//使用WallpaperManager類
    @TargetApi(Build.VERSION_CODES.N)
    private Bitmap getLockWallpaper(){
        WallpaperManager wallpaperManager = WallpaperManager.getInstance(this);//獲取WallpaperManager實(shí)例
        ParcelFileDescriptor mParcelFileDescriptor = wallpaperManager.getWallpaperFile(WallpaperManager.FLAG_LOCK);//獲取鎖屏壁紙
        if(mParcelFileDescriptor ==null){
            mParcelFileDescriptor = wallpaperManager.getWallpaperFile(WallpaperManager.FLAG_SYSTEM);//獲取桌面壁紙
            //在未主動(dòng)設(shè)置鎖屏壁紙時(shí)，鎖屏壁紙為null，默認(rèn)取的是桌面壁紙，
        }
        FileDescriptor fileDescriptor = mParcelFileDescriptor.getFileDescriptor();
        Bitmap image = BitmapFactory.decodeFileDescriptor(fileDescriptor);//獲取Bitmap類型返回值
        try {
            mParcelFileDescriptor.close();
        } catch(Exception e) {
            android.util.Log.d("TAG","mParcelFileDescriptor.close() error");
        }
        return image;
    }

    private void setBackground(){ // 獲取壁紙后設(shè)置為view的背景
        try {
            Drawable drawable =new BitmapDrawable(getLockWallpaper());//將Bitmap類型轉(zhuǎn)換為Drawable類型
            getWindow().getDecorView().setBackgroundDrawable(drawable);//設(shè)置背景
            drawable.setColorFilter(Color.GRAY, PorterDuff.Mode.MULTIPLY);//設(shè)置背景灰度
        } catch(Exception e) {
            android.util.Log.d("TAG","set Background fail");
        }
    }