting

another tas# The Join method waits a s'e!i"ied amount o" time "or a thread to end# I" the

thread ends e"ore the time-out, Join returns True otherwise it returns alse#


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2aemon?

2aemon threadFs run in a!ground and sto' automati!all* when nothing is running

'rogram#&am'le o" a 2aemon thread is H5arage !olle!torH#5arage !olle!tor runs

until some #%&T !ode is running or else its idle#

Kou !an mae a thread 2aemon *

Thread#Isa!groundVtrue

($) When woring with shared data in threading how do *ou im'lement

s*n!hroni7ation ?

There are a somethings *ou need to e !are"ul with when using threads# I" two threads

(e#g# the main and an* worer threads) tr* to a!!ess the same ariale at the same time,

*ouFll hae a 'rolem# This !an e er* di""i!ult to deug e!ause the* ma* not alwa*s do

it at ea!tl* the same time# To aoid the 'rolem, *ou !an lo! a ariale e"ore a!!essing

it# oweer, i" two threads lo! the same ariale at the same time, *ouFll hae a deadlo!

'rolem#

0

S*n!Lo! F2o something with

&nd S*n!Lo!

(I)Can we use eents with threading ?

Kes *ou !an use eents with threads , this is one o" the te!hni=ue to s*n!hroni7e one

thread with other#

($)ow !an we now a state o" a thread?

HThreadStateH 'ro'ert* !an e used to get detail o" a thread#Thread !an hae one or

!omination o" status#S*stem#Threading#Threadstate enumeration has all the alues to

dete!t a state o" thread#Some sam'le states are Isrunning,Is$lie,sus'ended et!#

($) What is use o" Interlo!ed !lass ?Interlo!ed !lass 'roides methods * whi!h *ou !an a!hiee "ollowing "un!tionalities :-

4 in!rement .alues#

4 2e!rement alues#

4 &!hange alues etween ariales#

4 Com'are alues "rom an* thread#

in a s*n!hroni7ation mode#

&am'le :- S*stem#Threading#Interlo!ed#In!rement(Int$)

($) what is a monitor o6e!t?

Monitor o6e!ts are used to ensure that a lo! o" !ode runs without eing interru'ted *

!ode running on other threads# In other words, !ode in other threads !annot run until

!ode in the s*n!hroni7ed !ode lo! has "inished#

S*n!Lo! and &nd S*n!Lo! statements are 'roided in order to sim'li"* a!!ess to monitor

o6e!t#

($) what are wait handles ?

Twist :- What is a mute o6e!t ?

Wait handles sends signals o" a thread status "rom one thread to other thread#There are


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three ind o" wait modes :-

4 Wait


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+emoting and Weseri!es(B)What is an a''li!ation domain?

Ereiousl* 9E+


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D

+emoting has atleast three se!tions :-

4 Common Inter"a!e whi!h will e shared etween them#

4 Serer#

4 Client#

igure :- 0#A Solution &'lorer o" +emoting Ero6e!t

In C2 9+emotingSam'le(S$


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Console#WriteLine(9Serer Started####)

o6tt'Channel V %ew tt'Channel(>A0)

ChannelSeri!es#+egisterChannel(o6tt'Channel)

+emotingCon"iguration#+egisterWellnownSeri!eT*'e(5etT*'e(+emotingSerer),

9+emoteA0O+emote


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Im'orts Intera!e+emoting

Module ModuleStartClient

Su Main()

2im o6tt'Channel $s %ew tt'Channel

2im o6+emoting $s Intera!e+emoting#Intera!e+emoting

ChannelSeri!es#+egisterChannel(o6tt'Channel)

o6+emoting V

CT*'e($!tiator#5etA0O+emote


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($) What are the wa*s !lient !an !reate o6e!t on serer in C$< model ?

There are two wa*s * whi!h *ou !an !reate Client o6e!ts on remoting serer :-

4 $!tiator#CreateInstan!e()#

4 B* e*word 9%ew#

30

($) $re C$< state"ul in nature ?

Kes#In C$< remoting model !lient !reates a instan!e on serer and instan!e ariale set

* !lient on serer !an e retrieed again with !orre!t alue#

($) In C$< model when we want !lient o6e!ts to e !reated * 9%&W

e*word is there an* 're!autions to e taen ?

+emoting Clients and +emoting Serer !an !ommuni!ate e!ause the* share a !ommon

!ontra!t * im'lementing Shared Inter"a!e or Base Class ($s seen in 'reious eam'les)#

But a!!ording to


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($) What is LeaseTime,S'onsorshi'Time ,+enewonCallTime and

LeaseManagerEollTime?

This is a er* im'ortant =uestion "rom 'ra!ti!al im'lementation 'oint o" iew#Com'anies

who hae s'e!i"i! re=uirement "or +emoting 'ro6e!t8s will e'e!t this =uestion to e answered#

In normal #%&T enironment o6e!ts li"etime is managed * garage !olle!tor#But in

remoting enironment remote !lients !an a!!ess o6e!ts whi!h is out o" !ontrol o" garage

!olle!tor#5arage !olle!tor oundar* is limited to a single EC on whi!h "ramewor is

running , an* remote !lient a!ross 'h*si!al EC is out o" !ontrol o" 5C (5arage Colle!tor)#

This !onstraint o" garage !olle!tor leads to a new wa* o" handling li"etime "or remoting

o6e!ts , * using !on!e't !alled as 9LeaseTime#&er* serer side o6e!t is assigned *

de"ault a 9LeaseTime o" "ie minutes#This leasetime is de!reased at !ertain interals#$gain

"or eer* method !all a de"ault o" two minutes is assigned#When i sa* method !all means

eer* !all made "rom !lient#This is !alled as 9+enewal) V >1 minutes (&er*thing is in

minutes)

33

When total o6e!t li"etime is redu!ed to 7ero , it =ueries the s'onsor that should the

o6e!t e destro*ed#S'onsor is a o6e!t whi!h de!ides should o6e!t Li"etime e

renewed#So it =ueries an* registered s'onsors with the o6e!t , i" does not "ind an* then

the o6e!t is mared "or garage !olle!tion#$"ter this garage !olle!tion has whole !ontrol

on the o6e!t li"etime#I" we do not "oresee how long a o6e!t will e needed s'e!i"* the

9S'onsorShi'Time


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whi!h we where 'roiding through !ode#

!on"igurationU

s*stem#runtime#remotingU

a''li!ation nameVSererU

seri!eU

wellnown

3@

modeVSingleCall

t*'eVSerer#ClsSerer, Serer

o6e!tGriV+emote


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o6Seri!e&ntries V

+emotingCon"iguration#5et+egisteredWellnownClientT*'es()

Io6Common V $!tiator#5et


30/124


31/124

We Seri!e 2es!ri'tion Language (WS2L)is a WAC s'e!i"i!ation whi!h de"ines ML

grammar "or des!riing We Seri!es#ML grammar des!ries details su!h as:-

4 Where we !an "ind the We Seri!e (its G+I)

4 What methods and 'ro'erties that seri!e su''orts

4 2ata t*'e su''ort#

4 Su''orted 'roto!ols

In short its a ile o" what the weseri!e !an do#Clients !an !onsume this WS2L and

uild 'ro* o6e!ts that !lients use to !ommuni!ate with the We Seri!es# ull WS2L

s'e!i"i!ation is aailale at htt':OOwww#wA#orgOT+Owsdl#

($) What the di""erent 'haseOste's o" a!=uiring a 'ro* o6e!t in

Weseri!e ?

The "ollowing are the di""erent ste's needed to get a 'ro* o6e!t o" a weseri!e at the

!lient side :-

4 Client !ommuni!ates to G2I node "or WeSeri!e either through rowser or

G22IFs 'uli! we seri!e#

4 G2II res'onds with a list o" weseri!e#4 &er* seri!e listed * weseri!e has a G+I 'ointing to 2ISC< or WS2L

do!ument#

A

4 $"ter 'arsing the 2ISC< do!ument, we "ollow the G+I "or the WS2L do!ument

related to the weseri!e whi!h we need#

4 Client then 'arses the WS2L do!ument and uilds a 'ro* o6e!t whi!h !an

!ommuni!ate with Weseri!e#

(B) What is "ile etension o" Weseri!es ?

#$SM is etension "or Weseri!es#

%ote :- $"ter this we are going to deal with a sam'le o" weseri!e#In .S11 we'ro6e!tis !reated "rom the menu itsel" as !om'ared to 11A where it was 'resent in the e'lorer#

0

igure :- 0#@ Create We 'ro6e!t menu in .S11

(B)Whi!h attriute is used in order that the method !an e used as

WeSeri!e ?

WeMethod attriute has to e s'e!i"ied in order that the method and 'ro'ert* !an e

treated as WeSeri!e#

($) What are the ste's to !reate a weseri!e and !onsume it ?

