Question

我正在尝试获取编写在我的 Youtube_player_flutter 文件中的 VideoCard.dart 包的 YouTube 视频链接。现在我将视频的链接作为参数传递给我创建的构造函数，但我得到了 The instance member 'widget' can't be accessed in an initializer.

我认为问题在于使用无状态小部件，但即使将其更改为有状态，问题仍然存在。

class _VideoCardState extends State<VideoCard> {
  // static String videoID = 'PQSagzssvUQ';
  String videoId = widget.url;
  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    videoId = widget.url;
  }

  YoutubePlayerController _controller = YoutubePlayerController(
    initialVideoId: videoId,
    flags: YoutubePlayerFlags(
      autoPlay: true,
      mute: false,
    ),
  );
  @override
  Widget build(BuildContext context) {
    return Container(
      height: 200,
      child: Container(
        decoration: BoxDecoration(
          color: Color(0xffff8f8f8),
          borderRadius: BorderRadius.circular(15),
        ),
        child: YoutubePlayer(
          controller: _controller,
          liveUIColor: Colors.amber,
          showVideoProgressIndicator: true,
        ),
      ),
    );
  }
}

更新 1：

class _VideoCardState extends State<VideoCard> {
  String get videoId => widget.url;

  // videoId = YoutubePlayer.convertUrlToId(
  //         "https://www.youtube.com/watch?v=S9bCLPwzSC0")
  //     .toString();
  @override
  void initState() {
    super.initState();
    // print(widget.url);
    videoId = widget.url;
  }

  YoutubePlayerController _controller = YoutubePlayerController(
    initialVideoId: videoId, ------------------------> The instance member 'videoId' can't be accessed in an initializer.
    flags: YoutubePlayerFlags(
      autoPlay: true,
      mute: false,
    ),
  );
  @override
  Widget build(BuildContext context) {
    return Container(
      height: 200,
      child: Container(
        decoration: BoxDecoration(
          color: Color(0xffff8f8f8),
          borderRadius: BorderRadius.circular(15),
        ),
        child: YoutubePlayer(
          controller: _controller,
          liveUIColor: Colors.amber,
          showVideoProgressIndicator: true,
        ),
      ),
    );
  }
}

Answer 1

您可以尝试使用 getter，类似于以下代码：

class _VideoCardState extends State<VideoCard> {
  String get videoId => widget.url;

  YoutubePlayerController get _controller => YoutubePlayerController(
    initialVideoId: videoId,
    flags: YoutubePlayerFlags(
      autoPlay: true,
      mute: false,
    ),
  );

  ...

}

Answer 2

这对我有用：

class _VideoCardState extends State<VideoCard> {
  late String videoId;
  late YoutubePlayerController _controller;

  @override
  void initState() {
    super.initState();
    videoId = YoutubePlayer.convertUrlToId(widget.url).toString();

    _controller = YoutubePlayerController(
      initialVideoId: videoId,
      flags: YoutubePlayerFlags(
        autoPlay: false,
        mute: false,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      height: 200,
      child: Container(
        decoration: BoxDecoration(
          color: Color(0xffff8f8f8),
          borderRadius: BorderRadius.circular(15),
        ),
        child: YoutubePlayer(
          controller: _controller,
          liveUIColor: Colors.amber,
          showVideoProgressIndicator: true,
        ),
      ),
    );
  }
}

颤振：“无法在初始化程序中访问实例成员 'widget'。”

2 个答案: