Android动态壁纸的制作教程.docx

动态壁纸是在Android 2.1新增的一个功能。动态壁纸可以添加到Android的桌面，具有交互式的动画背景效果。在本教程中，我们将教会你如何去制作一个交互式的动态壁纸。动态壁纸是一个Android应用程序，包括一个服务(WallpaperService)。该服务必须包括一个引擎(WallpaperService.Engine)。该引擎是连接用户、桌面、系统之间的桥梁。它也可以绘制桌面壁纸。首先，必须由内在的Engine类创建一个WallpaperService类。该服务必须在AndroidManifest.xml中声明为android.service.wallpaper.WallpaperService，这样它才会作为动态壁纸被手机识别。而且还要在服务配置中附加android.permission.BIND_WALLPAPER的权限许可：?12345678910111213创建一个XML文件，放置在应用程序目录下的/res/xml/中。它用来描述你的动态壁纸。?123456再创建一个xml的属性文件attrs.xml，代码如下：?1234567891011121314动态壁纸的服务代码如下：?123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105package net.androgames.blog.sample.livewallpaper;import android.content.SharedPreferences;import android.service.wallpaper.WallpaperService;import android.view.MotionEvent;import android.view.SurfaceHolder;/* Android Live Wallpaper Archetype* author antoine vianey* under GPL v3 : /licenses/gpl-3.0.html*/public class LiveWallpaperService extends WallpaperService Overridepublic Engine onCreateEngine() return new SampleEngine();Overridepublic void onCreate() super.onCreate();Overridepublic void onDestroy() super.onDestroy();public class SampleEngine extends Engine private LiveWallpaperPainting painting;SampleEngine() SurfaceHolder holder = getSurfaceHolder();painting = new LiveWallpaperPainting(holder, getApplicationContext();Overridepublic void onCreate(SurfaceHolder surfaceHolder) super.onCreate(surfaceHolder);/ register listeners and callbacks heresetTouchEventsEnabled(true);Overridepublic void onDestroy() super.onDestroy();/ remove listeners and callbacks herepainting.stopPainting();Overridepublic void onVisibilityChanged(boolean visible) if (visible) / register listeners and callbacks herepainting.resumePainting(); else / remove listeners and callbacks herepainting.pausePainting();Overridepublic void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) super.onSurfaceChanged(holder, format, width, height);painting.setSurfaceSize(width, height);Overridepublic void onSurfaceCreated(SurfaceHolder holder) super.onSurfaceCreated(holder);/ start paintingpainting.start();Overridepublic void onSurfaceDestroyed(SurfaceHolder holder) super.onSurfaceDestroyed(holder);boolean retry = true;painting.stopPainting();while (retry) try painting.join();retry = false; catch (InterruptedException e) Overridepublic void onOffsetsChanged(float xOffset, float yOffset, float xStep, float yStep, int xPixels, int yPixels) Overridepublic void onTouchEvent(MotionEvent event) super.onTouchEvent(event);painting.doTouchEvent(event);当壁纸的显示、状态或大小变化是，会调用Engine的onCreate,onDestroy,onVisibilityChanged,onSurfaceChanged,onSurfaceCreated和onSurfaceDestroyed方法。有了这些方法，动态壁纸才能展现出动画效果。而通过设置setTouchEventsEnabled（true），并且调用onTouchEvent（MotionEvent event）方法，来激活触摸事件。我们在绘画墙纸的时候，也会使用一个单独的绘画线程：?123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140package net.androgames.blog.sample.livewallpaper;import android.content.Context;import android.graphics.Canvas;import android.view.MotionEvent;import android.view.SurfaceHolder;/* Android Live Wallpaper painting thread Archetype* author antoine vianey* GPL v3 : /licenses/gpl-3.0.html*/public class LiveWallpaperPainting extends Thread /* Reference to the View and the context */private SurfaceHolder surfaceHolder;private Context context;/* State */private boolean wait;private boolean run;/* Dimensions */private int width;private int height;/* Time tracking */private long previousTime;private long currentTime;public LiveWallpaperPainting(SurfaceHolder surfaceHolder, Context context) / keep a reference of the context and the surface/ the context is needed if you want to inflate/ some resources from your livewallpaper .apkthis.surfaceHolder = surfaceHolder;this.context = context;/ dont animate until surface is created and displayedthis.wait = true;/* Pauses the live wallpaper animation*/public void pausePainting() this.wait = true;synchronized(this) this.notify();/* Resume the live wallpaper animation*/public void resumePainting() this.wait = false;synchronized(this) this.notify();/* Stop the live wallpaper animation*/public void stopPainting() this.run = false;synchronized(this) this.notify();Overridepublic void run() this.run = true;Canvas c = null;while (run) try c = this.surfaceHolder.lockCanvas(null);synchronized (this.surfaceHolder) currentTime = System.currentTimeMillis();updatePhysics();doDraw(c);previousTime = currentTime; finally if (c != null) this.surfaceHolder.unlockCanvasAndPost(c);/ pause if no need to animatesynchronized (this) if (wait) try wait(); catch (Exception e) /* Invoke when the surface dimension change*/public void setSurfaceSize(int width, int height) this.width = width;this.height = height;synchronized(this) this.notify();/* Invoke while the screen is touched*/public void doTouchEvent(MotionEvent event) / handle the event here/ if there is something to animate/ then wake upthis.wait = false;synchronized(this) notify();/* Do the actual drawing stuff*/private void doDraw(Canvas canvas) /* Update the animatio