%ote :- or this =uestion this oo will mae a attem't * !reating a sim'le weseri!e and

e'laining ste's to a!heie it#$ sim'le weseri!e will e !reated whi!h taes two numer

and gies addition result o" the two numer#In C2 sam'le weseri!e 'ro6e!t with "older

name 9MathsWeSeri!e is 'roided and same will e e'lained elow# 2e"initel* the

interiewer will not e'e!t su!h a detail answer ut this oo will e'lain *ou in detail so

that *ou are on right tra! during interiew#

This weseri!e will add two numers and gie to the !alling !lient#$ll the elow ste's

are a!!ording to .S11 eta editor :-


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4 irst !reate a wesite * !li!ing on ile -- %ew WeSite#

4 rom 9.isual Studio Installed Tem'lates !li! on 9$s'#%&T We Seri!e#See

"igure elow#%ame the "igure as 9Maths We Seri!e#

igure :- 0#D Create WeSeri!e Ero6e!t

3

4 B* de"ault the #%&T editor has made a de"ault weseri!e method !alled as

HelloWordH whi!h returns a string datat*'e#LetFs rename HSeri!e#H to

HMaths#H and HSeri!e#asmH to HMaths#asmH#Let8s re'la!e the

9elloWorld with "ollowing !ode elow :-

WeMethod()U Q

Euli! un!tion $ddTwo%umers(B*.al %umer> $s Integer, B*.al

%umer $s Integer) $s Integer

+eturn %umer> / %umer

&nd un!tion

igure :- 0#>1 +ename all *our de"ault 9Seri!e to 9Maths4

4 $"ter the weseri!e is done !li! on add Were"eren!e#%ormall* "or

!om'onents we do a 9$dd +e"eren!e and "or Weseri!es we do 9$dd We

+e"eren!e#

igure :- 0#>> Cli! on $dd We +e"eren!e

@

4 Kou will e shown with a list o" weseri!es whi!h are nown to the

solutions#$s we are looing "or our 9Maths weseri!e whi!h eist in the same

solution , we !li! 9Weseri!es in this solution#

Digure :- 0#> List o" weseri!es "or rowsing

4 Kour editor has lo!ated the 9Maths weseri!e#Sele!t the weseri!e#

igure :- 0#>A Solution showing the aailailit* o" Maths Weseri!e#

@1

@>

4 $"ter *ou hae !li!ed on 9Maths weseri!e *ou will see a sear!h 'rogress

ar as shown in "igure elow#This 'ro!ess will start the weseri!e , re"eren!e it

and !reate a 'ro* "or the !lient , so that using it !lient !an asor the

weseri!e#

igure :- 0#>0 Starting the weseri!e and !reating the 'ro* "or *our solution#

@

4 inall* *ou are ale to see *our weseri!e whi!h is read* "or use#Cli! on

$dd +e"eren!e and *ou will see a 9Lo!alhost re"eren!e in *our #%&T solution#

igure :- 0#> Starting the weseri!e and !reating the 'ro* "or *our solution#

4 We need to mae a !lient who will asor this 9Maths Weseri!e#$dd

9Weseri!eClient#as' and !reate a GI as shown elow#In the utton !li!

'ut in the "ollowing !ode#Lo!alost#ClsMaths is the 'ro* o6e!t * whi!h


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*ou !an mae !alls to the weseri!e#

Su !mdCal!ulateQCli!(B*.al sender $s


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(B) What is a''li!ation o6e!t ?

$''li!ation o6e!t !an used in situation where we want data to e shared a!ross users

gloall*#

(I)What8s the di""eren!e etween Ca!he o6e!t and a''li!ation o6e!t ?

The main di""eren!e etween the Ca!he and $''li!ation o6e!ts is that the Ca!he o6e!t

'roides !a!he-s'e!i"i! "eatures, su!h as de'enden!ies and e'iration 'oli!ies#

(I)ow !an get a!!ess to !a!he o6e!t ?

The Ca!he o6e!t is de"ined in the S*stem#We#Ca!hing names'a!e# Kou !an get a re"eren!e

to the Ca!he o6e!t * using the Ca!he 'ro'ert* o" the tt'Contet !lass in the

S*stem#We names'a!e or * using the Ca!he 'ro'ert* o" the Eage o6e!t#

($)What are de'enden!ies in !a!he and t*'es o" de'enden!ies ?

When *ou add an item to the !a!he, *ou !an de"ine de'enden!* relationshi's that !an

"or!e that item to e remoed "rom the !a!he under s'e!i"i! a!tiities o"

de'enden!ies#&am'le i" the !a!he o6e!t is de'endent on "ile and when the "ile data

!hanges *ou want the !a!he o6e!t to e u'date#ollowing are the su''orted de'enden!*

:-

4 ile de'enden!* :- $llows *ou to inalidate a s'e!i"i! !a!he item when a dis

ased "ile or "iles !hange#

4 Time-ased e'iration :- $llows *ou to inalidate a s'e!i"i! !a!he itemde'ending on 'rede"ined time#

4 e* de'enden!* :-$llows *ou to inalidate a s'e!i"i! !a!he item de'ending

when another !a!hed item !hanges#

# Ca!hing Con!e'ts

@

(E)Can *ou show a sim'le !ode showing "ile de'enden!* in !a!he ?

Eartial Class 2e"aultQas'

Euli! Su dis'la*$nnoun!ement()

2im announ!ement $s String

I" Ca!he(9announ!ement) Is %othing Then

2im "ile $s %ew QS*stem#I


35/124

"ile whi!h is l*ing in a''li!ation 'ath o" the we dire!tor*#$oe method "irst !he!s is

the Ca!he o6e!t nothing , i" the !a!he o6e!t is nothing then it moes "urther to load the

!a!he data "rom the "ile#Wheneer the "ile data !hanges the !a!he o6e!t is remoed and

set to nothing#

($) What is Ca!he Calla! in Ca!he ?

Ca!he o6e!t is de'endent on its de'enden!ies eam'le "ile ased , time ased et!#Ca!he

items remoe the o6e!t when !a!he de'enden!ies !hange#$SE#%&T 'roides !a'ailit*

to ee!ute a !alla! method when that item is remoed "rom !a!he#

@3

($) What is s!aenging ?

When serer running *our $SE#%&T a''li!ation runs low on memor* resour!es , items

are remoed "rom !a!he de'ending on !a!he item 'riorit*#!a!he item 'riorit* is set when

*ou add item to !a!he#BK setting the !a!he item 'riorit* !ontrols whi!h items s!aenging

is remoed "irst#

(B) What are di""erent t*'es o" !a!hing using !a!he o6e!t o" $SE#%&T?

Kou !an use two t*'es o" out'ut !a!hing to !a!he in"ormation that is to e transmitted to

and dis'la*ed in a We rowser:

4 Eage


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4 $SE session state is de'endent on IIS 'ro!ess er* heail*#So i" IIS restarts

$SE session ariales are also re!*!led#$SE#%&T session !an e inde'endent

o" the hosting enironment thus $SE#%&T session !an maintained een i" IIS

reoots#

4 $SE session state has no inherent solution to wor with We arms#$SE#%&T

session !an e stored in state serer and S\L S&+.&+ whi!h !an su''ort

multi'le serer#

4 $SE session onl* "un!tions when rowser su''orts !ooies#$SE#%&T session

!an e used with rowser side !ooies or inde'endent o" it#

(B) Whi!h arious modes o" storing $SE#%&T session ?

4 InEro!:- In this mode Session state is stored in the memor* s'a!e o" the

$s'netQw'#ee 'ro!ess#This is the de"ault setting#I" the IIS reoots or we

a''li!ation restarts then session state is lost#

@@

4 StateSerer:-In this mode Session state is seriali7ed and stored in a se'arate

'ro!ess ($s'netQstate#ee) there"ore, the state !an e stored on a se'arate

!om'uter(a state serer)#

4 S\L S&+.&+:- In this mode Session state is seriali7ed and stored in a S\L

Serer dataase#Session state !an e s'e!i"ied in sessionStateU element o" a''li!ation !on"iguration

"ile#Gsing State Serer and S\L S&+.&+ session state !an e shared a!ross we "arms

ut note this !omes at s'eed !ost as $SE#%&T needs to seriali7e and deseriali7e data oer

networ again and again#

($) Is SessionQ&nd eent su''orted in all session modes ?

SessionQ&nd eent o!!urs onl* in 9In'ro! mode#State Serer and 9S\L S&+.&+

do not hae SessionQ&nd eent#

($) What are the 're!autions *ou will tae in order that StateSerer Mode

wor 'ro'erl* ?

ollowing are the things to rememer so that StateSerer Mode wors 'ro'erl* :-

4 StateSerer mode session data is stored in a di""erent 'ro!ess so *ou mustensure that *our o6e!ts are seriali7ale#

4 ma!hinee*U elements in We#!on"ig should e indenti!al a!ross all

serers#So this ensures that en!r*'tion "ormat is same a!ross all !om'uters#

4 IIS metaase (LMWAS.C) must e identi!al a!ross all serers in that

"arm#

($) What are the 're!autions *ou will tae in order that S\LS&+.&+

Mode wor 'ro'erl* ?

ollowing are the things to rememer so that S\LS&+.&+ Mode wors 'ro'erl* :-

4 S\LS&+.&+ mode session data is stored in a di""erent 'ro!ess so *ou must

ensure that *our o6e!ts are seriali7ale#

4 IIS metaase (LMWAS.C) must e indenti!al a!ross all serers in that

"arm#

@D

4 B* de"ault Session o6e!ts are stored in 9Tem'd , *ou !an !on"igure it store

outside 9Tem'2B * running mi!roso"t 'roided S\L s!ri't#

%ote :- 9Tem'2B dataase is re-!reated a"ter S\L S&+.&+ !om'uter reoot#I" *ou

want to maintain session state with eer* reoot est is to run S\L S!ri't and store session

o6e!ts outside 9Tem'2B dataase#

($) Where do *ou s'e!i"* session state mode in $SE#%&T ?

sessionState modeVS\LSerer


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stateConne!tionStringVt!'i'V>D#>3@#>#>:000H

s=lConne!tionStringVdata sour!eV>D#>3@#>#> Integrated

Se!urit*VSSEI

!ooielessV"alse

timeoutV1H

OU

$oe is sam'le session state mode s'e!i"ied "or S\L S&+.&+#

(B) What are the other wa*s *ou !an maintain state ?


