Android中的动画详解系列【2】——飞舞的蝴蝶

<?xml version="1.0" encoding="utf-8"?>
<!-- 定义动画循环播放 -->
<animation-list xmlns:android="http://schemas.android.com/apk/res/android"
android:oneshot="false">
<item android:drawable="@drawable/butterfly_f01" android:duration="120" />
<item android:drawable="@drawable/butterfly_f02" android:duration="120" />
<item android:drawable="@drawable/butterfly_f03" android:duration="120" />
<item android:drawable="@drawable/butterfly_f04" android:duration="120" />
<item android:drawable="@drawable/butterfly_f05" android:duration="120" />
<item android:drawable="@drawable/butterfly_f06" android:duration="120" />
</animation-list>

<?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:background="@drawable/background"
>
<ImageView
android:id="@+id/butterfly"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@anim/butteryfly"
/>
</LinearLayout>

package com.example.butteryfly;

import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.graphics.drawable.AnimationDrawable;
import android.os.Bundle;
import android.os.Handler;
import android.view.Display;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.TranslateAnimation;
import android.widget.ImageView;

public class MainActivity extends Activity {

private float curX = 0;
private float curY = 30;

private float nextX = 0;
private float nextY = 0;

private int windowW = 0;
private int windowH = 0;

private ImageView imageView;

Handler handler = new Handler(){
public void handleMessage(android.os.Message msg) {
if(msg.what == 0x123){
if(nextX > windowW || nextY > windowH){
curX = nextX = 0;
}else{
nextX += 8;
}

nextY = curY + (float) (Math.random() * 20 - 10);
TranslateAnimation anim = new TranslateAnimation(curX, nextX, curY, nextY);
curX = nextX;
curY = nextY;
anim.setDuration(200);
imageView.startAnimation(anim);
}
};
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

imageView = (ImageView) findViewById(R.id.butterfly);

Display display = getWindowManager().getDefaultDisplay();
windowW = display.getWidth();
windowH = display.getHeight();

final AnimationDrawable butterfly = (AnimationDrawable) imageView.getBackground();
imageView.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
butterfly.start();
new Timer().schedule(new TimerTask() {

@Override
public void run() {
handler.sendEmptyMessage(0x123);
}
}, 0, 200);
}
});
}
}