AndroidUI system: ListView

AndroidUI system: ListView

1. Create a project: ListViewLearn

2. Modify MainActivity, inherited from ListActivity

3. Create a String array to save the actual content in ListView.

 
 

  
  
Package com. learn. listviewlearn. utility;
  
  
 
  
  
Public class Util {
  
  
Public static final String [] COUNTRYS = {"China", "USA", "Russia", "UK", "France "};
  
  
}
 
 

4. Modify the onCreate method and set an Adapter. The content in the array is displayed in ListView.

 
 

  
  
@Override 
  
  
  protected void onCreate(Bundle savedInstanceState) { 
  
  
      super.onCreate(savedInstanceState); 
  
  
      // setContentView(R.layout.activity_main); 
  
  
      this.setListAdapter(new ArrayAdapter<String>(this, 
  
  
              android.R.layout.simple_dropdown_item_1line, Util.COUNTRYS)); 
  
  
  } 

 
 

Ii. Use the XML layout file to define the ListView Style

1. Modify the activity_main.xml file and add a ListView. The id must be android: id = "@ android: id/list"

 
 

  
  
LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  
  
    android:layout_width="fill_parent" 
  
  
    android:layout_height="fill_parent" 
  
  
    android:orientation="vertical" > 
  
  
 
  
  
    <ListView 
  
  
        android:id="@android:id/list" 
  
  
        android:layout_width="fill_parent" 
  
  
        android:layout_height="fill_parent" 
  
  
        android:background="#FFFFFF00" > 
  
  
    </ListView> 
  
  
 
  
  
</LinearLayout> 
 
 

2. Modify the OnCreate Method

 
 

  
  
@Override 
  
  
  protected void onCreate(Bundle savedInstanceState) { 
  
  
      super.onCreate(savedInstanceState); 
  
  
      setContentView(R.layout.activity_main); 
  
  
      this.setListAdapter(new ArrayAdapter<String>(this, 
  
  
              android.R.layout.simple_dropdown_item_1line, Util.COUNTRYS)); 
  
  
  } 

 
 

3. Use an XML layout file to define the ListViewItem Style

1. Create a layout file list_view.xml

 
 

  
  
<?xml version="1.0" encoding="utf-8"?> 
  
  
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  
  
    android:layout_width="match_parent" 
  
  
    android:layout_height="match_parent" 
  
  
    android:orientation="horizontal" > 
  
  
 
  
  
    <ImageView 
  
  
        android:id="@+id/imageViewIcon" 
  
  
        android:layout_width="wrap_content" 
  
  
        android:layout_height="wrap_content" 
  
  
        android:contentDescription="@string/icon" > 
  
  
    </ImageView> 
  
  
 
  
  
    <TextView 
  
  
        android:id="@+id/textViewContent" 
  
  
        android:layout_width="wrap_content" 
  
  
        android:layout_height="wrap_content" > 
  
  
    </TextView> 
  
  
 
  
  
</LinearLayout> 
 
 

2. Create an Adapter that inherits from BaseAdapter and mainly modifies the getCount () and getView () methods.

 
 

  
  
package com.learn.listviewlearn.adapter; 
  
  
 
  
  
import com.learn.listviewlearn.R; 
  
  
import com.learn.listviewlearn.utility.Util; 
  
  
 
  
  
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 ListViewAdapter extends BaseAdapter { 
  
  
    private Context context; 
  
  
 
  
  
    public ListViewAdapter() { 
  
  
        // TODO Auto-generated constructor stub 
  
  
    } 
  
  
 
  
  
    @Override 
  
  
    public int getCount() { 
  
  
        return Util.COUNTRYS.length; 
  
  
    } 
  
  
 
  
  
    @Override 
  
  
    public Object getItem(int position) { 
  
  
        // TODO Auto-generated method stub 
  
  
        return null; 
  
  
    } 
  
  
 
  
  
    @Override 
  
  
    public long getItemId(int position) { 
  
  
        // TODO Auto-generated method stub 
  
  
        return 0; 
  
  
    } 
  
  
 
  
  
    @Override 
  
  
    public View getView(int position, View convertView, ViewGroup parent) { 
  
  
        if (convertView == null) { 
  
  
            convertView = LayoutInflater.from(context).inflate(R.layout.list_item, null); 
  
  
            ItemViewCache itemViewCache = new ItemViewCache(); 
  
  
            itemViewCache.imageView = (ImageView)convertView.findViewById(R.id.imageViewIcon); 
  
  
            itemViewCache.textView = (TextView)convertView.findViewById(R.id.textViewContent); 
  
  
            convertView.setTag(itemViewCache); 
  
  
        } 
  
  
         
  
  
        ItemViewCache cache = (ItemViewCache) convertView.getTag(); 
  
  
 
  
  
        cache.imageView.setImageResource(Util.images[position]); 
  
  
        cache.textView.setText(Util.COUNTRYS[position]); 
  
  
        return convertView; 
  
  
    } 
  
  
     
  
  
    private static class ItemViewCache{ 
  
  
        public TextView textView; 
  
  
        public ImageView imageView; 
  
  
    } 
  
  
 
  
  
} 
 
 

Util. java

 
 

  
  
Package com. learn. listviewlearn. utility;
  
  
 
  
  
Import com. learn. listviewlearn. R;
  
  
 
  
  
Public class Util {
  
  
Public static final String [] COUNTRYS = {"China", "USA", "Russia", "UK", "France "};
  
  
Public static final int [] images = {R. drawable. ic_launcher,
  
  
R. drawable. ic_launcher, R. drawable. ic_launcher,
  
  
R. drawable. ic_launcher, R. drawable. ic_launcher };
  
  
}

 
 

4. Add a Click event for the ListView. You only need to implement the onListItemClick () method in MainActivity.

 
 

  
  
@ Override
  
  
Protected void onListItemClick (ListView l, View v, int position, long id ){
  
  
Toast. makeText (this, "you selected" + Util. COUNTRYS [position], Toast. LENGTH_SHORT)
  
  
. Show ();
  
  
}
 
 

Link: http://www.cnblogs.com/zhangtingkuo/archive/2014/08/01/3884689.html