38/124

D>

4 .iew state is good "or !a!hing data in We "arm !on"igurations e!ause the

data is !a!hed on the !lient#

ollowing are limitation o" using .iewstate:-

4 Eage loading and 'osting 'er"orman!e de!reases when large alues are

stored e!ause iew state is stored in the 'age#

4 $lthough iew state stores data in a hashed "ormat, it !an still e tam'ered

with e!ause it is stored in a hidden "ield on the 'age# The in"ormation in the

hidden "ield !an also e seen i" the 'age out'ut sour!e is iewed dire!tl*,

!reating a 'otential se!urit* ris#

Below is sam'le o" storing alues in iew state#

this#.iewStateRH&nterTimeH V 2ateTime#%ow#ToString()

(B) ow an *ou use idden "rames to !a!he !lient data ?

This te!hni=ue is im'lemented * !reating a idden "rame in 'age whi!h will !ontain

*our data to e !a!hed#

+$M&S&T !olsVH>11_,;,;HU

+$M&S&T rowsVH>11_HU

+$M& sr!VHdataQo"Q"rame>#htmlHUO+$M&S&TU

+$M& sr!VHdataQo"QhiddenQ"rame#htmlHU+$M& sr!VHdataQo"QhiddenQ"rame#htmlH "rameorderVH1H noresi7e

s!rollingVH*esHU

O+$M&S&TU

$oe is a sam'le o" hidden "rames where the "irst "rame 9dataQo"Q"rame>#html is isile

and the remaining "rames are hidden * giing whole !ol se!tion to "irst "rame# See allo!ation

where >11 _ is allo!ated to "irst "rame and remaining "rames thus remain hidden#

(I) What are ene"its and Limitation o" using idden "rames?

ollowing are the ene"its o" using hidden "rames:

4 Kou !an !a!he more than one data "ield#

D

4 The ailit* to !a!he and a!!ess data items stored in di""erent hidden "orms#4 The ailit* to a!!ess JS!ri't ariale alues stored in di""erent "rames i" the*

!ome "rom the same site#

The limitations o" using hidden "rames are:

4 idden "rames are not su''orted on all rowsers#

4 idden "rames data and e tam'ered thus !reating se!urit* hole#

(I) What are ene"its and Limitation o" using Cooies?

ollowing are ene"its o" using !ooies "or state management :-

4 %o serer resour!es are re=uired as the* are stored in !lient#

4 The* are light weight and sim'le to use

ollowing are limitation o" using !ooies :-

4 Most rowsers 'la!e a 01D3-*te limit on the si7e o" a !ooie,although su''ort

"or @>D-*te !ooies is e!oming more !ommon in the new rowser and

!lient-dei!e ersions aailale toda*#

4 Some users disale their rowser or !lient dei!e8s ailit* to re!eie !ooies,

there* limiting the use o" !ooies#

4 Cooies !an e tam'ered and thus !reating a se!urit* hole#

4 Cooies !an e'ire thus leading to in!onsisten!*#

Below is sam'le !ode o" im'lementing !ooies

+e=uest#Cooies#$dd(%ew tt'Cooie(9name, 9user>))

(I) What is \uer* String and What are ene"its and Limitation o" using


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\uer* Strings?

$ =uer* string is in"ormation sent to the serer a''ended to the end o" a 'age G+L#

ollowing are the ene"its o" using =uer* string "or state management:-

4 %o serer resour!es are re=uired# The =uer* string is !ontained in the TTE

re=uest "or a s'e!i"i! G+L#

DA

4 $ll rowsers su''ort =uer* strings#

ollowing are limitations o" =uer* string :-

4 \uer* string data is dire!tl* isile to user thus leading to se!urit* 'rolems#-

4 Most rowsers and !lient dei!es im'ose a -!hara!ter limit on G+L length#

Below is a sam'le 9Login =uer* string 'assed in G+L htt':OOwww#=uer*string#!omO

login#as'?loginVtesting#This =uer*string data !an then e re=uested later * using

+e=uest#\uer*String(9login)#

11 m s'eed and urgent raes#

(B) What are di""erent 'ro'erties 'roided *


40/124

D

$stra!tion

It allows !om'le real world to e re'resented in sim'li"ied manner#&am'le !olor is

astra!ted to +5B#B* 6ust maing the !omination o" these three !olors we !an a!hiee

an* !olor in world#It8s a model o" real world or !on!e't#

&n!a'sulation

The 'ro!ess o" hiding all the internal details o" an o6e!t "rom the outside world#

Communi!ation using messages

When a''li!ation wants to a!hiee !ertain tas it !an onl* e done using !omination o"

o6e!ts#$ single o6e!t !an not do all the tas#&am'le i" we want to mae order 'ro!essing

"orm# We will use Customer o6e!t ,


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%ote:- The "ollowing e'lanation is "or .B#%&T

Inheritan!e is a!hieed * using 9Inherits e*word in .B#%&T (or CN it is 9:)#Sim'le

Sam'le is 'roided in C2 "or understanding inheritan!e in "older

9Windows$''li!ationInheritan!e#There are two !lasses one is the 'arent 9ClsEarent

and se!ond is the !hild 9ClsChild#Earent !lass has a string whi!h has to 'arsed "or 6un

data 9` and 9O#ClsEarent has the "un!tionalit* whi!h 'arses onl* !leans u'

9`#ClsChild then inherits "rom 'arent and adds etra "un!tionalit* * 'arsing 9O#

Euli! Class ClsEarent

Erote!ted str2ata $s String V 96sdh6`dadadOOOa6dhs6ad

Euli! un!tion Earse() $s String

2im Estr2ata $s String

Estr2ata V str2ata

Estr2ata V +e'la!e(Estr2ata, 9`, 9)

+eturn Estr2ata

&nd un!tion

Euli! un!tion 5et$!tualString() $s String+eturn str2ata

&nd un!tion

&nd Class

$oe is the sour!e whi!h 'arses onl* 9` o" str2ata ariale#

; What gies *our greatest satis"a!tion in so"tware 'ro"ession ?

D

Euli! Class ClsChild

Inherits ClsEarent

X this is !hild and a s'e!ial 'arse "un!tion is added whi!h will

also 'arse 9OEuli! un!tion EarseBa!Slash()

2im Estr2ata $s String

Estr2ata V Me#Earse()

Estr2ata V +e'la!e(Estr2ata, 9O, 9)

+eturn Estr2ata

&nd un!tion

&nd Class

$oe is the sour!e !ode "or 9ClsChild whi!h does the remaining wor#It adds etra

"un!tionalit* * 'arsing 9O 6un !hara!ter8s o" the data#

%ote:- Strdata was a!!essile onl* e!ause it was de"ined as 'rote!ted in the 'arent !lass#

igure :- 3#> Inheritan!e in a!tion

(I) What are astra!t !lasses ?

ollowing are "eatures o" a astra!t !lass :-

4 Kou !an not !reate a o6e!t o" astra!t !lass

; ow would *ou des!rie *oursel" ?

