package tk.pixilab.android;
 
import java.util.Random;
 
import android.app.Activity;
import android.graphics.drawable.AnimationDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
 
public class CoinActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
 
        final Drawable kopf = (Drawable)getResources().getDrawable(R.drawable.coin_1);
        final Drawable zahl = (Drawable)getResources().getDrawable(R.drawable.coin_5);
        final AnimationDrawable animation = (AnimationDrawable)getResources().getDrawable(R.drawable.coin_animation);
        final Button btn_coin = (Button)findViewById(R.id.main_btn_coin);
        btn_coin.setOnClickListener(new OnClickListener() {
 
			@Override
			public void onClick(View v) {
				int random = animation.isRunning()?new Random().nextInt(2):2;
				switch(random) {
					case 0:{
						animation.stop();
						btn_coin.setBackgroundDrawable(kopf);
						break;
					}
					case 1:{
						animation.stop();
						btn_coin.setBackgroundDrawable(zahl);
						break;
					}
					case 2:{
						btn_coin.setBackgroundDrawable(animation);
						animation.start();
						break;
					}
				}
 
			}
		});
    }
}

<?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"
    android:gravity="center"
    android:background="@drawable/background"
    >
<Button
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:id="@+id/main_btn_coin"
	android:background="@drawable/coin_1"/>
</LinearLayout>

<?xml version="1.0" encoding="UTF-8"?>
<bitmap xmlns:android="http://schemas.android.com/apk/res/android" android:src="@drawable/background_img" android:tileMode="repeat"/>

<?xml version="1.0" encoding="UTF-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android" android:oneshot="false">
	<item android:drawable="@drawable/coin_1" android:duration="50" />
	<item android:drawable="@drawable/coin_2" android:duration="50" />
	<item android:drawable="@drawable/coin_3" android:duration="50" />
	<item android:drawable="@drawable/coin_4" android:duration="50" />
	<item android:drawable="@drawable/coin_5" android:duration="50" />
	<item android:drawable="@drawable/coin_6" android:duration="50" />
	<item android:drawable="@drawable/coin_7" android:duration="50" />
	<item android:drawable="@drawable/coin_8" android:duration="50" />
</animation-list>