我创建了一个主页,并且该用户可以登录该应用程序,在下一个屏幕中,用户可以看到他们的 Profiles 信息(仅限 Profiles 名称),并在其下面是signOut按钮 . 用户可以使用signOut按钮从应用程序中签名 . 但它不适合我 .
我想通过在details.dart中按signOut按钮从main.dart调用signOut方法(两个类都在不同的文件中)
但是,当我在详细信息中按signOut Button时,没有任何反应!
代码如下:
main.dart
import 'dart:async';
import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:google_sign_in/google_sign_in.dart';
import 'details.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
theme: new ThemeData(
primarySwatch: Colors.blue,
),
debugShowCheckedModeBanner: false,
home: new MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
@override
MyHomePageState createState() => MyHomePageState();
}
class MyHomePageState extends State<MyHomePage> {
final FirebaseAuth firebaseAuth = FirebaseAuth.instance;
final GoogleSignIn googleSignIn = GoogleSignIn();
static bool _LoginButton = true;
void signOut(){
googleSignIn.signOut();
setState((){
_LoginButton = true;
});
print(_LoginButton);
print("User Signed Out");
}
Future<FirebaseUser> _signIn() async{
if(_LoginButton==true){
setState((){
_LoginButton=false;
});
GoogleSignInAccount googleSignInAccount = await googleSignIn.signIn();
GoogleSignInAuthentication googleSignInAuthentication = await googleSignInAccount.authentication;
FirebaseUser firebaseUser = await firebaseAuth.signInWithGoogle(idToken: googleSignInAuthentication.idToken, accessToken: googleSignInAuthentication.accessToken);
print("Username is "+firebaseUser.displayName);
setState((){
_LoginButton = true;
});
Navigator.push(context, MaterialPageRoute(builder: (context) => details(firebaseUser.displayName,signOut)));
return firebaseUser;
}
}
bool _LoginButtonBool(){
return _LoginButton;
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text("Google auth with firebase"),),
body: Center(
child: _LoginButtonBool()?Container(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
MaterialButton(onPressed: _LoginButtonBool() ? () => _signIn().then((FirebaseUser firebaseuser ) =>print(firebaseuser)).catchError((e) => print(e)): null,
child: Text("Login"),color: Colors.orange,),
],
),
):CircularProgressIndicator(backgroundColor: Colors.greenAccent.withOpacity(0.01),),
),
);
}
}
details.dart
import 'package:flutter/material.dart';
import 'package:flutter_auth/main.dart';
class details extends StatelessWidget {
String name;
final Function callback;
details(this.name,this.callback);
@override
Widget build(BuildContext context) {
return Scaffold(
body:Center(child: Column(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
Text(name),
MaterialButton(onPressed: () => callback,
child: Text("Log out"),color: Colors.orange),
],
),),
);
}
}
2 回答
在DetailsPage中导入HomePage类并从中创建一个新实例,然后调用所需的方法(如果它是公共方法) .
您必须小心您要执行的操作,因为您可能正在访问未安装的页面/窗口小部件 . 想象一下,你做了一个
pushReplacement(new MaterialPageroute(...))
. 树中不再提供上一页,因此您无法访问它或其任何方法 .除非您的树中有明确的父子关系,否则您应该将逻辑抽象为外部或业务逻辑类 . 因此,您确定要调用类的活动实例 .
下面是一个使用Business对象传递的示例 . 如果你使用其他模式,如BLOC,ScopedModel,Streams等,会更好 . 但为了简单起见,我认为这应该足够了 .
如果您仍想调用另一个页面中的某个函数,并且您确定该页面已挂载(您已经完成了
push
而不是pushReplacement
),则可以执行以下操作 . (小心轻放)