Android ListView实现简单列表功能

package fry;

import com.example.ListView.R;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class Activity01 extends Activity implements OnItemClickListener{
 private ListView listView;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  // TODO Auto-generated method stub
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity01);
  listView=(ListView) findViewById(R.id.listView);
  ArrayAdapter<String  adapter=new ArrayAdapter<String (this, android.R.layout.simple_expandable_list_item_1, getData());
  listView.setAdapter(adapter);
  listView.setOnItemClickListener(this);
 }
 @Override
 public void onItemClick(AdapterView<?  parent, View view, int position,
   long id) {
  // TODO Auto-generated method stub
  String string=(String) parent.getItemAtPosition(position);
  
  Toast.makeText(this, string, Toast.LENGTH_SHORT).show();
 }
 
 private String[] getData(){
  return new String[]{"韩寒","蔡静","卢本伟","五五开","战狼2","朝阳兄","虹桥一姐","犀利哥","王宝庆",
    "系大大","搞踹踹","张三","李四","王五"};
 }
}

<?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="vertical"  

 <ListView 
  android:id="@+id/listView"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
   </ListView 

</LinearLayout