D@

4 $stra!t !lass is designed to a!t as a ase !lass (to e inherited * other !lasses)#


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$stra!t !lass is a design !on!e't in 'rogram deelo'ment and 'roides a

ase u'on whi!h other !lasses are uilt#

4 $stra!t !lasses are similar to inter"a!es# $"ter de!laring an astra!t !lass, it

!annot e instantiated on itFs own, it must e inherited#

4 In .B#%&T astra!t !lasses are !reated using 9MustInherit e*word#In CN

we hae 9$stra!t e*word#

4 $stra!t !lasses !an hae im'lementation or 'ure astra!t methods whi!h

should e im'lemented in the !hild !lass#

%ote:- In order to understand the !on!e't sim'le sam'le o" add and multi'l* "un!tionalit*

is im'lemented in 9Windows$stra!t "older in C2#

rom interiew 'oint o" iew 6ust sa*ing using 9MustInherit e*word is more than enough

to !onin!e that *ou hae used astra!t !lasses#But to !lear sim'le "undamental let8s tr*

to understand the sam'le !ode#There are two !lasses one is 9Cls$stra!t !lass and other

is 9ClsChild !lass#Cls$stra!t !lass is a astra!t !lass as *ou !an see the mustinherit

e*word#It has one im'lemented method 9$dd and other is astra!t method whi!h has

to e im'lemented * !hild !lass 9Multi'l*%umer#In the !hild !lass we inherit theastra!t !lass and im'lement the multi'l*numer "un!tion#

2e"initel* this sam'le does not tae out a!tuall* how things are im'lemented in lie

'ro6e!ts#Basi!all* *ou 'ut all *our !ommon "un!tionalities or hal" im'lemented

"un!tionalit* in 'arent astra!t !lass and later let !hild !lass de"ine the "ull "un!tionalit*

o" the astra!t !lass#&am'le i alwa*s use astra!t !lass with all m* S&T 5&T 'ro'erties

o" o6e!t in astra!t !lass and later mae s'e!iali7e !lasses "or insert,u'date,delete "or

the !orres'onding entit* o6e!t#

Euli! MustInherit Class Cls$stra!t

X use the mustinherit !lass to de!lare the !lass as astra!t

Euli! un!tion $dd(B*.al intnum> $s Integer, B*.al intnum $sInteger) $s Integer

+eturn intnum> / intnum

&nd un!tion

X le"t this se!on" "un!tion to e !om'leted * the inheriting

!lass

Euli! Must $s

Integer, B*.al intnum $s Integer) $s Integer

+eturn intnum> ; intnum

&nd un!tion


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&nd Class

igure :- 3# $stra!t !lasses in a!tion

M* attitude towards astra!t !lass has een that i 'ut all m* !ommon "un!tionalit* in

astra!t !lass#

(B) What8s a Inter"a!e ?

Inter"a!e is a !ontra!t that de"ines the signature o" the "un!tionalit*#So i" a !lass is

im'lementing a inter"a!e it sa*s to the outer world , that it 'roides s'e!i"i! ehaior #

&am'le i" a !lass is im'lementing Idis'osale inter"a!e that means it has a "un!tionalit*

to release unmanaged resour!es # %ow eternal o6e!ts using this !lass nows that it has

!ontra!t * whi!h it !an dis'ose unused unmanaged o6e!ts#

4 Single Class !an im'lement multi'le inter"a!es#

4 I" a !lass im'lements a inter"a!e then it has to 'roide im'lementation to all

its methods#

>11

%ote:- In C2 sam'le 9WindowsIntera!e is 'roided , whi!h has a sim'le inter"a!e

im'lemented#In sam'le there are two "iles#1>

($) What is di""eren!e etween astra!t !lasses and

inter"a!es?

ollowing are the di""eren!es etween astra!t and inter"a!es :-

4 $stra!t !lasses !an hae !on!rete methods while inter"a!es hae no methods

im'lemented#

4 Inter"a!es do not !ome in inheriting !hain , while astra!t !lasses !ome in

inheritan!e#

(B) What is a delegate ?

2elegate is a !lass that !an hold a re"eren!e to a method or a "un!tion#2elegate !lass has

a signature and it !an onl* re"eren!e those methods whose signature is !om'liant with the

!lass#2elegates are t*'e-sa"e "un!tions 'ointers or !alla!s#


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Below is a sam'le !ode whi!h shows a eam'le o" how to im'lement delegates#

Euli! Class rm2elegates

Inherits S*stem#Windows#orms#orm

Euli! 2elegate Su 2elegate$ddString()

Eriate Su rm2elegatesQLoad(B*.al sender $s S*stem#


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>1A

Euli! Class rmWith&ents


Eriate With&ents mo6ClsWith&ents $s %ew ClsWith&ents()

Eriate Su rmWith&entsQLoad(B*.al sender $s S*stem#


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&nd Class

; Wh* should i hire *ou ?

>1

igure :- 3#3 Shadowing in $!tion

($) What8s di""eren!e etween Shadowing and

13

Just imagine one o" *our !lients doing this

!#*7Calla! V null

This will reset all *our delegates to nothing and *ou hae to ee' "iguring where the error

is#

(B) I" we inherit a !lass do the 'riate ariales also get

inherited ?Kes the ariales are inherited ut !an not e a!!essed dire!tl* * the !lass inter"a!e#

(B) What are di""erent a!!essiilit* leels de"ined in

#%&T ?

ollowing are the "ie leels o" a!!ess modi"iers :-

4 Eriate :


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e*word#This a!ts onl* as ase t*'e and !an not e inherited an* "urther#Kou !an not

!reate a o6e!t o" a !lass whi!h is mared as 9MustInherit#

;What hae *our learnt "rom *our 'ast 'ro6e!t e'erien!es ?

>1

(I) Wh* !an not *ou s'e!i"* a!!essiilit* modi"ier in

Inter"a!e ?

$ll elements in Inter"a!e should e 'uli!#So * de"ault all inter"a!e elements are 'uli!

* de"ault#

($) What are similarities etween Class and stru!ture ?

ollowing are the similarities etween !lasses and stru!tures :-

4 Both !an hae !onstru!tors, methods, 'ro'erties, "ields, !onstants,

enumerations, eents, and eent handlers#

4 Stru!tures and !lasses !an im'lement inter"a!e#

4 Both o" them !an hae !onstru!tors without 'arameter and with 'arameter#

4 Both !an hae delegates and eents#

($) What8s the di""eren!e etween Class andstru!ture8s ?

ollowing are the e* di""eren!es etween them :-

4 Stru!ture are alue t*'es and !lasses are re"eren!e t*'es#So stru!tures use

sta! and !lasses use hea'#

4 Stru!tures memers !an not e de!lared as 'rote!ted , ut !lass memers !an

e#Kou !an not do inheritan!e in stru!tures#

4 Stru!tures do not re=uire !onstru!tors while !lasses re=uire#

4 1@

Stati!OShared !lasses are used when a !lass 'roides "un!tionalit* whi!h is not s'e!i"i! to

an* instan!e#In short i" *ou want a o6e!t to e shared etween multi'le instan!es *ou

will use a stati!OShared !lass#

ollowing are "eatures o" Stati!OShared !lasses :-

4 The* !an not e instantiated#B* de"ault a o6e!t is !reated on the "irst method

!all to that o6e!t#

4 Stati!OShared !lasses !an not e inherited#

4 Stati!OShared !lasses !an hae onl* stati! memers#

4 Stati!OShared !lasses !an hae onl* stati! !onstru!tor#

%ote :- In C2 there is a "older 9WindowsShared whi!h has a sam'le !ode "or shared

ariales#Below is a sni''et#It has a 9$ddCount "un!tion whi!h in!rements a stati!

9intCount ariale#In "orm there are two uttons whi!h !reates a new o6e!t and dis'la*s

the !ount o" the stati! ariale#&en though the o6e!t is !reated and destro*ed , the ariale


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alues does not !hange#It retains its old alue#

Euli! Class ClsShared

Shared intCount $s Integer

Euli! un!tion $ddCount() $s Integer

intCount V intCount / >

+eturn intCount

&nd un!tion

&nd Class

Euli! Class rmSharedClasses


Eriate Su CmdInstan!e>QCli!(B*.al sender $s S*stem##Cli!

2im 'o6ClsShared $s %ew ClsShared()

MessageBo#Show(9The !ount at this moment is

'o6ClsShared#$ddCount#ToString())

&nd SuEriate Su CmdInstan!eQCli!(B*.al sender $s S*stem#


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($) What8s a ashTale ?

Twist :- What8s di""eren!e etween ashTale and $rra*List ?

Kou !an a!!ess arra* using I%2& alue o" arra* , ut how man* times *ou now the

real alue o" inde#ashtale 'roides wa* o" a!!essing the inde using a user identi"ied

&K alue , thus remoing the I%2& 'rolem#

($) What are =ueues and sta!s ?

\ueue is "or "irst-in, "irst-out (I


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&nd Class

; I leae this to the readers######

(B)What8s the signi"i!an!e o" inali7e method in #%&T?

#%&T 5arage !olle!tor does almost all !lean u' a!tiit* "or *our o6e!ts# But unmanaged

resour!es (e: - Windows $EI !reated o6e!ts, ile, 2ataase !onne!tion o6e!ts, C

whi!h !an e oerridden and !lean u' !ode "or unmanaged resour!es !an e 'ut in this

se!tion#

($)Wh* is it 're"erred to not use "inali7e "or !lean u'?

Erolem with "inali7e is that garage !olle!tion has to mae two rounds in order to remoe

o6e!ts whi!h hae "inali7e methods#

Below "igure will mae things !lear regarding the two rounds o" garage !olle!tion rounds

'er"ormed "or the o6e!ts haing "inali7ed methods#

In this s!enario there are three o6e!ts , >A

igure :- 3#@ 5arage !olle!tion in a!tions

(I)ow !an we su''ress a "inali7e method?

5C#Su''ressinali7e ()

(B)What8s the use o" 2ISE


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%ote :- I admire this =uestion#

Call the 2is'ose method in inali7e method and in 2is'ose method su''ress the "inali7e

method using 5C#Su''ressinali7e# Below is the sam'le !ode o" the 'attern# This is the

est wa* we do !lean our unallo!ated resour!es and *es not to "orget we do not get the hit

o" running the 5arage !olle!tor twi!e#

%ote:- It will su''ress the "inali7e method thus aoiding the two tri'#

Euli! Class ClsTesting

Im'lements I2is'osale

Euli!


