Flutter 颤振无法处理VideoPlayerController

在处理VideoPlayerController后，使用“后退”按钮时引发异常

我的VideoPlayer和VideoPlayerController设置如下：

 String url;
 var plan;
_VideoPlayerScreenState(this.url,{this.plan});

 Future<Null> OnWillPop(){

_controller.dispose();

if(plan!=null)
Navigator.push(context, MaterialPageRoute(builder: (context)=>
ListSession(plan :plan)));
else
  Navigator.push(context, MaterialPageRoute(builder: (context)=>
ListMoves()));

}
VideoPlayerController _controller;
Future<void> _initializeVideoPlayerFuture;

@override
void initState() {
 _controller = VideoPlayerController.network(
  url,
 );

// Initialize the controller and store the Future for later use.
_initializeVideoPlayerFuture = _controller.initialize();

// Use the controller to loop the video.
_controller.setLooping(true);
_controller.play();
super.initState();
}

@override
void dispose() {
 print("+++++++++++++++++++++++++++++++++++++++++++");
_controller.dispose();
 super.dispose();
}

 @override
 Widget build(BuildContext context) {
 return WillPopScope(onWillPop: OnWillPop,child:Scaffold(

   // Use a FutureBuilder to display a loading spinner while waiting for the
   // VideoPlayerController to finish initializing.
   body: FutureBuilder(
    future: _initializeVideoPlayerFuture,
    builder: (context, snapshot) {
      if (snapshot.connectionState == ConnectionState.done) {
        // If the VideoPlayerController has finished initialization, use
        // the data it provides to limit the aspect ratio of the video.
        return Center(
          child: AspectRatio(
            aspectRatio: _controller.value.aspectRatio,
            // Use the VideoPlayer widget to display the video.
            child: VideoPlayer(_controller),
          ),
        );
      } else {
        // If the VideoPlayerController is still initializing, show a
        // loading spinner.
        return Center(child: CircularProgressIndicator());
      }
    },
  ),
 ));
}

---

如何正确处置我的VideoPlayerController并合并后退按钮？

您可以复制下面的粘贴运行完整代码
并标记取消标记

Navigator.push

/

Navigator.pushReplacement

以检查效果
在您的情况下，您不需要处理

控制器

，因为

控制器

是此页面的本地部分，您只需执行

\u controller.pause（）

您可以使用

Navigator。按

转到下一页意味着您将从下一页

弹出

。
如果您

dispose controller

并成功地将

controller

设置为

null

，当从下一页弹出时，您将得到一个错误，因为

initState

不会再次调用，

controller

不会再次初始化

如果使用

Navigator.pushReplacement

，将自动调用

dispose

，
您可以在演示代码中看到console show _controller.dispose

工作演示
从

ListMove

页面返回时，您可以看到视频仍然可以播放

完整代码

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:video_player/video_player.dart';

void main() => runApp(VideoPlayerApp());

class VideoPlayerApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Video Player Demo',
      home: VideoPlayerScreen(),
    );
  }
}

class VideoPlayerScreen extends StatefulWidget {
  VideoPlayerScreen({Key key}) : super(key: key);

  @override
  _VideoPlayerScreenState createState() => _VideoPlayerScreenState();
}

class _VideoPlayerScreenState extends State<VideoPlayerScreen> {
  VideoPlayerController _controller;
  VideoPlayerController _oldController;
  Future<void> _initializeVideoPlayerFuture;

  @override
  void initState() {
    print("initState");
    // Create and store the VideoPlayerController. The VideoPlayerController
    // offers several different constructors to play videos from assets, files,
    // or the internet.
    _controller = VideoPlayerController.network(
      'https://flutter.github.io/assets-for-api-docs/assets/videos/butterfly.mp4',
    );

    // Initialize the controller and store the Future for later use.
    _initializeVideoPlayerFuture = _controller.initialize();

    // Use the controller to loop the video.
    _controller.setLooping(true);

    super.initState();
  }

  @override
  void dispose() {
    print("_controller.dispose");
    // Ensure disposing of the VideoPlayerController to free up resources.
    //_initializeVideoPlayerFuture = null;
    _controller.dispose();

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () async {
        await _controller.pause();
        Navigator.push(
            context, MaterialPageRoute(builder: (context) => ListMoves()));

