android - 最小化android中以前 Activity 中的 Activity

Question

我正在开发一个支持即时消息的视频通话组件。我想添加在按下后最小化视频通话屏幕的选项，并返回到消息传递 activity 以同时执行这两项操作(类似 WhatsApp 的功能)。问题是，我找不到解决方案，因为返回到上一个 activity 将完成当前 Activity 。那么我该如何覆盖我的onBackpressed()，这样我就可以最小化而不是完成调用屏幕activity(假设将其添加到通知中) 并返回消息传递 activity?

Answer 1

你想做的叫做Picture-in-Picture .

Android 8.0 (API level 26) allows activities to launch in picture-in-picture (PIP) mode. PIP is a special type of multi-window mode mostly used for video playback. It lets the user watch a video in a small window pinned to a corner of the screen while navigating between apps or browsing content on the main screen.

一个非常简单的例子:

1) 在您的 AndroidManifest 文件中指定支持 PIP 的 Activity:

<activity
      android:name=".VideoActivity"
      android:configChanges="screenSize|smallestScreenSize|screenLayout|orientation"
      android:resizeableActivity="true"
      android:supportsPictureInPicture="true"/>

2) 触发 PIP 模式以响应某些用户操作，例如在 onBackPressed() 中:

override fun onBackPressed() {
   // Ideally you would want to enter PIP while a video is playing, so:
   val isVideoPlaying = // have a condition here that holds true while the video is playing

   if (isVideoPlaying) {
        enterPictureInPictureMode()
   } else {
        super.onBackPressed()
   }
}