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S*stem#String is immutale S*stem#StringBuilder !an hae mutale string where a ariet*

o" o'erations !an e 'er"ormed#

$SE#%&T

(B) What8s the se=uen!e in whi!h $SE#%&T eents are'ro!essed ?

ollowing are the se=uen!e in whi!h the eents o!!ur :-

4 EageQInit#

4 EageQLoad#

4 Control eents

4 EageQGnload eent#

EageQinit eent onl* o!!urs when "irst time the 'age is started , ut EageQLoad o!!urs in

suse=uent re=uest o" the 'age#

(B) In whi!h eent are the !ontrols "ull* loaded ?

EageQload eent guarantees that all !ontrols are "ull* loaded#Controls are also a!!essed in

EageQInit eents ut *ou will see that iewstate is not "ull* loaded during this eent#

(B) ow !an we identi"* that the Eage is EostBa! ?

Eage o6e!t has a 9IsEostBa! 'ro'ert* whi!h !an e !he!ed to now that is the 'age

'osted a!#

(B) ow does $SE#%&T maintain state in etween

suse=uent re=uest ?

+e"er !a!hing !ha'ter#

($) What is eent uling ?

Serer !ontrols lie 2atagrid , 2ataList , +e'eater !an hae other !hild !ontrols inside

them#&am'le 2ata5rid !an hae !omo o inside datagrid#These !hild !ontrol do not

raise there eents * themseles , rather the* 'ass the eent to the !ontainer 'arent

(whi!h !an e a datagrid , datalist , re'eater) , whi!h 'assed to the 'age as 9ItemCommand

eent#

>>

(B) ow do we assign 'age s'e!i"i! attriutes ?

Eage attriutes are s'e!i"ied using the `Eage dire!tie#

($) $dministrator wants to mae a se!urit* !he! that no

one has tam'ered with .iewState , how !an we ensure this ?

Gsing the `Eage dire!tie &nale.iewStateMa! to True#(B) What8s the use o" +egister dire!ties ?

`+egister dire!tie in"orms the !om'iler o" an* !ustom serer !ontrol added to the

'age#

(B) What8s the use o" Smart%aigation 'ro'ert* ?

It8s a "eature 'roided * $SE#%&T to 'reent "li!ering and redrawing when the 'age is

'osted a!#

%ote:- This is onl* su''orted "or I& rowser#Ero6e!t8s who hae rowser !om'atiilit* as


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re=uirement hae to thin some other wa*s o" aoiding "li!ering#

(B) What is $''Setting Se!tion in 9We#Con"ig "ile ?

We#!on"ig "ile de"ines !on"iguration "or a we'ro6e!t#Gsing 9$''Setting se!tion we !an

de"ine user de"ined alues#&am'le elow de"ined is 9Conne!tionString se!tion whi!h

will e used through out the 'ro6e!t "or dataase !onne!tion#

!on"igurationU

a''SettingsU

add e*VHConne!tionStringH alueVHsererV*7'wdVwwwdataaseVtestingH OU

Oa''SettingsU

(B) Where is .iewState in"ormation stored ?

In TML idden ields#

>>@

(I) What8s the use o" ` >D

Custom.alidator

Gsed to de"ine Gser2e"ined alidation#

.alidationSummar*

2is'la*s summar* o" all !urrent alidation errors#

%ote:- ItFs rare that some one will as ste' * ste' all the alidation !ontrols#&am'le in

one o" the interiews i was ased how do *ou dis'la* summar* o" all errors in the

alidation !ontrol###So there goes the last one#


54/124

(B) Can *ou e'lain what is 9$utoEostBa! "eature in

$SE#%&T ?

I" we want the !ontrol to automati!all* 'osta! in !ase o" an* eent , we will need to

!he! this attriute as true#&am'le on a ComoBo !hange we need to send the eent

immediatel* to the serer side then set the 9$utoEostBa! attriute to true#

(B) ow !an *ou enale automati! 'aging in 2ata5rid ?

ollowing are the 'oints to e done in order to enale 'aging in 2atagrid :-

4 Set the 9$llowEaging to true#

4 In EageIndeChanged eent set the !urrent 'ageinde !li!ed#

%ote:- The answers are er* short , i" *ou hae im'lemented 'ra!ti!all* its 6ust a

reision#I" *ou are "resher 6ust mae sam'le !ode using 2atagrid and tr* to im'lement this

"un!tionalit*#

(B) What8s the use o" 95L


55/124

is 'ro!ess where we !he! does this identit* hae a!!ess rights to the s*stem# In short we

!an sa* the "ollowing authenti!ation is the 'ro!ess o" otaining some sort o" !redentials

"rom the users and using those !redentials to eri"* the user8s identit*# $uthori7ation is

the 'ro!ess o" allowing an authenti!ated user a!!ess to resour!es# $uthenti!ation is alwa*s

're!edes to $uthori7ation een i" *our a''li!ation lets anon*mous users !onne!t and

use the a''li!ation, it still authenti!ates them as eing anon*mous#

>>

(I) What is im'ersonation in $SE#%&T ?

B* de"ault, $SE#%&T ee!utes in the se!urit* !ontet o" a restri!ted user a!!ount on the

lo!al ma!hine# Sometimes *ou need to a!!ess networ resour!es su!h as a "ile on a shared

drie, whi!h re=uires additional 'ermissions#


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4 authenti!ation modeV'ass'ortU

4 authenti!ation modeV"ormsU

4 Custom authenti!ation where *ou might install an IS$EI "ilter in IIS that

!om'ares in!oming re=uests to list o" sour!e IE addresses, and !onsiders

re=uests to e authenti!ated i" the* !ome "rom an a!!e'tale address# In that

!ase, *ou would set the authenti!ation mode to none to 'reent an* o" the

#net authenti!ation 'roiders "rom eing triggered#

Windows authenti!ation and IIS

I" *ou sele!t windows authenti!ation "or *our $SE#%&T a''li!ation, *ou also hae to

!on"igure authenti!ation within IIS# This is e!ause IIS 'roides Windows authenti!ation#

IIS gies *ou a !hoi!e "or "our di""erent authenti!ation methods:

$non*mous, asi! digest and windows integrated

I" *ou sele!t anon*mous authenti!ation, IIS doesn8t 'er"orm an* authenti!ation, $n* one

is allowed to a!!ess the $SE#%&T a''li!ation#

I" *ou sele!t asi! authenti!ation, users must 'roide a windows username and 'assword

to !onne!t# ow eer this in"ormation is sent oer the networ in !lear tet, whi!h maesasi! authenti!ation er* mu!h inse!ure oer the internet#

I" *ou sele!t digest authenti!ation, users must still 'roide a windows user name and

'assword to !onne!t# oweer the 'assword is hashed e"ore it is sent a!ross the networ#

2igest authenti!ation re=uires that all users e running Internet &'lorer or later and

that windows a!!ounts to stored in a!tie dire!tor*#

I" *ou sele!t windows integrated authenti!ation, 'asswords neer !ross the networ#

Gsers must still hae a username and 'assword, ut the a''li!ation uses either the ereros

>A

or !hallengeOres'onse 'roto!ols authenti!ate the user# Windows-integrated authenti!ation

re=uires that all users e running internet e'lorer A#1> or later ereros is a networauthenti!ation 'roto!ol# It is designed to 'roide strong authenti!ation "or !lientOserer

a''li!ations * using se!ret-e* !r*'togra'h*# ereros is a solution to networ se!urit*

'rolems# It 'roides the tools o" authenti!ation and strong !r*'togra'h* oer the networ

to hel' to se!ure in"ormation in s*stems a!ross entire enter'rise

Eass'ort authenti!ation

Eass'ort authenti!ation lets *ou to use Mi!roso"t8s 'ass'ort seri!e to authenti!ate users

o" *our a''li!ation# I" *our users hae signed u' with 'ass'ort, and *ou !on"igure the

authenti!ation mode o" the a''li!ation to the 'ass'ort authenti!ation, all authenti!ation

duties are o""-loaded to the 'ass'ort serers#

Eass'ort uses an en!r*'ted !ooie me!hanism to indi!ate authenti!ated users# I" users

hae alread* signed into 'ass'ort when the* isit *our site, the*8ll e !onsidered

authenti!ated * $SE#%&T#


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orms authenti!ation

orms authenti!ation 'roides *ou with a wa* to handle authenti!ation using *our own

!ustom logi! with in an $SE#%&T a''li!ation# The "ollowing a''lies i" *ou !hoose "orms

authenti!ation#

4 When a user re=uests a 'age "or the a''li!ation, $SE#%&T !he!s "or the

'resen!e o" a s'e!ial session !ooie# I" the !ooie is 'resent, $SE#%&T assumes

the user is authenti!ated and 'ro!esses the re=uest#

4 I" the !ooie isn8t 'resent, $SE#%&T redire!ts the user to a we "orm *ou

'roide

>0

Kou !an !arr* out whateer authenti!ation, !he!s *ou lie in *our "orm# When the user

is authenti!ated, *ou indi!ate this to $SE#%&T * setting a 'ro'ert*, whi!h !reates the

s'e!ial !ooie to handle suse=uent re=uests#

($)ow does authori7ation wor in $SE#%&T?