        /*Navigator.pushReplacement(
            context, MaterialPageRoute(builder: (context) => ListMoves()));*/
      },
      child: Scaffold(
        appBar: AppBar(
          title: Text('Butterfly Video'),
        ),
        // Use a FutureBuilder to display a loading spinner while waiting for the
        // VideoPlayerController to finish initializing.
        body: FutureBuilder(
          future: _initializeVideoPlayerFuture,
          builder: (context, snapshot) {
            if (snapshot.connectionState == ConnectionState.done) {
              // If the VideoPlayerController has finished initialization, use
              // the data it provides to limit the aspect ratio of the video.
              return AspectRatio(
                aspectRatio: _controller.value.aspectRatio,
                // Use the VideoPlayer widget to display the video.
                child: VideoPlayer(_controller),
              );
            } else {
              // If the VideoPlayerController is still initializing, show a
              // loading spinner.
              return Center(child: CircularProgressIndicator());
            }
          },
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () {
            // Wrap the play or pause in a call to `setState`. This ensures the
            // correct icon is shown.
            setState(() {
              // If the video is playing, pause it.
              if (_controller.value.isPlaying) {
                _controller.pause();
              } else {
                // If the video is paused, play it.
                _controller.play();
              }
            });
          },
          // Display the correct icon depending on the state of the player.
          child: Icon(
            _controller.value.isPlaying ? Icons.pause : Icons.play_arrow,
          ),
        ), // This trailing comma makes auto-formatting nicer for build methods.
      ),
    );
  }
}

class ListMoves extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('List Movies'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('Launch screen'),
          onPressed: () {},
        ),
      ),
    );
  }
}

导入'dart:async'；
进口“包装：颤振/材料.省道”；
导入“package:video_player/video_player.dart”；
void main（）=>runApp（VideoPlayerApp（））；
类VideoPlayerApp扩展了无状态小部件{
@凌驾
小部件构建（构建上下文）{
返回材料PP(
标题：“视频播放器演示”，
主页：视频播放器屏幕（），
);
}
}
类VideoPlayerScreen扩展StatefulWidget{
视频播放器屏幕（{Key}）：超级（Key:Key）；
@凌驾
_VideoPlayerScreenState createState（）=>\u VideoPlayerScreenState（）；
}
类\u VideoPlayerScreenState扩展状态{
视频播放控制器\u控制器；
视频播放控制器（旧控制器）；
未来(Future)初始设定未来玩家;；
@凌驾
void initState（）{
打印（“初始状态”）；
//创建并存储VideoPlayerController。VideoPlayerController
//提供多个不同的构造函数来播放来自资产、文件、，
//或者互联网。
_控制器=VideoPlayerController.network(
'https://flutter.github.io/assets-for-api-docs/assets/videos/butterfly.mp4',
);
//初始化控制器并存储将来使用的数据。
_initializeVideoPlayerFuture=_controller.initialize（）；
//使用控制器循环播放视频。
_控制器。设置循环（真）；
super.initState（）；
}
@凌驾
无效处置（）{
打印（“_controller.dispose”）；
//确保处置VideoPlayerController以释放资源。
//_initializeVideoPlayerFuture=null；
_controller.dispose（）；
super.dispose（）；
}
@凌驾
小部件构建（构建上下文）{
返回式示波器(
onWillPop:（）异步{
等待控制器暂停（）；
导航器。推(
context，MaterialPageRoute（builder:（context）=>ListMoves（））；
/*导航器。更换(
context，MaterialPageRoute（builder:（context）=>ListMoves（））*/
},
孩子：脚手架(
appBar:appBar(
标题：文本（“蝴蝶视频”），
),
//使用FutureBuilder在等待加载时显示加载微调器
//VideoPlayerController完成初始化。
正文：未来建设者(
未来：_initializevideoplayer未来，
生成器：（上下文，快照）{
if（snapshot.connectionState==connectionState.done）{
//如果VideoPlayerController已完成初始化，请使用
//它提供的数据用于限制视频的纵横比。
返回AspectRatio(
aspectRatio:_controller.value.aspectRatio，
//使用VideoPlayer小部件显示视频。
子项：视频播放器（_控制器），
);
}否则{
//如果VideoPlayerController仍在初始化，则显示
//加载旋转器。
返回中心（子项：CircularProgressIndicator（））；
}
},
),
浮动操作按钮：浮动操作按钮(
已按下：（）{
//在调用“setState”时结束播放或暂停。这样可以确保
//显示正确的图标。
设置状态（）{
//如果正在播放视频，请将其暂停。
if（_controller.value.isPlaying）{
_controller.pause（）；
}否则{
//如果视频暂停，请播放它。
_controller.play（）；
}
});
},
//根据播放机的状态显示正确的图标。
子：图标(
_controller.value.isplay？图标。暂停：图标。播放箭头，
),
)，//此尾随逗号使生成方法的自动格式设置更方便。
),
);
}
}
类ListMoves扩展了无状态小部件{
@凌驾
小部件构建（构建上下文）{
返回脚手架(
appBar:appBar(
标题：文本（“电影列表”），
),
正文：中(
孩子：升起按钮(
子项：文本（“启动屏幕”），
按下：（）{}，
),
),
);
}
}

