Details about complex functions of Android ListView

 

------------------------------------------- Activity_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">

<ListView
Android: id = "@ android: id/list"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"

>
</ListView>

</RelativeLayout> list_item.xml <? Xml version = "1.0" encoding = "UTF-8"?>
<LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content">

<TextView
Android: id = "@ + id/item_text"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: layout_marginLeft = "10dp"
Android: textSize = "16sp"
Android: layout_weight = "1"
Android: textStyle = "bold"/>

<ImageView
Android: id = "@ + id/item_right"

Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"/>

<ImageView
Android: id = "@ + id/item_right1"

Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"/>

</LinearLayout>

 

 

 

------------------------------------------. Main
Package com. example. tezt;

Import java. util. ArrayList;
Import java. util. HashMap;
Import java. util. List;
Import java. util. Map;

Import android. app. ListActivity;
Import android. OS. Bundle;
Import android. view. Menu;

Public class MainActivity extends
ListActivity {

@ Override
Public void onCreate (
Bundle savedInstanceState ){
Super. onCreate (savedInstanceState );
SetContentView (R. layout. activity_main );

List <Map <String, Object> datas = getDatas ();
ImageAdapter adapter = new ImageAdapter (
This, datas );

This. getListView (). setAdapter (
Adapter );
}

Private List <Map <String, Object> getDatas (){
// TODO Auto-generated method stub
List <Map <String, Object> results = new ArrayList <Map <String, Object> ();
String [] items = this
. GetResources ()
. GetStringArray (
R. array. menu );

For (int I = 0; I <items. length; I ++ ){
Map <String, Object> item = new HashMap <String, Object> ();
Item. put ("right1 ",
R. drawable. icon2 );
Item. put ("text", items [I]);
Item. put ("right ",
R. drawable. icon1 );

Results. add (item );
}

Return results;

}

@ Override
Public boolean onCreateOptionsMenu (
Menu menu ){
GetMenuInflater (). inflate (
R. menu. activity_main,
Menu );
Return true;
}
}

 

 

 

-------------------------------------------. ImageAdapter

Package com. example. tezt;

Import java. util. List;
Import java. util. Map;

Import android. content. Context;
Import android. view. LayoutInflater;
Import android. view. View;
Import android. view. ViewGroup;
Import android. widget. BaseAdapter;
Import android. widget. ImageView;
Import android. widget. TextView;

Public class ImageAdapter extends
BaseAdapter {
Private List <Map <String, Object> datas;

Private Context context;

Public ImageAdapter (
Context context,
List <Map <String, Object> datas ){
This. context = context;
This. datas = datas;
}

@ Override
Public int getCount (){
// TODO Auto-generated method stub
Return this. datas. size ();
}

@ Override
Public Object getItem (int position ){
// TODO Auto-generated method stub
Return this. datas. get (position );
}

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

@ Override
Public View getView (int position,
View convertView,
ViewGroup parent ){
// TODO Auto-generated method stub
ViewHolder holder = null;

If (convertView = null ){
Holder = new ViewHolder ();
ConvertView = LayoutInflater
. From (context)
. Inflate (
R. layout. list_item,
Null );
Holder. itemRightImage1 = (ImageView) convertView
. FindViewById (R. id. item_right1 );
Holder. itemText = (TextView) convertView
. FindViewById (R. id. item_text );
Holder. itemRightImage = (ImageView) convertView
. FindViewById (R. id. item_right );

ConvertView. setTag (holder );
}
Else {
Holder = (ViewHolder) convertView
. GetTag ();
}

Map <String, Object> item = this. datas
. Get (position );

Holder. itemRightImage1
. SetImageResource (Integer
. ParseInt (item
. Get ("right1 ")
. ToString ()));
Holder. itemText
. SetText (item. get (
"Text ")
. ToString ());
Holder. itemRightImage
. SetImageResource (Integer
. ParseInt (item
. Get ("right ")
. ToString ()));

Return convertView;
}

Static class ViewHolder {
ImageView itemRightImage1;
TextView itemText;
ImageView itemRightImage;
}