我需要pause当我移动到导航树上的另一个屏幕以节省电池和性能时相机。
我尝试过了dispose()
cameraController,但 flutter 从另一个屏幕返回时不会重新初始化状态(但这很明显)。
我使用相机的主要代码:
@override
void initState() {
super.initState();
availableCameras().then((cameras) {
setState(() {
_firstCamera = cameras.first;
_controller = CameraController(_firstCamera, ResolutionPreset.high);
_initializeControllerFuture = _controller.initialize();
});
});
}
@override
void dispose() {
_controller?.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return Scaffold(
key: _scaffoldKey,
body: Stack(
children: <Widget>[
FutureBuilder<void>(
future: _initializeControllerFuture,
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
return Stack(
alignment: FractionalOffset.center,
children: <Widget>[
new Positioned.fill(
child: _getCameraPreview(context),
),
...
],
);
} else {
return Center(child: CircularProgressIndicator());
}
},
),
Align(
alignment: Alignment.bottomCenter,
child: BottomAppBar(
color: Color.fromARGB(0, 0, 0, 0),
child: _getBottomAppBarRow(context),
),
),
],
),
);
}
_getCameraPreview(BuildContext context) {
final size = MediaQuery.of(context).size;
final deviceRatio = size.width / size.height;
return Transform.scale(
scale: _controller.value.aspectRatio / deviceRatio,
child: Center(
child: AspectRatio(
aspectRatio: _controller.value.aspectRatio,
child: CameraPreview(_controller),
),
),
);
}