调用时dispose， VideoPlayer
小部件仍在使用您的控制器。首先，您需要确保不再使用它（将controller的状态设置为null），然后再调用dispose。

我不确定您是如何通过Provider进行状态管理的，但我将举例说明如何使用常规State进行此操作。

  VideoPlayerController _controller;

  void _initController(String link) {
    _controller = VideoPlayerController.network(link)
      ..initialize().then((_) {
        setState(() {});
      });
  }

  Future<void> _onControllerChange(String link) async {
    if (_controller == null) {
      // If there was no controller, just create a new one
      _initController(link);
    } else {
      // If there was a controller, we need to dispose of the old one first
      final oldController = _controller;

      // Registering a callback for the end of next frame
      // to dispose of an old controller
      // (which won't be used anymore after calling setState)
      WidgetsBinding.instance.addPostFrameCallback((_) async {
        await oldController.dispose();

        // Initing new controller
        _initController(link);
      });

      // Making sure that controller is not used by setting it to null
      setState(() {
        _controller = null;
      });
    }
  }