Upload
cvikasgupta
View
220
Download
0
Embed Size (px)
Citation preview
8/12/2019 Additional Web Server Controls
1/25
Chapter 4The Additional WebServer Controls
8/12/2019 Additional Web Server Controls
2/25
2 Additional Server ControlsOverview
This presentation briefly discusses theadditional web server controls
8/12/2019 Additional Web Server Controls
3/25
3 Additional Server ControlsThe Additional Controls
These controls are less frequently usedthan those covered in the previouschapter.
they are still quite useful to know.
The controls covered in this chapter can begrouped into two categories:
those that are container controls
those that are not.
8/12/2019 Additional Web Server Controls
4/25
4 Additional Server ControlsThe Additional Controls
The Panel , Mul t i Vi ewand Vi ew, Wi zar d,and Pl aceHol der controls' basic functionis to act as a container or parent for othercontrols.
These container controls have manypowerful features that make them animportant part of any ASP.NET developersrepertoire.
The other controls covered in this chapter(AdRot at or , Fi l eUpl oad, and Xmlcontrols) are not container controls.
They perform fairly specialized jobs and assuch may not be used nearly as frequentlyas some other controls.
8/12/2019 Additional Web Server Controls
5/25
5 Additional Server ControlsList of the Other Web Server
Controls
Displays a check box for selectedtrue or false values.
Panel
The MultiView control is a container
for groups of View controls.
Mul t i Vi ew,
Vi ew
Displays a push button that posts aWeb form page back to the server.Allows a user to upload a file to theserver. Consists of a text box andBrowse button.
Fi l eUpl oad
Displays an advertisement banner(i.e., a randomly selected imagethat, when clicked, navigates to anew Web page).
AdRot at or
8/12/2019 Additional Web Server Controls
6/25
6 Additional Server ControlsList of the Other Web Server
Controls
Displays an XML file or the results ofan XSLT (Extensible Stylesheet
Language Transformation)transformation.
Xml
Provides a series of interconnectedforms used for collectinginformation incrementally from theuser.
Wi zar d
A container control used fordynamically loading other controls.
Pl aceHol der
8/12/2019 Additional Web Server Controls
7/25
7 Additional Server ControlsPanel Control
The Panel control is a container controlthat can be used as a parent container forplain text, HTML elements, and other webserver controls.
The Panel control is typically used forcreating group behavior, e.g.
creating a unique look for an area on apage
programmatically display and hide groupsof controls.
8/12/2019 Additional Web Server Controls
8/25
8 Additional Server ControlsPanel Control
Panel
Panel
(Hidden)
Panel
(Visible)
8/12/2019 Additional Web Server Controls
9/25
9 Additional Server ControlsMultiView + View
Like the Panel control the Mul t i Vi ewcontrol is a container control for othercontent and controls.
The Mul t i Vi ewcontrol is a container for
groups of Vi ewcontrols. Each of these Vi ewcontrols is also a
container for other controls and HTMLcontent.
They are an easier way to selectivelydisplay and hide groups of controls thanusing multiple Panel controls.
Often no programming is required.
8/12/2019 Additional Web Server Controls
10/25
8/12/2019 Additional Web Server Controls
11/25
11 Additional Server ControlsWeb Wizards
Web applications often require some typeof wizard-style interface that leads the userthrough a series of step-by-step forms.
A wizard is thus used to retrieve
information from the user via a series ofdiscrete steps.
each step in the wizard asks the user toenter some subset of information.
8/12/2019 Additional Web Server Controls
12/25
12 Additional Server ControlsWeb Wizard
8/12/2019 Additional Web Server Controls
13/25
13 Additional Server ControlsWeb Wizards
In regular Windows applications, wizardstend to be modal in that the user can notdo any other processing while the wizard isactive:
the user can only move forward,backwards, finish, or possibly jump to someother step in the wizard.
As well, Windows-based wizards arepipelines,
i.e., a wizard is a chain of processes inwhich there is only one entrance and wherethe output of each step in the process is theinput to the next step.
