receiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { if (intent != null && intent.getAction().equals(Intent.ACTION_CLOSE_SYSTEM_DIALOGS)) { String reason = intent.getStringExtra("reason"); if (!reason.isEmpty() && (reason.equals("homekey") || reason.equals("recentapps"))) { // Android8.0开始才提供画中画模式 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O && !isInPictureInPictureMode()) { PictureInPictureParams.Builder builder = new PictureInPictureParams.Builder(); // 设置宽高比例值，第一个参数表示分子，第二个参数表示分母 // 下面的10/5=2，表示画中画窗口的宽度是高度的两倍 Rational ratio = new Rational(10, 5); builder.setAspectRatio(ratio); // 进入画中画模式 enterPictureInPictureMode(builder.build()); } } } } };