Question

我是Flutter的新手，尝试从api加载视频，但是视频播放器无法正常工作。我的_buildFilmsMainPages（）小部件中有PageView，每个页面都将从api获取自己的视频。

加载数据时出现错误：构建FutureBuilder>（脏，状态：_FutureBuilderState>＃033d3）时引发了以下NoSuchMethodError：方法'[]'在null上被调用。接收者：null 尝试致电：

加载后，此错误消失了。

当我点按播放（浮动操作按钮）时，我只能看到视频的第一帧，但声音正常。

当我点击停止按钮（浮动操作按钮）时，视频的第一帧消失了，但声音仍然有效。

  class HomePage extends StatefulWidget {
  HomePage({Key key, this.title}) : super(key: key);
 final String title;

 @override
 _ HomePageState createState() => _HomePageState();
}

 class _HomePageState extends State<HomePage> {

 VideoPlayerController _controller;
 Future<void> _initializeVideoPlayerFuture;
bool isVideo = false;
 int filmIndex = 0;

 @override
  void initState() {
  super.initState();
 }

  @override
  Widget build(BuildContext context) {
  return Scaffold (
   body: SingleChildScrollView(
      child: _buildFilmsMainPages(),
      )            
  );
}


   Widget _buildFilmsMainPages() =>
     FutureBuilder( 
        future:getMoviesListByDay(date))),
      builder: (BuildContext context, AsyncSnapshot snapshot) {

没有此代码，我会报错，但播放器无法正常工作无论如何都正确，并且在加载数据时出现错误

      _controller= VideoPlayerController.network
         (snapshot.data[filmIndex].media!=null? 
          snapshot.data[filmIndex].media.elementAt(1)
          :"https://flutter.github.io/assets-for-api- 
           docs/assets/videos/butterfly.mp4");
         _initializeVideoPlayerFuture =_controller.initialize();
         _controller.setLooping(true);



     if (snapshot.data != null) {
      return
       Column(
       children:<Widget> [
         SizedBox(
          height: 460.0,
           child: PageView.builder(
             pageSnapping: true,
             itemCount: snapshot.data.length,
             onPageChanged: (int index) {
             setState(() {
               filmIndex = index;

我想我应该在这里写这段代码

               _controller = VideoPlayerController.network
                (snapshot.data[filmIndex].media!=null? 
                snapshot.data[filmIndex].media.elementAt(1)
                   :"https://flutter.github.io/assets-for-api- 
                 docs/assets/videos/butterfly.mp4");
               _initializeVideoPlayerFuture = 
                    _controller.initialize();
               _controller.setLooping(true);




              });
             },
             itemBuilder: (context, index) {
                return Column(
                 children: <Widget>[
                    Container(margin: const 
                    EdgeInsets.symmetric(horizontal: 16.0),
                      child: ClipRRect(
                       borderRadius: BorderRadius.circular(8.0),
                       child: Container(
                        height: 250.0,
                        child: Stack(children: <Widget>[
                         Container(
                          child: GestureDetector(
                              child: isVideo ?
                              FutureBuilder(

                            future:_initializeVideoPlayerFuture,
                               builder: (context, snapshot) {
                                if (snapshot.connectionState ==
                                      ConnectionState.done) {
                                    return AspectRatio(
                                      aspectRatio: 16.0 / 12.0,
                                 child:VideoPlayer(_controller),
                                    );
                                  } else {
                                    return Center(
                                        child: 
                              CircularProgressIndicator());
                                  }
                                },
                              ) :
                              FadeInImage.assetNetwork(
                                placeholder: 
                           "assets/placeholder.jpg",
                                image:
                                snapshot.data[index].media!=null 
                  ? snapshot.data[index].media.elementAt(0): "",
                                fit: BoxFit.fill,

                      fadeInDuration:Duration(milliseconds: 50),
                              ),
                              onTap: () =>

                                        )
                                    ),
                                  )
                          )
                          ),
                            Row(children: <Widget>[
                              Container(
                       margin: const EdgeInsets.only(left: 16.0,
                                right: 16.0, top: 190.0),
                                  height: 40.0,
                                 width: 40.0,
                                  child: FittedBox(
                             child: FloatingActionButton(
                                 backgroundColor: Colors.white,
                                 foregroundColor: Colors.black,
                                     onPressed: () {
                                     setState(() {
                                      isVideo = !isVideo;
                                if (_controller.value.isPlaying) {
                                        _controller.pause();
                                      } else {
                                        _controller.play();
                                      }
                                     });
                                     },
                         child: Icon(_controller.value.isPlaying
                                ? Icons.pause : LineIcons.play,
                                    size: 30.0,)
                               ),
                             )

                   );

视频播放器抖动的问题

0 个答案: