改变imageButton按下和抬起时的background图片

public class MainActivity extends Activity {
02 
03     private ImageButton ibtn;
04     @Override
05     protected void onCreate(Bundle savedInstanceState) {
06         super.onCreate(savedInstanceState);
07         setContentView(R.layout.activity_main);
08         ibtn = (ImageButton) findViewById(R.id.imgbtn);
09         ibtn.setOnTouchListener(new OnTouchListener() {
10             //为图片添加触屏监听，
11             @Override
12             public boolean onTouch(View arg0, MotionEvent event) {
13                 //用户当前为按下
14                 if(event.getAction()==MotionEvent.ACTION_DOWN){
15                     //设置图片按钮背景图
16                     ibtn.setBackgroundDrawable(getResources().getDrawable(R.drawable.press));
17                     //用户当前为抬起
18                 }else if(event.getAction()==MotionEvent.ACTION_UP){
19                     ibtn.setBackgroundDrawable(getResources().getDrawable(R.drawable.nopress));
20                 }
21                 return false;
22             }
23         });
24     }
25 
34 }