Android設定桌面主要用到了WallPaperService這個類。首先建立自己的類繼承WallPaperService並重寫onCreateEngine()方法，建立自己的Engine。

 1、建立自己的Engine類GifEngine 繼承Engine，重寫裡面的onSurfaceCreated方法，onVisibilityChanged方法，onSurfaceDestroy方法。在onSurfaceCreate方法中載入gif動畫，這裡涉及到gif動畫的載入與播放，涉及到Movie類，用movie解碼gif檔案然後畫在canvas上，並重復一幀一幀的繪製。這樣就能將gif動畫渲染到surfaceView上呈現到螢幕。

   onVisibilityChanged方法在桌面可見不可見的時候進行回撥，當螢幕可見的時候進行播放，螢幕不可見取消gif繪製。onSurfaceDestroy銷燬的時候銷燬操作。類如下：

public class GIfWallPaperService extends WallpaperService {
    private Movie movie;
    private Handler handler;
    private boolean isVisible;
    private int height;
    private int width;
    private int 
 
gifWidth;
    private int gifHeigth;
@Override
public Engine onCreateEngine() {
        return new GifEngine();
}


    class GifEngine extends Engine {

        @Override
public void onSurfaceCreated(SurfaceHolder holder) {
            super.onSurfaceCreated(holder);
handler = new Handler();
            try 
 
{
                InputStream inputStream = getContentResolver().openInputStream(Config.filePath);movie = Movie.decodeStream(inputStream);
DisplayMetrics displayMetrics = getResources().getDisplayMetrics();
height = displayMetrics.heightPixels;
width = displayMetrics.widthPixels;
gifWidth = movie.width();
gifHeigth = movie.height();
} catch (FileNotFoundException e) {
                e.printStackTrace();
}
        }

        @Override
public void onVisibilityChanged(boolean visible) {
            if (visible) {
                isVisible = true;
handler.post(runnable);
} else {
                isVisible = false;
handler.removeCallbacks(runnable);
}

        }

        @Override
public void onSurfaceDestroyed(SurfaceHolder holder) {
            super.onSurfaceDestroyed(holder);
handler.removeCallbacks(runnable);
}private Runnable runnable = new Runnable() {
            @Override
public void run() {
                if (isVisible) {Canvas canvas = getSurfaceHolder().lockCanvas();canvas.save();
canvas.scale(2 , 2 );movie.draw(canvas, 0, 0);movie.setTime((int) (System.currentTimeMillis() % movie.duration()));
canvas.restore();getSurfaceHolder().unlockCanvasAndPost(canvas);
handler.postDelayed(runnable, 50);   //50ms表示每50m繪製一次
}
            }
        };
}
}

2、配置AndroidMainfest.xml 

<service android:name=".service.GIfWallPaperService"
android:label="@string/gif_wallpaper"
android:permission="android.permission.BIND_WALLPAPER">
    <intent-filter>
        <action android:name="android.service.wallpaper.WallpaperService" />
    </intent-filter>
    <meta-data
android:name="android.service.wallpaper"

      android:resource="@xml/gif_wallpaper" />

</service>

3、配置gif_wallpaper.xml

<?xml version="1.0" encoding="utf-8"?><wallpaper xmlns:android="http://schemas.android.com/apk/res/android"
android:thumbnail="@mipmap/ic_launcher"
android:description="@string/gif_description"
/>

4、配置strings.xml

<string name="gif_description">gif動態桌布</string>

5、配置許可權

<uses-permission android:name="android.permission.SET_WALLPAPER" />

6、啟動GifService

Intent intent = new Intent(WallpaperManager.ACTION_CHANGE_LIVE_WALLPAPER);
intent.putExtra(WallpaperManager.EXTRA_LIVE_WALLPAPER_COMPONENT,new ComponentName(context, GIfWallPaperService.class));
startActivity(intent);