Android control development-ExpandableListActivity (2): android custom control

Android control development-ExpandableListActivity (2): android custom control
Android control development-ExpandableListActivity (2)This blog post describes how to use ExpandableListActivity to create a friend list similar to QQ. Let's look at the implementation code.This instance contains an Activity and a master layout file. Other level-1 and level-2 directories are implemented by rewriting the getGroupView () and getChildView () methods in ExpandableListActivity.

The MainActivity. java code is as follows:This Activity is mainly an extends self-ListActivity class,
Package com. example. expandablelistactivity;


Import java. util. ArrayList;
Import java. util. HashMap;
Import android. OS. Bundle;
Import android. app. ListActivity;
Import android. database. DataSetObserver;
Import android. graphics. Color;
Import android. view. Gravity;
Import android. view. Menu;
Import android. view. View;
Import android. view. ViewGroup;
Import android. widget. AbsListView;
Import android. widget. ExpandableListAdapter;
Import android. widget. ExpandableListView;
Import android. widget. ImageView;
Import android. widget. LinearLayout;
Import android. widget. SimpleExpandableListAdapter;
Import android. widget. ExpandableListView. OnChildClickListener;
Import android. widget. TextView;

/*It is mainly implemented by rewriting related methods in ExpandableListAdapter ().*/

Public class MainActivity extends ListActivity {


@ Override
Protected void onCreate (Bundle savedInstanceState ){
Super. onCreate (savedInstanceState );
SetContentView (R. layout. main );

// Anonymous internal class, override the ExpandableListAdapter Class Method
Final ExpandableListAdapter ela = new ExpandableListAdapter (){
// Set the Group view image
Int [] logos = new int [] {R. drawable. ic_launcher, R. drawable. ic_launcher, R. drawable. ic_launcher };
// Set the display text of the Group view
Private String [] generalsTypes = new String [] {"group1", "group2 "};
// Display text in the subview
Private String [] [] generals = new String [] [] {
{"Child1data1", "child1data2", "child1data3 "},
{"Child2data1 "}


};
// Subview Image
Public int [] [] generallogos = new int [] [] {
{R. drawable. list1, R. drawable. list2,
R. drawable. list3 },
{R. drawable. list4 }};

// Define a method for obtaining text information
TextView getTextView (){
// Set the height and width of textView
AbsListView. LayoutParams lp = new AbsListView. LayoutParams (
ViewGroup. LayoutParams. FILL_PARENT, ViewGroup. LayoutParams. WRAP_CONTENT );
TextView textView = new TextView (
MainActivity. this );
TextView. setLayoutParams (lp );
TextView. setGravity (Gravity. CENTER_VERTICAL );
TextView. setPadding (10, 10, 10, 10 );
TextView. setTextSize (15 );
TextView. setTextColor (Color. BLACK );
Return textView;
}



// Override each method in the ExpandableListAdapter
@ Override
Public int getGroupCount (){
// TODO Auto-generated method stub
Return generalsTypes. length;
}


@ Override
Public Object getGroup (int groupPosition ){
// TODO Auto-generated method stub
Return generalsTypes [groupPosition];
}


@ Override
Public long getGroupId (int groupPosition ){
// TODO Auto-generated method stub
Return groupPosition;
}


@ Override
Public int getChildrenCount (int groupPosition ){
// TODO Auto-generated method stub
Return generals [groupPosition]. length;
}


@ Override
Public Object getChild (int groupPosition, int childPosition ){
// TODO Auto-generated method stub
Return generals [groupPosition] [childPosition];
}


@ Override
Public long getChildId (int groupPosition, int childPosition ){
// TODO Auto-generated method stub
Return childPosition;
}


@ Override
Public boolean hasStableIds (){
// TODO Auto-generated method stub
Return true;
}


@ Override
Public View getGroupView (int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent ){
// TODO Auto-generated method stub
// Create a LinearLayout View
LinearLayout ll = new LinearLayout (
MainActivity. this );
Ll. setOrientation (0 );

// Create an ImageView object
ImageView logo = new ImageView (MainActivity. this );
Logo. setImageResource (logos [groupPosition]);
Logo. setPadding (50, 0, 0, 0 );
// Add an ImageView in LinearLayout
Ll. addView (logo );