$SE#%&T im'ersonation is !ontrolled * entries in the a''li!ations we#!on"ig "ile# The

de"ault setting is 9no im'ersonation# Kou !an e'li!itl* s'e!i"* that $SE#%&T shouldn8tuse im'ersonation * in!luding the "ollowing !ode in the "ile

identit* im'ersonateV"alseOU

It means that $SE#%&T will not 'er"orm an* authenti!ation and runs with its own

'riileges# B* de"ault $SE#%&T runs as an un'riileged a!!ount named $SE%&T# Kou

!an !hange this * maing a setting in the 'ro!essModel se!tion o" the ma!hine#!on"ig

"ile# When *ou mae this setting, it automati!all* a''lies to eer* site on the serer# To

user a high-'riileged s*stem a!!ount instead o" a low-'riileged, set the user%ame

attriute o" the 'ro!essModel element to SKST&M# Gsing this setting is a de"inite se!urit*

ris, as it eleates the 'riileges o" the $SE#%&T 'ro!ess to a 'oint where it !an do ad

things to the o'erating s*stem#When *ou disale im'ersonation, all the re=uest will run in the !ontet o" the a!!ount

running $SE#%&T: either the $SE%&T a!!ount or the s*stem a!!ount# This is true when

*ou are using anon*mous a!!ess or authenti!ating users in some "ashion# $"ter the user

has een authenti!ated, $SE#%&T uses it own identit* to re=uest a!!ess to resour!es#

The se!ond 'ossile setting is to turn on im'ersonation#

identit* im'ersonate VtrueOU

In this !ase, $SE#%&T taes on the identit* IIS 'asses to it# I" *ou are allowing anon*mous

a!!ess in IIS, this means $SE#%&T will im'ersonate the IGS+QCom'uter%ame a!!ount

that IIS itsel" uses# I" *ou aren8t allowing anon*mous a!!ess,$SE#%&T will tae on the

!redentials o" the authenti!ated user and mae re=uests "or resour!es as i" it were that

user# Thus * turning im'ersonation on and using a non-anon*mous method o"

authenti!ation in IIS, *ou !an let users log on and use their identities within *our $SE#%&T

a''li!ation#

inall*, *ou !an s'e!i"* a 'arti!ular identit* to use "or all authenti!ated re=uests

identit* im'ersonateVtrue usernameV2


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With this setting, all the re=uests are made as the s'e!i"ied user ($ssuming the 'assword

it !orre!t in the !on"iguration "ile)# So, "or eam'le *ou !ould designate a user "or a single

a''li!ation, and use that user8s identit* eer* time someone authenti!ates to the

a''li!ation# The drawa! to this te!hni=ue is that *ou must emed the user8s 'assword

in the we#!on"ig "ile in 'lain tet# $lthough $SE#%&T won8t allow an*one to download

this "ile, this is still a se!urit* ris i" an*one !an get the "ile * other means#

(B)What8s di""eren!e etween 2atagrid , 2atalist and

re'eater ?

$ 2atagrid, 2atalist and +e'eater are all $SE#%&T data We !ontrols#

The* hae man* things in !ommon lie 2ataSour!e Ero'ert* , 2ataBind Method

Item2ataBound and ItemCreated#

When *ou assign the 2ataSour!e Ero'ert* o" a 2atagrid to a 2ataSet then ea!h 2ata+ow

'resent in the 2ata+ow Colle!tion o" 2ataTale is assigned to a !orres'onding

2ata5ridItem and this is same "or the rest o" the two !ontrols also#But The TML !ode

generated "or a 2atagrid has an TML T$BL& +


59/124

2ata5rid and 2ataList# B* re=uiring the deelo'er to s'e!i"* the !om'lete generated

TML maru', the +e'eater o"ten re=uires the longest deelo'ment time#But re'eater

does not 'roide editing "eatures lie datagrid so eer*thing has to e !oded * 'rogrammer

# oweer, the +e'eater does oast the est 'er"orman!e o" the three data We !ontrols#

+e'eater is "astest "ollowed * 2atalist and "inall* datagrid#

(B) 2i""eren!e etween $SE and $SE#%&T?

$SE#%&T new "eature su''orts are as "ollows :-

Better Language Su''ort

4 %ew $2


60/124

new re=uests to the new !ode#

($) What are ma6or eents in 5L


61/124

SessionQ&nd: ired when a userFs session times out, ends, or the* leae the a''li!ation

We site#

%ote :- 2uring interiew *ou do not hae to reall* !ram all these eents#But 6ust ee' the

asi! eents in mind

($) What order the* are triggered ?

The*Fre triggered in the "ollowing order:

$''li!ationQBegin+e=uest

$''li!ationQ$uthenti!ate+e=uest

$''li!ationQ$uthori7e+e=uest

$''li!ationQ+esole+e=uestCa!he

$''li!ationQ$!=uire+e=uestState

$''li!ationQEre+e=uestandler&e!ute

>A1

$''li!ationQEreSend+e=uesteaders

$''li!ationQEreSend+e=uestContent

!ode is ee!utedUU$''li!ationQEost+e=uestandler&e!ute

$''li!ationQ+elease+e=uestState

$''li!ationQG'date+e=uestCa!he

$''li!ationQ&nd+e=uest#

(I) 2o session use !ooies ?

Twist:- ow !an we mae session to not to use !ooies ?

Le"t to the user , *ou will en6o* to "ind this answer#

(I)ow !an we "or!e all the alidation !ontrol to run ?

Eage#.alidate

(B)ow !an we !he! i" all the alidation !ontrol are alidand 'ro'er ?

Gsing the Eage#Is.alid() 'ro'ert* *ou !an !he! whether all the alidation are done#

($)I" *ou hae !lient side alidation is enaled in *our We

'age , 2oes that mean serer side !ode is not run?

When !lient side alidation is enaled serer emit8s JaaS!ri't !ode "or the !ustom

alidators# But note that does not mean that serer side !he!s on !ustom alidators do

not ee!ute# It does this two time redundant !he!# $s some o" the alidators do not

su''ort !lient side s!ri'ting#

($)Whi!h JaaS!ri't "ile is re"eren!ed "or alidating the

alidators at the !lient side ?

>A>

WeGI.alidation#6s 6aas!ri't "ile installed at 9as'netQ!lient root IIS dire!tor* is used

to alidate the alidation !ontrols at the !lient side

(B)ow to disale !lient side s!ri't in alidators?

Set &naleClientS!ri't to "alse#

($)I want to show the entire alidation error message in a

message o on the !lient side?


62/124

In alidation summar* set 9ShowMessageBo to true#

(B)Kou "ind that one o" *our alidation is er* !om'li!ated

and does not "it in an* o" the alidators , so what will *ou do

?

Best is to go "or Custom.alidators##Below is a sam'le !ode "or a !ustom alidator whi!h

!he!s that a teto should not hae 7ero alue

as':Custom.alidator idVHCustom.alidator>H runatVHsererH

&rrorMessageVH%umer not diisile * ceroH

ControlTo.alidateVHtt%umerH


63/124

4 #as', "or $SE#%&T We 'ages,

4 #asm, "or $SE#%&T We seri!es,

4 #!on"ig, "or $SE#%&T !on"iguration "iles,

>AA

4 #ash, "or !ustom $SE#%&T TTE handlers,

4 #rem, "or remoting resour!es

4 &t!

Kou !an also !on"igure the etension ma''ing to whi!h engine it !an route * using the

IIS engine#

igure: - #> ollowing s!reen shows some IIS ma''ings

>A0

&am'le a $SE 'age will e sent to old !lassi! $SE#2LL to !om'ile# While #$SE 'ages

will e routed to $SE#%&T engine "or !om'ilation#

4 $s this oo mainl* will target $SE#%&T we will loo in to how $SE#%&T

'ages that is $SE 'ages generation se=uen!e o!!urs# #1#111#1,

CultureVneutral, Euli!e*ToenV1A""">>d1aAaH O

U

Ohtt'ModulesU

>A

The aoe ma''ing shows whi!h "un!tionalit* is handled * whi!h %ames'a!e# &am'le

orms$thuenti!ation is handled * 9S*stem#We#Se!urit*#orms$uthenti!ationModule#


64/124

I" *ou loo at the we#!on"ig se!tion TTE module is where authenti!ation and

authori7ation ha''ens#


65/124

elow "igure there are "ie 'ro!esses and eer* one handling indiidual a''li!ation# This

!onsumes hea* memor* ut has highest reliailit*#

>AD

igure: - # igh isolation s!enario

($)$SE used ST$ threading model , whats the threading

model used "or $SE#%&T ?

$SE#%&T uses MT$ threading model#

($)Whats the use o" _` 'age as'!om'atVtrue _U

attriute ?

This attriute wors lie a !om'atiilit* o'tion# $s said e"ore $SE wored in STS model

and $SE#%&T wors in MT$ model# But what i" *our $SE#%&T a''li!ation is using a

.B C01(B)&'lain the di""eren!es etween Serer-side and Clientside

!ode?

Serer side !ode is ee!uted at the serer side on IIS in $SE#%&T "ramewor , while

!lient side !ode is ee!uted on the rowser#

(I)Can *ou e'lain orms authenti!ation in detail ?

In old $SE i" *ou where said to !reate a login 'age and do authenti!ation *ou hae to do

hell lot o" !ustom !oding# But now in $SE#%&T that8s made eas* * introdu!ing orms

authenti!ation# So let8s see in detail what "orm authenti!ation is#

orms authenti!ation uses a ti!et !ooie to see that user is authenti!ated or not# That

means when user is authenti!ated "irst time a !ooie is set to tell that this user isauthenti!ated# I" the !ooies e'ire then orms authenti!ation me!hanism sends the user

to the login 'age#

ollowing are the ste's whi!h de"ines ste's "or orms authenti!ation :-

4 Con"igure We#!on"ig "ile with "orms authenti!ation#$s shown elow in the

!on"ig "ile *ou !an see we hae gie the !ooie name and loginurl 'age#

!on"igurationU

s*stem#weU

]--


66/124

>0>

4 +emoe anon*mous a!!ess to the IIS we a''li!ation , "ollowing are !hanges

done to we#!on"ig "ile#

!on"igurationU

s*stem#weU

]-- H runatVHsererH $utoEostBa!VHTrueH


67/124

9'rote!ted or 9'uli!

4 ollowing elow is the suroutine whi!h de"ines the method

Erote!ted Su Che!QCli!ed(B*.al sender $s 00

4 Kou !an oerride the "ollowing eents 'roided * seri!e and write *our

!ustom !ode# $ll the three main eents !an e used that is Start , sto' and

!ontinue#

'rote!ted oerride oid


68/124

Creational Eatterns

4 $stra!t a!tor*:- Creates an instan!e o" seeral "amilies o" !lasses

4 Builder :- Se'arates o6e!t !onstru!tion "rom its re'resentation

4 a!tor* Method:- Creates an instan!e o" seeral deried !lasses

4 Erotot*'e:- $ "ull* initiali7ed instan!e to e !o'ied or !loned

4 Singleton:- $ !lass o" whi!h onl* a single instan!e !an eist

%ote :- The est wa* to rememer Creational 'attern is * $BES ($raham Be!ame

irst Eresident o" States)#

Stru!tural Eatterns

4 $da'ter:-Mat!h inter"a!es o" di""erent !lasses#

4 Bridge:-Se'arates an o6e!t8s inter"a!e "rom its im'lementation#

4 Com'osite:-$ tree stru!ture o" sim'le and !om'osite o6e!ts#

4 2e!orator :-$dd res'onsiilities to o6e!ts d*nami!all*#

4 aade:-$ single !lass that re'resents an entire sus*stem#

4 l*weight:-$ "ine-grained instan!e used "or e""i!ient sharing#

4 Ero*:-$n o6e!t re'resenting another o6e!t#@##%&T $r!hite!ture

>03

%ote : To rememer stru!tural 'attern est is ($BC2E)

Behaioral Eatterns

4 Mediator:-2e"ines sim'li"ied !ommuni!ation etween !lasses#

4 Memento:-Ca'ture and restore an o6e!tFs internal state#

4 Inter'reter:-$ wa* to in!lude language elements in a 'rogram#

4 Iterator:-Se=uentiall* a!!ess the elements o" a !olle!tion#

4 Chain o" +es':-$ wa* o" 'assing a re=uest etween a !hain o" o6e!ts#

4 Command:-&n!a'sulate a !ommand re=uest as an o6e!t#4 State:-$lter an o6e!tFs ehaior when its state !hanges#

4 Strateg*:-&n!a'sulates an algorithm inside a !lass#

4


69/124

method to !om'lete the ar!hite!ture# $stra!t a!tor* is one leel higher in astra!tion

oer a!tor*#

>0

The elow two !lass diagrams will 'roide oeriew o" what the a!tual di""eren!e is#

irst "igure shows a sam'le im'lementation o" a!tor* Eatterns# In this "igure there are

two asi! se!tions:-

4 The a!tual 'rodu!t se!tion i#e# Class 9Erodu!t it inherits "rom a astra!t

!lass 9$stra!tErodu!t#

4 The !reational as'e!t se!tion that8s 9Con!reteCreator !lass whi!h inherits

"rom !lass 9Creator#

4 %ow there are some rules the !lient who will need the 9Erodu!t o6e!t will

"ollow# e will neer re"er dire!tl* to the a!tual 9Erodu!t o6e!t he will re"er

the 9Erodu!t o6e!t using 9$stra!tErodu!t#

4 Se!ond !lient will neer use 9%ew e*word to !reate the 9Erodu!t o6e!t

ut will use the 9Creator !lass whi!h in turn will use the 9Con!reteCreator

!lass to !reate the a!tual 9Erodu!t o6e!t#igure: - @#> Class diagram o" a "a!tor* Eattern

So what are ene"its "rom this ar!hite!ture? $ll !reational and initiali7ing as'e!ts are

now deta!hed "rom the a!tual !lient# $s *our !reational as'e!t is now een handled in

9Con!reteCreator and the !lient has re"eren!e to onl* 9Creator, so an* im'lementation

!hange in 9CreateErodu!t will not a""e!t the !lient !ode# In short now *ou !reational

as'e!t o" o6e!t is !om'letel* en!a'sulated "rom the !lient8s logi!#

%ow let8s loo at the se!ond !lass diagram whi!h 'roides an oeriew o" what a!tuall*

9$stra!t "a!tor* 'attern is# It !reates o6e!ts "or "amilies o" !lasses# In short it des!ries

!olle!tion o" "a!tor methods "rom arious di""erent "amilies# In short it grou's related

>0@"a!tor* methods# &am'le in this the !lass 9Creator is im'lemented using the 9$stra!t

"a!tor* 'attern# It now !reates o6e!ts "rom multi'le "amilies rather one 'rodu!t#

%ote :- Just sti! u' to this de"inition that $stra!t "a!tor* !lassi"ies "a!tor* methods or

grou's logi!all* related "a!tor* method together##

igure:- @# Class 2iagram o" $stra!t a!tor*

>0D

(I)What8s M.C 'attern?

Twist: - ow !an *ou im'lement M.C 'attern in $SE#%&T?

The main 'ur'ose using M.C 'attern is to de!ou'le the 5GI "rom the 2ata# It also gies

the ailit* to 'roide multi'le iews "or the same 2ata# M.C 'attern se'arates o6e!ts in

to three im'ortant se!tions:-

4 Model: - This se!tion is s'e!iall* "or maintaining data# It is a!tuall* where *our

usiness logi!, =uer*ing dataase, dataase !onne!tion et!# is a!tuall*

im'lemented#

4 .iews: - 2is'la*ing all or some 'ortion o" data, or 'roal* di""erent iew o"

data# .iew is res'onsile "or loo and "eel, Sorting, "ormatting et!#

4 Controller: - The* are eent handling se!tion whi!h a""e!ts either the model or


70/124

the iew# Controller res'onds to the mouse or e*oard in'ut to !ommand

model and iew to !hange# Controllers are asso!iated with iews# Gser

intera!tion triggers the eents to !hange the model, whi!h in turn !alls some

methods o" model to u'date its state to noti"* other registered iews to re"resh

their dis'la*#


71/124

a!tuall* does !hange on the main o6e!t itsel"# So how is dee' !o'* a!hieed, * using

9ISeriali7ale inter"a!e? So what *ou do is "irst seriali7e the o6e!t then deseriali7e a!

to a !om'lete new !o'*# %ow an* !hanges to this new !o'* do not re"le!t on the original

!o'* o" the o6e!t, this is !alled as 2ee' !o'*#

(I)What are the situations *ou will use a We Seri!e and +emoting in

'ro6e!ts?

Well 9We seri!es uses 9remoting !on!e'ts internall*# But the ma6or di""eren!e etween

9we seri!e and 9remoting is that 9we seri!e !an e !onsumed * !lients who are

not #%&T 'lat"orm# While remoting *ou need the !lient to e #%&T !om'liant# +egarding

the s'eed issue 9+emoting is "aster than 9We Seri!es# So I thin when de!iding the

ar!hite!ture side o" !hoosing etween 9We seri!es and 9+emoting ee' the !ross

'lat"orm issue and the s'eed issue in mind#

($)Can *ou gie a 'ra!ti!al im'lementation o" $f$2& 'atterns?

