<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android"
android:oneshot="false"
>
    <item
        android:drawable="@mipmap/ani_1"
        android:duration="800" />
    <item
        android:drawable="@mipmap/ani_2"
        android:duration="800" />
    <item
        android:drawable="@mipmap/ani_3"
        android:duration="800" />
    <item
        android:drawable="@mipmap/ani_4"
        android:duration="800" />
    <item
        android:drawable="@mipmap/ani_5"
        android:duration="800" />
    <item
        android:drawable="@mipmap/ani_6"
        android:duration="800" />
    <item
        android:drawable="@mipmap/ani_7"
        android:duration="800" />
    <item
        android:drawable="@mipmap/ani_8"
        android:duration="800" />
</animation-list>

public class MainActivity extends AppCompatActivity {
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		ImageView lImageView = findViewById(R.id.imageview);
		//設(shè)置圖片
		lImageView.setImageResource(R.drawable.loading);
		//動
		AnimationDrawable lAnimationDrawable = (AnimationDrawable) lImageView.getDrawable();
		
		lAnimationDrawable.start();
		
	}
}

ViewTreeObserver.OnPreDrawListener lOnPreDrawListener=new ViewTreeObserver.OnPreDrawListener(){
	@Override
	public boolean onPreDraw() {
		lAnimationDrawable.start();
		return true; //注意此行返回的值
	}
};

//綁定視圖觀察者
lImageView.getViewTreeObserver().addOnPreDrawListener(lOnPreDrawListener);

public class MainActivity extends AppCompatActivity {
	

	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		start3();
	}

	private AnimationDrawable mAnimationDrawable;
	
	public void start3() {
		ImageView lImageView = findViewById(R.id.imageview);
		//設(shè)置圖片
		lImageView.setImageResource(R.drawable.loading);
		//動
		mAnimationDrawable = (AnimationDrawable) lImageView.getDrawable();
		
		RunAnim runAnim = new RunAnim();
		runAnim.execute("");
		
		
	}
	
	class RunAnim extends AsyncTask<String, String, String> {
		@Override
		protected String doInBackground(String... params) {
			if (!mAnimationDrawable.isRunning()) {
				mAnimationDrawable.stop();
				mAnimationDrawable.start();
			}
			return "";
		}
	}
}

@Override
public void onWindowFocusChanged(boolean hasFocus)
{
	mAnimationDrawable.start();
	super.onWindowFocusChanged(hasFocus);
}