请看一下我的答案

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:video_player/video_player.dart';

void main() => runApp(VideoPlayerApp());

class VideoPlayerApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Video Player Demo',
      home: VideoPlayerScreen(),
    );
  }
}

class VideoPlayerScreen extends StatefulWidget {
  VideoPlayerScreen({Key key}) : super(key: key);

  @override
  _VideoPlayerScreenState createState() => _VideoPlayerScreenState();
}

class _VideoPlayerScreenState extends State<VideoPlayerScreen> {
  VideoPlayerController _controller;
  VideoPlayerController _oldController;
  Future<void> _initializeVideoPlayerFuture;

  @override
  void initState() {
    print("initState");
    // Create and store the VideoPlayerController. The VideoPlayerController
    // offers several different constructors to play videos from assets, files,
    // or the internet.
    _controller = VideoPlayerController.network(
      'https://flutter.github.io/assets-for-api-docs/assets/videos/butterfly.mp4',
    );

    // Initialize the controller and store the Future for later use.
    _initializeVideoPlayerFuture = _controller.initialize();

    // Use the controller to loop the video.
    _controller.setLooping(true);

    super.initState();
  }

  @override
  void dispose() {
    print("_controller.dispose");
    // Ensure disposing of the VideoPlayerController to free up resources.
    //_initializeVideoPlayerFuture = null;
    _controller.dispose();

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () async {
        await _controller.pause();
        Navigator.push(
            context, MaterialPageRoute(builder: (context) => ListMoves()));

        /*Navigator.pushReplacement(
            context, MaterialPageRoute(builder: (context) => ListMoves()));*/
      },
      child: Scaffold(
        appBar: AppBar(
          title: Text('Butterfly Video'),
        ),
        // Use a FutureBuilder to display a loading spinner while waiting for the
        // VideoPlayerController to finish initializing.
        body: FutureBuilder(
          future: _initializeVideoPlayerFuture,
          builder: (context, snapshot) {
            if (snapshot.connectionState == ConnectionState.done) {
              // If the VideoPlayerController has finished initialization, use
              // the data it provides to limit the aspect ratio of the video.
              return AspectRatio(
                aspectRatio: _controller.value.aspectRatio,
                // Use the VideoPlayer widget to display the video.
                child: VideoPlayer(_controller),
              );
            } else {
              // If the VideoPlayerController is still initializing, show a
              // loading spinner.
              return Center(child: CircularProgressIndicator());
            }
          },
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () {
            // Wrap the play or pause in a call to `setState`. This ensures the
            // correct icon is shown.
            setState(() {
              // If the video is playing, pause it.
              if (_controller.value.isPlaying) {
                _controller.pause();
              } else {
                // If the video is paused, play it.
                _controller.play();
              }
            });
          },
          // Display the correct icon depending on the state of the player.
          child: Icon(
            _controller.value.isPlaying ? Icons.pause : Icons.play_arrow,
          ),
        ), // This trailing comma makes auto-formatting nicer for build methods.
      ),
    );
  }
}

class ListMoves extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('List Movies'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('Launch screen'),
          onPressed: () {},
        ),
      ),
    );
  }
}