Android多媒体播放功能的代码分析

import android.app.Activity; 
import android.os.Bundle;
  import android.view.View;
  import android.view.View.OnClickListener; 
import android.widget.Button;
  import android.widget.VideoView; 
public class VideoPlayer extends Activity   {
  /**   Called when the activity is first created.
  */
@Override
  public void onCreate(Bundle icicle)   {
  super.onCreate(icicle);
  setContentView(R.layout.main);
  final VideoView w =(VideoView)findViewById(R.id.vdoplayer);
  Button cmdload = (Button)this.findViewById(R.id.cmd_load);   cmdload.setOnClickListener(new OnClickListener()  { 
public void onClick(View arg0)   {  
// TODO Auto-generated method stub
  w.setVideoPath("/sdcard/android/kongfu.mp4");
  } 
} 
); 
Button cmdplay = (Button)this.findViewById(R.id.cmd_play); 
cmdplay.setOnClickListener(new OnClickListener()  {  
public void onClick(View arg0)   { 
// TODO Auto-generated method stub 
w.start(); 
}
  } 
);  
Button cmdpause = (Button)this.findViewById(R.id.cmd_pause);   cmdpause.setOnClickListener(new OnClickListener()  {
  public void onClick(View arg0)   {
  // TODO Auto-generated method stub
  w.pause(); 
}
  }
  );
  }

< ?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" >
< Button android:id="@+id/cmd_load"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="load" />
< Button android:id="@+id/cmd_play"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Play" />
< Button android:id="@+id/cmd_pause"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="pause" />
< VideoView android:id="@+id/vdoplayer"
android:layout_width="fill_parent"
android:layout_height="300px" />
< /LinearLayout>