import com.google.vr.sdk.widgets.video.VrVideoEventListener; //导入依赖的package包/类
@Override
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_cardboard);

  final Toolbar toolbar = findViewById(R.id.toolbar);
  setSupportActionBar(toolbar);
  getSupportActionBar().setDisplayHomeAsUpEnabled(true);

  progress = findViewById(R.id.progress);
  errorDialog = ErrorDialog.newInstance("Video cannot be played.");

  videoWidgetView = findViewById(R.id.video_view);
  videoWidgetView.setInfoButtonEnabled(false);
  videoWidgetView.setEventListener(new VrVideoEventListener() {
    @Override
    public void onLoadSuccess() {
      super.onLoadSuccess();
      progress.setVisibility(View.GONE);
    }

    @Override
    public void onLoadError(String errorMessage) {
      super.onLoadError(errorMessage);

      if (!tryDefaultFormat) {
        tryDefaultFormat = true;
        videoOptions.inputFormat = VrVideoView.Options.FORMAT_DEFAULT;
        startVideo();
      }
    }
  });

  uri = getIntent().getData();

  final String type = getMimeType(this, uri);

  videoOptions.inputFormat =
      "mp4".equals(type) ? VrVideoView.Options.FORMAT_DEFAULT : VrVideoView.Options.FORMAT_HLS;
  videoOptions.inputType = VrVideoView.Options.TYPE_MONO;
}