Basic use of the ExpandableListView control in Android

 

This article uses a Demo to show how to use the ExpandableListView control in Android, such as how to bind a data source to a group or sublistview. The Code is as follows:

 

Program structure:

 

 

The source code of the main. xml file in the layout directory is as follows:

 

 

<? Xml version = "1.0" encoding = "UTF-8"?>

<LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"

Android: orientation = "vertical"

Android: layout_width = "fill_parent"

Android: layout_height = "fill_parent">

<! -- We will define the display mode of the listview (in another layout file) by ourselves without the default mode.

If you customize the display mode of listview, this android: id = "@ id/android: list" must be written like this -->

<! -- Android: drawSelectOnTop = "false" This attribute is used to set whether the background color on the listview is

Block (overwrite) content. If this parameter is set to false, the content will not be overwritten. -->

<ExpandableListView

Android: id = "@ id/android: list"

Android: layout_width = "fill_parent"

Android: layout_height = "wrap_content"

Android: layout_weight = "1"

Android: drawselectid Top = "false"/>

</LinearLayout>

 

The source code of ContactsActivity. java in package com. andyidea. demo is as follows:

 

 

Package com. andyidea. demo;

 

Import java. util. ArrayList;

Import java. util. List;

 

Import android. app. ExpandableListActivity;

Import android. OS. Bundle;

Import android. view. Gravity;

Import android. view. View;

Import android. view. ViewGroup;

Import android. view. Window;

Import android. widget. AbsListView;

Import android. widget. BaseExpandableListAdapter;

Import android. widget. TextView;

 

Public class ContactsActivity extends ExpandableListActivity {

List <String> group; // group List

List <String> child; // sublist

ContactsInfoAdapter adapter; // data adapter

/** Called when the activity is first created .*/

@ Override

Public void onCreate (Bundle savedInstanceState ){

Super. onCreate (savedInstanceState );

RequestWindowFeature (Window. FEATURE_NO_TITLE); // set it to Untitled.

SetContentView (R. layout. main );

GetExpandableListView (). setBackgroundResource (R. drawable. default_bg );

InitializeData ();

GetExpandableListView (). setAdapter (new ContactsInfoAdapter ());

GetExpandableListView (). setCacheColorHint (0); // sets the black background when dragging the list.

}

/**

* Initialize group and sublist data

*/

Private void initializeData (){

Group = new ArrayList <String> ();

Child = new ArrayList <List <String> ();

AddInfo ("Andy", new String [] {"male", "138123 ***", "GuangZhou "});

AddInfo ("Fairy", new String [] {"female", "138123 ***", "GuangZhou "});

AddInfo ("Jerry", new String [] {"male", "138123 ***", "ShenZhen "});

AddInfo ("Tom", new String [] {"female", "138123 ***", "ShangHai "});

AddInfo ("Bill", new String [] {"male", "138231 ***", "ZhanJiang "});

}

/**

* Simulate adding data to a group or sublist

* @ Param g-group

* @ Param c-child

*/

Private void addInfo (String g, String [] c ){

Group. add (g );

List <String> childitem = new ArrayList <String> ();

For (int I = 0; I <c. length; I ++ ){

Childitem. add (c [I]);

}

Child. add (childitem );

}

Class ContactsInfoAdapter extends BaseExpandableListAdapter {

 

// ----------------- Child ----------------//

@ Override

Public Object getChild (int groupPosition, int childPosition ){

Return child. get (groupPosition). get (childPosition );

}

@ Override

Public long getChildId (int groupPosition, int childPosition ){

Return childPosition;

}

@ Override

Public int getChildrenCount (int groupPosition ){

Return child. get (groupPosition). size ();

}

@ Override

Public View getChildView (int groupPosition, int childPosition,

Boolean isLastChild, View convertView, ViewGroup parent ){

String string = child. get (groupPosition). get (childPosition );

Return getGenericView (string );

}

// ---------------- Group ----------------//

@ Override

Public Object getGroup (int groupPosition ){

Return group. get (groupPosition );

}

 

@ Override

Public long getGroupId (int groupPosition ){

Return groupPosition;

}

@ Override

Public int getGroupCount (){

Return group. size ();

}

@ Override

Public View getGroupView (int groupPosition, boolean isExpanded,

View convertView, ViewGroup parent ){

String string = group. get (groupPosition );

Return getGenericView (string );

}

 

// Create a group/subview

Public TextView getGenericView (String s ){

// Layout parameters for the ExpandableListView

AbsListView. LayoutParams lp = new AbsListView. LayoutParams (

ViewGroup. LayoutParams. FILL_PARENT, 40 );

TextView text = new TextView (ContactsActivity. this );

Text. setLayoutParams (lp );

// Center the text vertically

Text. setGravity (Gravity. CENTER_VERTICAL | Gravity. LEFT );

// Set the text starting position

Text. setPadding (36, 0, 0, 0 );

Text. setText (s );

Return text;

}

@ Override

Public boolean hasStableIds (){

// TODO Auto-generated method stub

Return false;

}

 

@ Override

Public boolean isChildSelectable (int groupPosition, int childPosition ){

// TODO Auto-generated method stub

Return true;

}

}

}

 

Finally, the program runs as follows:

 

From: Android-Idea