Fragment Communication in android

7/24/2019 Fragment Communication in android

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Communication b/w Fragments

Fragment is a peace of Activity in android.

One Activity can have any no.of fragments. Each fragment have it's own

functionality.

All the fragmnets must be existed in one or more than one activity. Without

activity we can't show the fragment in android application.

Two frgments should never communicate directly.

The control of android fragmentis handled by the activity which is havingthe fragment.

The lifecycle of fragment is purely depends on activity lifecycle which is

contains that fragment.

!sing fragments we can utili"e the device screen for multiple functionalities

shows at the same time.

#n this Android Tutorialwe learn about how communicate two fragmentswithin the same activity. For Example i have one activity that activity display two

differnet fragments. #n first fragment # will show the list of districts and in my

second fragment #t will display the details of individual district. when tap on first

fragment district list.

$reate new Android Application pro%ect.

activity_main.xml

&inearayout

xmlns(android)*http(++schemas.android.com+ap,+res+android*

xmlns(tools)*http(++schemas.android.com+tools*

android(layout-width)*match-parent*
http://www.pcnmtutorialsc.com/http://www.pcnmtutorialsc.com/


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android(layout-height)*match-parent*

android(orientation)*hori"ontal*

android(baselineAligned)*false*

&fragment

android(id)*/0id+listOfEmployees*

android(name)*com.example.fragmentcommunication.fragments.istOfEmployeesF

ragment*

android(layout-width)*1dp*

android(layout-height)*fill-parent*

android(layout-weight)*2*+

&fragment

android(id)*/0id+employee3etais*

android(name)*com.example.fragmentcommunication.fragments.Employee3etailsF

ragment*

android(layout-width)*1dp*


android(layout-weight)*4*+

&+inearayout

The name attribute is indicates fragment class in your android application.

andrid:laout_weightThis is the attribute to align the fragments in android

activity. if you give layout-weight as 2 then it is first fragment it will show leftside

fo your screen. #f you give layout-weight as 4 then it will show as second part in

your activity. #t will show rightside of your screen.

5ow crete a new layout for list of 3istricts. This is the fragment in your

android activity. The layout name is fragment_list_fragment.xml

&6xml version)*2.1* encoding)*utf78*6


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&inearayout

android(id)*/0id+listOfdists*


android(layout-width)*fill-parent*


&ist9iew

android(id)*/0id+list*



&+ist9iew

&+inearayout

5ow crete another new layout for display individual district details. This is the

fragment in your android activity. The layout name is

fragment_details_fragment.xml

&6xml version)*2.1* encoding)*utf78*6

&inearayout


android(id)*/0id+details*



android(orientation)*vertical*

&Text9iew

android(id)*/0id+details9iew*

android(layout-width)*fill-parent*

android(layout-height)*wrap-content*+


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&+inearayout

5ow create we need to create three two more classes for two fragment.

The first fragment is ListFragment.java. This fragment displays the list of

employees. And the second class is second fragment in our android application.

That class name is DetailsFragment.java.

$opy below code into your ListFragment.javaclass in your android

application pro%ect.

import %ava.util.Arrayist:

import %ava.util.ist:

import android.app.Activity:

import android.os.;undle:

import android.support.v


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>

private 9iew v:

private static ist9iew lvOne:

private ist&?tring listOf3istricts:

private ArrayAdapter&?tring adapter:

ist#tem?electedistener itemisterner:

/Override

public 9iew on$reate9iew@ayout#nflater inflater 9iew=roup container

;undle saved#nstance?tate

>

inflater )

@ayout#[email protected][email protected]!T-#5FATEC-?EC9#$E:

v ) [email protected] null false:

addist#temsToist9iew@:

initiali"eisteners@:

return v:

D

/Override

public void onAttach@Activity activity

>


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super.onAttach@activity:

itemisterner ) @ist#tem?electedisteneractivity:

D

private void addist#temsToist9iew@

>

lvOne ) @ist9iewv.find9iew;y#[email protected]:

listOf3istricts ) new Arrayist&?tring@:

listOf3istricts.add@*?ri,a,ulam*:

listOf3istricts.add@*9i%ayanagaram*:

listOf3istricts.add@*9i"ag*:

adapter ) new ArrayAdapter&?tring@getActivity@

android.C.layout.simple-list-item-2 listOf3istricts:

lvOne.setAdapter@adapter:

D

private void initiali"eisteners@

>

lvOne.setOn#tem$lic,istener@this:

D

public interface ist#tem?electedistener

>


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public void list#tem?electedistener@?tring name:

D

/Override

public void on#tem$lic,@Adapter9iew&6 parent 9iew view int position long id

>

itemisterner.list#[email protected]@position:

D

D

#n the above fragment we are use one Interfaceis

calledistItem!electedistener. ;ecause We can not communicate directly two

fragments in android if you want communicate two fragemnts. we need to create

one interface in first Fragment and implement that interfac in Activity of that

fragment. And then create one public setter method in second Fragement and

assign the appropriate value to second fragment by using that public method.

itemisterner " #istItem!electedistener$activity%This peace of line

indicates the interface listerner register with the actiivty.

itemisterner.listItem!electedistener#list&f'istricts.get#(osition$$%

This peace of code indicates the value set as a perameter to method of interface.

when implent the interface into activity. Then you must override this method in

Activity register for this fragment.

5ow create a new class with name 'etailsFragment.)ava#n this class it will

display the related content. ;ased on selected items in the first fragment. The

below code snippet is copy into your class.

DetailsFragment.java

pac,age com.example.fragmentcommunication:


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import android.content.$ontext:



private static Text9iew tvOne:

private 9iew v:

$ontext context:

private static final ?tring TA= ) *3etailsFragment*:

public void get#tem9alue@?tring item5ame $ontext context

>

this.context ) context:

tvOne.setText@*Welcome to ( *0item5ame:

D

/Override

public 9iew on$reate9iew@ayout#nflater inflater 9iew=roup container

;undle saved#nstance?tate

>

inflater )

@ayout#[email protected]?ystem?ervice@[email protected]!T-#5FATEC-?E

C9#$E:


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v ) [email protected] null false:

tvOne ) @Text9iewv.find9iew;y#[email protected]:

on$reate@saved#nstance?tate:

return v:

D

D

#n the above code snippet we are write one method (ublic void

getItem*alue#!tring item+ame, Context context$. The usage of this method

is to assign the selected value in the first fragment to second fragment using

activity.

5ow $oming to -ainActivity.)avawe will implement the interface. which is

declared in first fragment and assign the value getting from first activity and send it

to second fragment. ?o copy the below code snippet into-ainActivity.)ava

pac,age com.example.fragmentcommunication:

import

com.example.fragmentcommunication.istFragment.ist#tem?electedistener:



public static final ?tring TA= ) *ainActiviyt*:

/Override

protected void on$reate@;undle saved#nstance?tate >

super.on$reate@saved#nstance?tate:

try

>


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[email protected]:

D

catch@Exception e

>

og.e@TA= e.to?tring@:

D

D

/Override

public void list#tem?electedistener@?tring name

>

3etailsFragment detailsFragment ) new 3etailsFragment@:

detailsFragment.get#tem9alue@name this:

D

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Fragment Communication in android