具有类似_cameraOn = true的变量。如果为true，则显示CameraPreview，否则为false。导航到另一个屏幕时，将其设置为false
您可以在单独的小部件中拥有与相机相关的功能。因此，每次显示时都会对其进行初始化，而在不显示时将对其进行处理。
一个简单的工作示例
import 'dart:async';import 'package:flutter/material.dart';import 'package:camera/camera.dart';List<CameraDescription> cameras;Future<void> main() async { cameras = await availableCameras(); runApp(MaterialApp( home: CameraApp(), ));}class CameraApp extends StatefulWidget { @override _CameraAppState createState() => _CameraAppState();}class _CameraAppState extends State<CameraApp> { bool _cameraOn = true; @override Widget build(BuildContext context) { return Scaffold( body: Column( children: <Widget>[ Expanded( child: _cameraOn ? Camera() : Container(), ), FlatButton( onPressed: () { setState(() { _cameraOn = false; }); Navigator.push( context, MaterialPageRoute(builder: (BuildContext context) => Post())).then((res) { setState(() { _cameraOn = true; }); }).catchError((err) { print(err); }); }, child: Text("NEXT PAGE"), ), ], ), ); }}class Camera extends StatefulWidget { @override _CameraState createState() => _CameraState();}class _CameraState extends State<Camera> { CameraController controller; @override void initState() { super.initState(); controller = CameraController(cameras[0], ResolutionPreset.medium); controller.initialize().then((_) { if (!mounted) { return; } setState(() {}); }); } @override Widget build(BuildContext context) { if (!controller.value.isInitialized) { return Container(); } return AspectRatio( aspectRatio: controller.value.aspectRatio, child: CameraPreview(controller), ); } @override void dispose() { controller?.dispose(); super.dispose(); }}class Post extends StatelessWidget { @override Widget build(BuildContext context) { return Scaffold( body: Text("Post"), ); }}