>

aade 'attern sits on the to' o" lot o" sus*stems and maes a!!ess eas* to inter"a!es

o" these sus*stems# Basi! 'ur'ose o" aade is to mae inter"a!ing etween man*modules and !lasses manageale#

igure: - @#0 aade in a!tion

$oe is a sim'le lie a''li!ation o" a aade !lass# In this we hae "our sus*stems :-

4 Customer

4 Erodu!t

>A

4 Ea*ment

4 Inoi!ing

$ll the "our modules when uilt at initial stage where uilt !om'letel* inde'endent# The

main intera!tion etween all these sus*stems is !ustomer 'la!ing order# This "un!tionalit*!an e attained * using all these sus*stems, whi!h inoles !om'le intera!tion etween

them#

There8s where $f$2& !omes in to a!tion# We hae uilt a $f$2& !alled as

9$C$2&


72/124

and dataase staging#

2ata $!!ess La*er: - This is also !alled * the "amous a!ron*m H2$LH !om'onent# It has

mainl* the S\L statement whi!h do the dataase o'eration 'art o" the 6o#

The three tier ar!hite!ture is used when an e""e!tie distriuted !lientOserer design is

needed that 'roides (when !om'ared to the two tier) in!reased 'er"orman!e, "leiilit*,

maintainailit*, reusailit*, and s!alailit*, while hiding the !om'leit* o" distriuted

'ro!essing "rom the user#

>0

(I)ae *ou eer wored with Mi!roso"t $''li!ation Blo!s, i" *es then

whi!h?

$''li!ation Blo!s are CN and .B#%&T !lasses distriuted as .isual Studio 'ro6e!ts

that !an e downloaded "rom Mi!roso"tFs We site and used in an* #%&T a''li!ation,

in!luding $SE#%&T We a''li!ations# The* are use"ul and 'ower"ul tools that !an mae

a''li!ations more maintainale, s!alale and e""i!ient

The se!ond =uestion whi!h o" the a''li!ation lo!s has een used de'ends on reall*

what *ou hae im'lemented# But there are two "amous M$B whi!h is maing u77 aroundthe industr*:-

4 data a!!ess lo!

The 2ata $!!ess Blo! 'roides stati! methods lo!ated in the S=lel'er !lass

that en!a'sulates the most !ommon data a!!ess tass 'er"ormed with Mi!roso"t

S\L serer# I" the term Hstati! methodH is new to *ou, it means that the !lass

methods !an e !alled without instantiating an instan!e o" the !lass# or

eam'le, the method &e!ute+eader () within the S=lel'er !lass !an e !alled

* sim'l* using the statement S=lel'er#&e!ute+eader () -- no o6e!t

instantiation o" the S=lel'er !lass is re=uired#

4 &!e'tion management lo!#The &!e'tion Management $''li!ation Blo! 'roides a sim'le *et etensile

"ramewor "or handling e!e'tions# With a single line o" a''li!ation !ode *ou

!an easil* log e!e'tion in"ormation to the &ent Log or etend it * !reating

*our own !om'onents that log e!e'tion details to other data sour!es or noti"*

o'erators, without a""e!ting *our a''li!ation !ode# The &!e'tion Management

$''li!ation Blo! !an easil* e used as a uilding lo! in *our own #%&T

a''li!ation

%ote: - It8s e*ond the s!o'e the oo to loo in to details o" a''li!ation lo!# Best is go to

www#mi!roso"t#!om and sear!h "or these a''li!ation lo!# Tr* to !om'ile one or two

'rograms using there gien !lasses and do!umentation#

($)What is Seri!e

inter"a!es o" these !om'onents# S


73/124

!rossing oundaries# Kou !an loo S3

igure: - @# S


74/124

The Windows 2istriuted inter%et $''li!ations $r!hite!ture (2%$) is a Mi!roso"t

lue'rint "or roust, s!alale, distriuted usiness so"tware# Windows 2%$ has eoled

oer time and was not 're'lanned# It gies all !omined adantages o" Centrali7ed

main"rame, a''li!ation serers, internet te!hnologies and Eersonal !om'uters# Windows

2%$ is a eolution whi!h started "rom main"rames (Where all logi! was !entrali7ed) ,

o 'ro ages ( Where we taled in terms o" two tier s*stems) , .B3 O S\L S&+.&+

(Three tier where we taled in terms o" haing one more tier whi!h was mainl* C@

where usiness logi! resided) , C


75/124

9$ !on!ern is a 'arti!ular goal, !on!e't, or area o" interest

There are mainl* two t*'es o" !on!ern "rom an o6e!t 'ers'e!tie:-

4 Core O Main !on!erns whi!h it should satis"* and is his wor#

I ho'e in m* se!ond edition i will !ome out with a se'erate !ha'ter on $31

4 S*stem !on!erns whi!h are not related to usiness "un!tionalities ut so"tware

related !on!erns eam'le audit trail, &rror handling, Se!urit* et!#

1 length (Business leel

!on!ern)

4 $ll !ustomer data whi!h is u'dated should e audited# (S*stem leel !on!ern)ere goes the !lass !ode# I" *ou see the ClsCustomer im'lementation in the u'date method

I hae !alled the $udit trail im'lementation# I" *ou reall* loo "rom o6e!t oriented 'oint

o" iew we are doing something in !ustomer !lass whi!h is su''osed to e not his

im'lementation: - $udit Trail logging# Thus we hae also roen down the rule o"

>3>

en!a'sulation# In short the !lass not onl* handles his wor ut also some other wor

whi!h is not his !on!ern#


76/124

5et

+eturn 'strCust%ame

&nd 5et

Set(B*.al .alue $s String)

>3

'strCust%ame V .alue

&nd Set

&nd Ero'ert*

Euli! un!tion G'date() $s Boolean

X "irst O !ore !on!ern

I" 'strCust!ode#Length() U >1 Then

Throw %ew &!e'tion(H.alue !an not e greater than >1H)

&nd I"

F usingthe !ustomer audit trail to do auditing

X se!ond !on!ern O s*stem !on!ern

2im 'o6Cls$uditTrail $s %ew Cls$uditTrailWith 'o6Cls$uditTrail

#%ew.alue V H>11>H

#11AH

#Gser%ame V HshiH

#G'date()

&nd With

F then inserting the !ustomer in dataase

&nd un!tion

&nd Class

Euli! Class Cls$uditTrailEriate 'strGser%ame $s String

Eriate 'str3A

Euli! Ero'ert* Gser%ame() $s String

5et

+eturn 'strGser%ame

&nd 5et


'strGser%ame V .alue

&nd Set

&nd Ero'ert*

Euli! Ero'ert*


77/124


'str30

5et

+eturn 'dlLogTime&nd 5et

Set(B*.al .alue $s 2oule)

'dlLogTime V .alue

&nd Set

&nd Ero'ert*

Euli! Su G'date()

F do the logging a!tiit* here

&nd Su

&nd Class

In short the !ustomer !lass is doing lot o" a!tiit*# There is lot o" tangling o" !ode# Sohow do we oer!ome this 'rolem Sim'le se'arate the S*stem leel !on!ern ($udit

Trail) "rom the !ore leel !on!ern ( Customer !ode !he!)# This is a!hieed at this

moment in #%&T using attriute 'rogramming#

ere is the !hange to the !ustomer !lass

Im'orts S*stem#+e"le!tion

Euli! Class ClsCustomer

Eriate 'strCust!ode $s String

Eriate 'strCust%ame $s String

Euli! Ero'ert* Code() $s String

5et

+eturn 'strCust!ode

&nd 5et


>3

'strCust!ode V .alue

&nd Set

&nd Ero'ert*


78/124

Euli! Ero'ert* Customer%ame() $s String

5et

+eturn 'strCust%ame

&nd 5et


'strCust%ame V .alue

&nd Set

&nd Ero'ert*

Cls$uditTrail(HShiH, H>11>H, H>11AH, >)U Q




&nd I"



&nd un!tion&nd Class

>33

$nd here is the !hange to the audit trail !lass

Im'orts S*stem#+e"le!tion

$ttriuteGsage($ttriuteTargets#$ll)U Q

Euli! Class Cls$uditTrail

Inherits $ttriute

Eriate 'strGser%ame $s String

Eriate 'str


79/124

&nd Ero'ert*

Euli! Ero'ert* %ew.alue() $s String

5et

+eturn 'str%ew.alue

&nd 5et


'str%ew.alue V .alue

&nd Set

&nd Ero'ert*

Euli! Ero'ert* LogTime() $s 2oule

5et

+eturn 'dlLogTime

&nd 5et

Set(B*.al .alue $s 2oule)

'dlLogTime V .alue

&nd Set&nd Ero'ert*

Euli! Su %ew(B*.al 'strGser%ame $s String, Q

B*.al 'str3@&nd Su

&nd Class

The "un 'art o" the !ode is elow , *ou !an see that the !ode audit trail is now se'erate

and the !ode !he! elongs to the !ustomer !ode#

Cls$uditTrail(HShiH, H>11>H, H>11AH, >)U Q




&nd I"



&nd un!tion

%ote:- $r!hite!ture is eer*od*s "aorite and the wide !omination is di""i!ult to e !oered

in this oo# Man* o" the things !an onl* !ome * lie e'erien!e#

$2


80/124

(B)What is the names'a!e in whi!h #%&T has the data

"un!tionalit* !lasses ?

ollowing are the names'a!es 'roided * #%&T "or data management :-

S*stem#data

This !ontains the asi! o6e!ts used "or a!!essing and storing relational data, su!h as

2ataSet,2ataTale, and 2ata+elation# &a!h o" these

Documents

dotnet faqs1