我正在播放视频并没有问题但是当导航到另一个页面时,控制台说这个 .
我尝试了我提出的所有内容,如检查 mounted
但没有一个有效 .
我错过了什么?有谁知道如何解决?
flutter:在调度VideoPlayerController的通知时抛出以下断言:在构建期间调用flutter:setState()或markNeedsBuild() . flutter:这个VideoProgressIndicator小部件不能被标记为需要构建,因为框架是颤动的:已经在构建小部件的过程中 . 可以将窗口小部件标记为需要在flutter:build阶段中构建,只有当其中一个祖先正在构建时才构建 . 这个例外是允许的,因为flutter:框架在子节点之前构建父窗口小部件,这意味着一个脏的后代总是会颤动:构建 . 否则,在此构建阶段,框架可能不会访问此窗口小部件 . flutter:调用setState()或markNeedsBuild()的小部件是:flutter:VideoProgressIndicator(state:_VideoProgressIndicatorState#09ac7)
Code:
class _VideoScreenState extends State<VideoScreen> {
VideoPlayerController _controller;
FadeAnimation imageFadeAnim =
new FadeAnimation(child: const Icon(Icons.play_arrow, size: 100.0));
VoidCallback listener;
bool _isPlaying = false;
List<String> videos = [
'http://www.sample-videos.com/video/mp4/720/big_buck_bunny_720p_20mb.mp4',
];
_VideoScreenState() {
listener = () {
if (mounted) setState(() {});
};
}
Future _videoOnTap() async {
if (!_controller.value.initialized) {
return;
}
if (_controller.value.isPlaying) {
imageFadeAnim = new FadeAnimation(
child: Icon(Icons.pause,
color: Colors.white.withOpacity(0.3), size: 75.0));
await _controller.pause();
} else {
imageFadeAnim = new FadeAnimation(
child: Icon(Icons.play_arrow,
color: Colors.white.withOpacity(0.3), size: 75.0));
await _controller.play();
}
}
Future _startVideoPlayer(int index) async {
if (_controller != null) {
await _controller.dispose();
}
_controller = VideoPlayerController.network(videos[index])
..addListener(() {
final bool isPlaying = _controller.value.isPlaying;
if (isPlaying != _isPlaying) {
if (mounted)
setState(() {
_isPlaying = isPlaying;
});
}
})
..initialize().then((_) async {
await _controller.play();
if (mounted) setState(() {});
});
}
@override
void initState() {
SystemChrome.setEnabledSystemUIOverlays([]);
_startVideoPlayer(0);
super.initState();
}
@override
void deactivate() {
_controller?.setVolume(0.0);
_controller?.removeListener(listener);
super.deactivate();
}
@override
void dispose() {
_controller?.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
final List<Widget> children = <Widget>[
new GestureDetector(
child: new Center(
child: _controller.value.initialized
? new AspectRatio(
aspectRatio: _controller.value.aspectRatio,
child: new VideoPlayer(_controller))
: new Container(),
),
onTap: _videoOnTap,
),
new Align(
alignment: Alignment.topCenter,
child: new VideoProgressIndicator(
_controller,
allowScrubbing: false,
colors: VideoProgressColors(
backgroundColor: Colors.black.withOpacity(0.5),
playedColor: Colors.white),
),
),
new Center(child: imageFadeAnim),
];
return new Scaffold(
backgroundColor: Colors.black,
body: new SafeArea(
top: true,
left: false,
right: false,
bottom: false,
child: new Stack(
fit: StackFit.passthrough,
children: children,
),
),
);
}
}
class FadeAnimation extends StatefulWidget {
final Widget child;
final Duration duration;
FadeAnimation({this.child, this.duration: const Duration(milliseconds: 300)});
@override
_FadeAnimationState createState() => new _FadeAnimationState();
}
class _FadeAnimationState extends State<FadeAnimation>
with SingleTickerProviderStateMixin {
AnimationController animationController;
@override
void initState() {
super.initState();
animationController =
new AnimationController(duration: widget.duration, vsync: this);
animationController.addListener(() {
if (mounted) {
setState(() {});
}
});
animationController.forward(from: 0.0);
}
@override
void deactivate() {
animationController.stop();
super.deactivate();
}
@override
void didUpdateWidget(FadeAnimation oldWidget) {
super.didUpdateWidget(oldWidget);
if (oldWidget.child != widget.child) {
animationController.forward(from: 0.0);
}
}
@override
void dispose() {
animationController.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return animationController.isAnimating
? new Container(
width: 75.0,
height: 75.0,
decoration: new BoxDecoration(
color: Colors.black.withOpacity(0.01),
shape: BoxShape.circle,
),
child: widget.child,
)
: new Container();
}
}