处置VideoPlayerController后，在使用后退按钮时出现异常。
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());
}
},
),
));
}
但是当我按下后退按钮时，出现此错误:
Another exception was thrown: A VideoPlayerController was used after being disposed.
如何正确处置VideoPlayerController并加入后退按钮？
最佳答案
您可以在下面复制粘贴运行完整代码
并标记未标记的Navigator.push / Navigator.pushReplacement以检查效果
在您的情况下，您不需要处理controller，因为controller在此页面上是本地的，所以您只需执行_controller.pause()您使用Navigator.push转到下一页意味着您将从下一页开始pop如果您成功将dispose controller并将controller设置为null，则从下一页弹出时，您将收到错误消息，因为ojit_code将不再被调用，initState将不会再次被初始化
如果您使用controller，则会自动调用Navigator.pushReplacement，
您可以在演示代码中看到console show _controller.dispose。
工作演示
您可以从dispose页面上看到返回的视频，仍然可以播放
完整的代码
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: () {},
),
),
);
}
}
关于flutter - Flutter无法处置VideoPlayerController，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/59119668/