// Create a TextView object
TextView textView = getTextView ();
TextView. setTextColor (Color. BLACK );
TextView. setText (getGroup (groupPosition). toString ());
// Add TextView to LinearLayout
Ll. addView (textView );


Return ll;
}


@ Override
Public View getChildView (int groupPosition, int childPosition,
Boolean isLastChild, View convertView, ViewGroup parent ){
// TODO Auto-generated method stub
// Create a LinearLayout object
LinearLayout ll = new LinearLayout (
MainActivity. this );
Ll. setOrientation (0 );

// Create an ImageView object
ImageView generallogo = new ImageView (
MainActivity. this );
Generallogo. setImageResource (generallogos [groupPosition] [childPosition]);
Generallogo. setPadding (5, 5, 5, 5 );

// Add the imageView object to the LinearLayout object
Ll. addView (generallogo );

// Create a TextView object
TextView textView = getTextView ();
TextView. setText (getChild (groupPosition, childPosition)
. ToString ());

Ll. addView (textView );
Return ll;
}


@ Override
Public boolean isChildSelectable (int groupPosition,
Int childPosition ){
// TODO Auto-generated method stub
Return true;
}




@ Override
Public boolean areAllItemsEnabled (){
// TODO Auto-generated method stub
Return false;
}






@ Override
Public long getCombinedChildId (long groupId, long childId ){
// TODO Auto-generated method stub
Return 0;
}




@ Override
Public long getCombinedGroupId (long groupId ){
// TODO Auto-generated method stub
Return 0;
}




@ Override
Public boolean isEmpty (){
// TODO Auto-generated method stub
Return false;
}




@ Override
Public void onGroupCollapsed (int groupPosition ){
// TODO Auto-generated method stub

}




@ Override
Public void onGroupExpanded (int groupPosition ){
// TODO Auto-generated method stub

}




@ Override
Public void registerDataSetObserver (DataSetObserver observer ){
// TODO Auto-generated method stub

}


@ Override
Public void unregisterDataSetObserver (DataSetObserver observer ){
// TODO Auto-generated method stub

}};


// Set simpleexpandablelistview to the expandablelistadapter
ExpandableListView expandableListView = (ExpandableListView) findViewById (android. R. id. list );
ExpandableListView. setAdapter (ela );


// Bind the listener of ExpandableListView child
ExpandableListView. setOnChildClickListener (new expandableChildLisenter ());

}

// Implement the second-level menu listener
Class expandableChildLisenter implements OnChildClickListener {


@ Override
Public boolean onChildClick (ExpandableListView parent, View v,
Int groupPosition, int childPosition, long id ){
// TODO Auto-generated method stub
System. out. println ("group =" + groupPosition );
System. out. println ("child =" + childPosition );
System. out. println ("id =" + id );

Return false;
}

}

@ Override
Public boolean onCreateOptionsMenu (Menu menu ){
// Inflate the menu; this adds items to the action bar if it is present.
GetMenuInflater (). inflate (R. menu. main, menu );
Return true;
}


}



Main. xml:
<RelativeLayout xmlns: android = "http://schemas.android.com/apk/res/android"
Xmlns: tools = "http://schemas.android.com/tools"
Android: layout_width = "match_parent"
Android: layout_height = "match_parent"
Android: paddingBottom = "@ dimen/activity_vertical_margin"
Android: paddingLeft = "@ dimen/activity_horizontal_margin"
Android: paddingRight = "@ dimen/activity_horizontal_margin"
Android: paddingTop = "@ dimen/activity_vertical_margin"
Tools: context = ". MainActivity">


<TextView
Android: id = "@ + id/myText"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: text = "@ string/hello_world"/>

<! -- Set the layout file of the ExpandableListView main interface -->
<ExpandableListView
Android: id = "@ id/android: list"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"
Android: padding = "5dp"
Android: layout_below = "@ id/myText"
> </ExpandableListView>


</RelativeLayout>

The image resources used include:R. drawable. list1R. drawable. list2R. drawable. list3R. drawable. list4R. drawable. ic_launcher
The implementation result is as follows: