作者丨7_pxhttps://www.jianshu.com/p/fc5cf284abbb
壁纸运行在一个Android办事之中，这个办事的名字叫做WallpaperService。当用户选择了一个壁纸之后，此壁纸所对应的WallpaperService便会启动并起头进行壁纸的绘制工作。
Engine是WallpaperService中的一个内部类，实现了壁纸窗口的建立以及Surface的维护工作。Engine内部实现了SurfaceView，我们只需要在其内部行使MediaPlayer + SurfaceView就能够播放动态壁纸了。
WallpaperService需要一个xml去设置，然后在AndroidManifest.xml中声明
android:thumbnail=”@mipmap/icon_lacation_black___cm”>
继续WallpaperService实现我们本身的壁纸办事VideoLiveWallpaper
public class VideoLiveWallpaper extends WallpaperService{
@Override
public Engine onCreateEngine(){
return new VideoEngine();
}
class VideoEngine extends Engine{
private MediaPlayer mMediaPlayer;
@Override
public void onCreate(SurfaceHolder surfaceHolder){
super.onCreate(surfaceHolder);
}
@Override
public void onDestroy(){
super.onDestroy();
}
@Override
public void onSurfaceCreated(SurfaceHolder holder){
super.onSurfaceCreated(holder);
mMediaPlayer = new MediaPlayer();
mMediaPlayer.setSurface(holder.getSurface());
try {
mMediaPlayer.setDataSource(new File(FileUtil.getDCIMCameraDir(), “hlj_wallpaper”).getAbsolutePath());
mMediaPlayer.setLooping(true);
mMediaPlayer.setVolume(0, 0);
mMediaPlayer.prepare();
mMediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp){
mMediaPlayer.start();
}
});
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void onSurfaceDestroyed(SurfaceHolder holder){
super.onSurfaceDestroyed(holder);
mMediaPlayer.release();
mMediaPlayer = null;
}
@Override
public void onVisibilityChanged(boolean visible){
if (visible) {
mMediaPlayer.start();
} else {
mMediaPlayer.pause();
}
}
}
}
接着声明这个办事同时声明我们上面写的xml设置
android:name=”.VideoLiveWallpaper”
android:label=”@string/app_name”
android:permission=”android.permission.BIND_WALLPAPER”
android:process=”:wallpaper”>
android:name=”android.service.wallpaper”
android:resource=”@xml/wallpaper” />
重点在onSurfaceCreated方式中，这里为了能够动态切换分歧的壁纸，我是指定去加载一个固定目录下的视频文件，然后络续的复制新文件到这个目录，因为一旦开启切换壁纸这个方式就会挪用，所以当挪用后再动态通知去更改路径不起感化。
所以我在更调壁纸前先清空
try {
WallpaperManager.getInstance(getContext())
.clear();
} catch (IOException e) {
e.printStackTrace();
}
再去复制需要替代的壁纸到指定目录
copyFile(file.getAbsolutePath(),
new File(FileUtil.getDCIMCameraDir(),
“hlj_wallpaper”).getAbsolutePath());
/**
* 复制单个文件
*
* @param oldPath String 原文件路径 如：c:/fqf.txt
* @param newPath String 复制后路径 如：f:/fqf.txt
* @return boolean
*/
public void copyFile(final String oldPath, final String newPath){
progressBar.setVisibility(View.VISIBLE);
Observable.create(new Observable.OnSubscribe() {
@Override
public void call(Subscriber super Boolean> subscriber){
try {
int byteSum = 0;
int byteRead ;
File oldFile = new File(oldPath);
if (oldFile.exists()) { //文件存在时
InputStream inStream = new FileInputStream(oldPath); //读入原文件
FileOutputStream fs = new FileOutputStream(newPath);
byte[] buffer = new byte[1444];
while ((byteRead = inStream.read(buffer)) != -1) {
byteSum += byteRead; //字节数 文件巨细
System.out.println(byteSum);
fs.write(buffer, 0, byteRead);
}
inStream.close();
subscriber.onNext(true);
subscriber.onCompleted();
}
} catch (Exception e) {
System.out.println(“复制单个文件把持失足”);
e.printStackTrace();
subscriber.onCompleted();
}
}
})
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Observer() {
@Override
public void onCompleted(){
progressBar.setVisibility(View.GONE);
}
@Override
public void onError(Throwable e){
progressBar.setVisibility(View.GONE);
}
@Override
public void onNext(Boolean aBoolean){
progressBar.setVisibility(View.GONE);
setToWallPaper(getContext());
}
});
}
setToWallPaper 方式就是真正的开启设置壁纸把持了
public static void setToWallPaper(Context context){
final Intent intent = new Intent(WallpaperManager.ACTION_CHANGE_LIVE_WALLPAPER);
intent.putExtra(WallpaperManager.EXTRA_LIVE_WALLPAPER_COMPONENT,
new ComponentName(context, VideoLiveWallpaper.class));
context.startActivity(intent);
}
至此，一个简洁的动态壁纸就搞定了。
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