8/12/2019 Additional Web Server Controls
14/25
14 Additional Server ControlsWeb Wizards
Implementing wizards in web applicationsposes several problems.
A Windows application can strictly controlhow a wizard is launched, and can easily
ensure users start and exit the wizard in theappropriate way.
This is much harder to implement in a webenvironment.
A user could, for instance, bookmark an
intermediate step in the wizard and try toreturn to it at some point in the future.
A web-based wizard must thus be able tomaintain the pipeline nature of the wizardand ensure that the user only ever starts
the wizard at the first step.
8/12/2019 Additional Web Server Controls
15/25
15 Additional Server ControlsWeb Wizards
Maintaining state information in a multi-page web wizard can also be tricky.
Since the intent of a wizard is to gatherinformation from the user in a series of
discrete steps, a web wizard needs to beable to pass information gathered inprevious steps onto the next step.
This requires repetitive coding for theretrieval and verification of the previous
steps data. As well, there is typically a great deal of
repetitive code for the handling ofnavigation within the wizard.
8/12/2019 Additional Web Server Controls
16/25
16 Additional Server ControlsWizard Control
The Wi zar d control in ASP.NET 2.0 makesthe process of creating a web wizardsignificantly easier.
This control provides a simpler mechanism
for building steps, adding new steps, orreordering the steps.
The Wi zar d control eliminates the need tomanage the persistence of your data
across pages because the control itselfmaintains state while the user completesthe various steps.
8/12/2019 Additional Web Server Controls
17/25
17 Additional Server ControlsWizard Control
St ep One
Emai l
Passwor d
St ep Two
Shi ppi ng
Ai r Mai l Fed Ex
8/12/2019 Additional Web Server Controls
18/25
18 Additional Server ControlsWizard Styling
You have a great deal of control over theappearance and behavior of the Wi zar dcontrol.
8/12/2019 Additional Web Server Controls
19/25
19 Additional Server ControlsFileUpload Control
The Fi l eUpl oad control provides amechanism for users to send a file fromtheir computer to the server.
The control is rendered in the browser as a
Text Box control and a But t on control.
8/12/2019 Additional Web Server Controls
20/25
20 Additional Server ControlsPlaceHolder Control
The Pl acehol der web server controlenables you to dynamically add servercontrols to a page at run-time.
The Pl acehol der is an empty container
control with no HTML rendering on itsown.
instead, the control renders any childelements it contains.
8/12/2019 Additional Web Server Controls
21/25
21 Additional Server ControlsPlaceHolder Control
There are many situations in which itmight make sense to add a controldynamically at run-time rather thanstatically at design-time.
A portal application, for instance, mayconsist of only a few pages, each containingPl acehol der controls that are loaded withthe appropriate server and user controls atrun-time according to some algorithm or
some content in a database.
8/12/2019 Additional Web Server Controls
22/25
22 Additional Server ControlsAdRotator Control
Displays a randomly selectedadvertisement banner (a graphic image).
The displayed advertisement can changewhenever the page refreshes.
If a user clicks the ad, he or she isredirected to the target URL specified bythe control.
The displayed advertisements can also be
priority weighted; this allows certainadvertisements to be displayed more often.
The control works by readingadvertisement information stored in aseparate data source, which is usually anXML file.
8/12/2019 Additional Web Server Controls
23/25
23 Additional Server ControlsXml Control
The Xml server control can be used todisplay the unformatted contents of anXML document or the result of an XSLTtransformation.
8/12/2019 Additional Web Server Controls
24/25
24 Additional Server ControlsXSLT
An XSLT document is itself an XMLdocument.
It is an XML-based programming languagefor transforming XML documents.
The .NET XSLT parser can thus be used totransform a XML document into an XMLdocument with a different structure, aHTML file, a text file, or almost any othertype of document.
8/12/2019 Additional Web Server Controls
25/25
25 Additional Server ControlsXML Control + XSLT
Xml control in the browser with no XSLT
Xml control using an XSLT file