Android编程实现动画自动播放功能

private ImageView image;
private AnimationDrawable animDrawable = new AnimationDrawable();
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.table_title);
    image = (ImageView) this.findViewById(R.id.scrollView);
    //代码实现
//   for(int i=0; i<16; i++){
//     int id = getResources().getIdentifier("load_"+(i+1), "drawable", getPackageName());
//     animDrawable.addFrame(getResources().getDrawable(id), 50);
//   }
//   animDrawable.setOneShot(false);
//   image.setBackgroundDrawable(animDrawable);
    animDrawable = (AnimationDrawable) image.getBackground();
}
@Override
public void onWindowFocusChanged(boolean hasFocus) {
    super.onWindowFocusChanged(hasFocus);
    animDrawable.start();
}

AnimationDrawable ad;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    ImageView iv = (ImageView) findViewById(R.id.animation_view);
    iv.setBackgroundResource(R.drawable.animation);
    ad = (AnimationDrawable) iv.getBackground();
   //关键代码
   iv.getViewTreeObserver().addOnPreDrawListener(opdl);
}
OnPreDrawListener opdl=new OnPreDrawListener(){
    @Override
    public boolean onPreDraw() {
        if(ad.isRunning() == false){
        ad.start();
        }
        return true; //注意必须返回true
    }
};