我正在开发一个具有多个屏幕的应用程序。摄像头图像捕捉屏幕永远不会被主屏幕直接调用，而不是子屏幕。尽管当我将相机选择器代码放入主文件并执行时，它可以完美地作为一个单独的颤振项目工作。但是，当我通过使用有状态小部件类并通过 Navigator 推送调用它来执行相同操作时，它只是没有响应。相机开口部分。
调用相机屏幕的屏幕代码
import 'package:carryon/luggageupdatepage.dart';
import 'package:carryon/scannerscreen.dart';
import 'package:flutter/material.dart';
import 'allvalues.dart';
import 'login_screen.dart';
import 'welcome_screen.dart';
import 'auth.dart';
class DetailsPage extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Detailspage();
}
}
class Detailspage extends StatefulWidget {
@override
_DetailspageState createState() => _DetailspageState();
}
class _DetailspageState extends State<Detailspage>
with TickerProviderStateMixin{
final AuthServices _auth=AuthServices();
void _showDialog() {
// flutter defined function
showDialog(
context: context,
builder: (BuildContext context) {
// return object of type Dialog
return AlertDialog(
title: Text("Invalid PNR",
style: TextStyle(fontSize: 14),),
content: Text(
"Please neter a valid PNR number.",
style: TextStyle(fontSize: 12,),),
actions: <Widget>[
// usually buttons at the bottom of the dialog
new FlatButton(
child: new Text("Close"),
onPressed: () {
Navigator.of(context).pop();
},
),
],
);
},
);
}
AnimationController controller;
Animation<double> animation;
@override
initState() {
super.initState();
controller = AnimationController(
duration: const Duration(seconds: 3), vsync: this);
animation = CurvedAnimation(parent: controller, curve: Curves.easeIn);
controller.forward();
}
@override
Widget build(BuildContext context) {
return FadeTransition(
opacity: animation,
child: Scaffold(
resizeToAvoidBottomInset: false,
backgroundColor: Background_Color,
appBar: AppBar(
actions: <Widget>[
FlatButton.icon(onPressed: ()async{
await _auth.signOut();
Navigator.push(context,
MaterialPageRoute(
builder: (context)=>CarryOn()),);
},
icon: Icon(Icons.perm_identity), label: Text('Logout'))
],
title: Text(
'Flight CheckIn',
style: LoginScreenTextStyle.copyWith(fontSize: 20),
),
),
body: Column(
children: <Widget>[
SizedBox(height: 30,),
Container(
width: double.infinity,
color: Colors.green,
child: Text(
'Your Flight ${userdetails.FlightName} from ${userdetails.Departure_Destination} to ${userdetails.Arrival_Destination} on ${userdetails.Departure_Date} is on time. Kindly report one hour prior to boarding time.',
style: TextStyle(
fontSize: 15,
color: Colors.black,
),
),
),
SizedBox(height: 100,),
Row(
children: <Widget>[
SizedBox(width: 60,),
Image.asset('assets/images/flighticon.png',height: 100,width: 100,),
SizedBox(width:20),
Container(
height: 100,
child: Column(
children: <Widget>[
Container(
height: 20,
color: Colors.white,
child: Text(
'${userdetails.Departure_Destination}',
style: TextStyle(color: Colors.black),
),
),
SizedBox(height: 20,),
Container(
height: 20,
color: Background_Color,
child: Text(
'${userdetails.Departure_Time}hrs-${userdetails.Arrival_Time}hrs',
style: TextStyle(color: Colors.grey),
),
),
SizedBox(height: 20,),
Container(
height: 20,
color: Colors.white,
child: Text(
'${userdetails.Arrival_Destination}',
style: TextStyle(color: Colors.black),
),
),
],
),
),
],
),
SizedBox(height: 80,),
Container(
height: 50,width:250,
child: DecoratedBox(
decoration:ShapeDecoration(shape:roundedrectangle, color:Button_Color),
child: OutlineButton(
color:Button_Color,
borderSide: BorderSide(color:Colors.white,),
shape: roundedrectangle,
child: Center(child: Text('My Luggage Status')),
onPressed: ()
{
Navigator.push(context,
MaterialPageRoute(
builder: (context)=>LuggageUpdates()),);
},
),
),
),
SizedBox(height: 30,),
Container(
height: 50,width:250,
child: DecoratedBox(
decoration:ShapeDecoration(shape:roundedrectangle, color:Button_Color),
child: OutlineButton(
color:Button_Color,
borderSide: BorderSide(color:Colors.white,),
shape: roundedrectangle,
child: Center(child: Text('Repeat CheckIn')),
onPressed: ()
{
Navigator.push(context,
MaterialPageRoute(
builder: (context)=>MyApp()),);
},
),
),
),
],
),
),
);
}
}
我用来为相机屏幕执行的代码：
import 'package:flutter/material.dart';
import 'dart:io';
import 'package:image_picker/image_picker.dart';
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
File _image;
Future getImage(bool isCamera)
async{
File image;
if(isCamera)
{
image=await ImagePicker.pickImage(source: ImageSource.camera);
print('camera chale to sahi');
}
else
image=await ImagePicker.pickImage(source: ImageSource.gallery);
setState(() {
_image=image;
});
}
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: Text('Image Pick Demo',),
),
body: Column(
children: <Widget>[
IconButton(
icon: Icon(Icons.insert_drive_file),
onPressed:(){
getImage(false);
},
),
SizedBox(height: 10,),
IconButton(
icon: Icon(Icons.camera_alt),
onPressed: (){getImage(true);},
),
_image==null?Container():Image.file(_image,height: 300,width: 300,),
],
),
),
);
}
}
当直接由 main.dart 运行时，完全相同的代码可以工作，所以我在调用 camera_screen.dart 文件时犯了一些错误。