我将我的Flutter更新到了1.22.0版本，现在我的video_player给了我异常错误。在我更新Flutter之前它运行得很好。
这是我的错误信息：
E/flutter ( 8545): [ERROR:flutter/lib/ui/ui_dart_state.cc(177)] 未处理的异常: 'package:flutter/src/services/message_codec.dart': 断言失败，第111行第15个字符：'code != null'不为真。E/flutter ( 8545): #0_AssertionError._doThrowNew（dart:core-patch/errors_patch.dart:46:39） E/flutter ( 8545): #1 _AssertionError._throwNew（dart:core-patch/errors_patch.dart:36:5） E/flutter ( 8545): #2 new PlatformException（package:flutter/src/services/message_codec.dart:111:15）E/flutter ( 8545): #3 VideoPlayerApi.create（package:video_player_platform_interface/messages.dart:205:13） E/flutter ( 8545): #4 MethodChannelVideoPlayer.create（package:video_player_platform_interface/method_channel_video_player.dart:46:42）E/flutter ( 8545): #5 VideoPlayerController.initialize（package:video_player/video_player.dart:275:45） E/flutter ( 8545): #6 _ScreenBackgroundVideoState.initState（package:flow/widget/background/screen_background_video.dart:17:9）E/flutter ( 8545): #7 StatefulElement._firstBuild（package:flutter/src/widgets/framework.dart:4765:58） E/flutter ( 8545): #8 ComponentElement.mount（package:flutter/src/widgets/framework.dart:4601:5） E/flutter ( 8545): #9 Element.inflateWidget（package:flutter/src/widgets/framework.dart:3569:14）E/flutter ( 8545): #10 MultiChildRenderObjectElement.mount（package:flutter/src/widgets/framework.dart:6236:32） E/flutter ( 8545): #11 Element.inflateWidget（package:flutter/src/widgets/framework.dart:3569:14）E/flutter ( 8545): #12 Element.updateChild（package:flutter/src/widgets/framework.dart:3327:18） E/flutter ( 8545): #13 SingleChildRenderObjectElement.mount（package:flutter/src/widgets/framework.dart:6118:14）E/flutter ( 8545): #14 Element.inflateWidget（package:flutter/src/widgets/framework.dart:3569:14） E/flutter ( 8545): #15 Element.updateChild（package:flutter/src/widgets/framework.dart:3327:18）E/flutter ( 8545): #16 ComponentElement.performRebuild（package:flutter/src/widgets/framework.dart:4652:16） E/flutter ( 8545): #17 Element.rebuild（package:flutter/src/widgets/framework.dart:4343:5）E/flutter ( 8545): #18 ComponentElement._firstBuild（package:flutter/src/widgets/framework.dart:4606:5） E/flutter ( 8545): #19 ComponentElement.mount（package:flutter/src/widgets/framework.dart:4601:5）E/flutter ( 8545): #20 Element.inflateWidget（package:flutter/src/widgets/framework.dart:3569:14） E/flutter ( 8545): #21 Element.updateChild（package:flutter/src/widgets/framework.dart:3327:18）E/flutter ( 8545): #22 SingleChildRenderObjectElement.mount（package:flutter/src/widgets/framework.dart:6118:14） E/flutter ( 8545): #23 Element.inflateWidget（package:flutter/src/widgets/framework.dart:3569:14）E/flutter ( 8545): #24 Element.updateChild（package:flutter/src/widgets/framework.dart:3327:18） E/flutter ( 8545): #25 SingleChildRenderObjectElement.mount（package:flutter/src/widgets/framework.dart:6118:14）E/flutter ( 8545): #26 Element.inflateWidget（package:flutter/src/widgets/framework.dart:3569:14） E/flutter ( 8545): #27 Element.updateChild（package:flutter/src/widgets/framework.dart:3327:18）E/flutter ( 8545): #28 SingleChildRenderObjectElement.mount（package:flutter/src/widgets/framework.dart:6118:14） E/flutter ( 8545): #29 Element.inflateWidget（package:flutter/src/widgets/framework.dart:3569:14）E/flutter ( 8545): #30 Element.updateChild（package:flutter/src/widgets/framework.dart:3327:18） E/flutter ( 8545): #31 SingleChildRenderObjectElement.mount（package:flutter/src/widgets/framework.dart:6118:14）E/flutter ( 8545): #32 Element.inflateWidget（package:flutter/src/widgets/framework.dart:3569:14） E/flutter ( 8545): #33 Element.updateChild（package:flutter/src/widgets/framework.dart:3327:18）E/flutter ( 8545): #34 ComponentElement.performRebuild（package:flutter/src/widgets/framework.dart:4652:16） E/flutter ( 8545): #35 Element.rebuild（package:flutter/src/widgets这是我的代码：
import 'package:flutter/material.dart';
import 'package:video_player/video_player.dart';
class ScreenBackgroundVideo extends StatefulWidget {
@override
_ScreenBackgroundVideoState createState() => _ScreenBackgroundVideoState();
}
class _ScreenBackgroundVideoState extends State<ScreenBackgroundVideo> {
VideoPlayerController _controller;
@override
void initState() {
super.initState();
_controller = VideoPlayerController.asset('assets/vid/login.mp4')
// set background video using assets for login screen
..initialize().then((_) {
// Ensure the first frame is shown after the video is initialized, even before the play button has been pressed.
setState(() {});
}); // background video will play as soon as the splashscreen is closed
_controller.play();
_controller
.setLooping(true); // looping set to true for the background video
_controller.setVolume(0); // volume set to 0 for background video
}
@override
void dispose() {
super.dispose();
// TODO: implement dispose
_controller.dispose(); // Dispose the controller after play is done.
}
@override
Widget build(BuildContext context) {
return Container(
child: _controller.value.initialized
? AspectRatio(
aspectRatio: _controller.value.aspectRatio,
child: VideoPlayer(_controller),
)
: Container(),
);
}
}
需要帮助来解决这个问题。