1.在布局中写上VideoView

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <VideoView
        android:id="@+id/video_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

2.activity中代码

    mMediaController = new MediaController(this);

    //我把文件写到缓存中了,FileIOUtils是blankj的
    //https://github.com/Blankj/AndroidUtilCode
    String cacheVideoPath = new File(getCacheDir(), "boot_animation.mp4").getPath();
    if (!FileUtils.isFileExists(cacheVideoPath)) {

        try {
            InputStream is = getResources().getAssets().open("boot_animation.mp4");//文件在assets下
            FileIOUtils.writeFileFromIS(cacheVideoPath, is);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    videoView.setVideoPath(cacheVideoPath);
    videoView.setMediaController(mMediaController);
    videoView.seekTo(0);
    videoView.requestFocus();
    videoView.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mediaPlayer) {
            doWork();//播放完我写了跳到其他页面
        }
    });
    videoView.start();

最近几天做的一个项目需要悬浮框,用popupwindow做的,用着好好的,前两天换了一下模拟器,今天突然发现不显示了,刚开始以为出现了什么异常,排查发现没有异常,bing了一下,原来是popupwindow不设置宽高在有些机型上会出现不显示的情况,其实是显示了,但是没有尺寸.

popup.setWidth(ViewGroup.LayoutParams.WRAP_CONTENT);
popup.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);

加上如上代码,好了,记录一下