firebase - 如何在等待来自 Firebase 的身份验证时显示圆形进度指示器
问题描述
我有一个通过 Firebase 身份验证的登录页面，我想在仍在进行身份验证的同时显示一个圆形进度指示器。我在登录按钮的 catch 块中插入了 if 语句，用于处理登录过程中可能出现的错误
如果firebase服务器没有引发错误，我想显示圆形指示器我是编码新手，请帮助我。
下面是登录页面的代码
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';
import 'package:fluttertoast/fluttertoast.dart';
import 'package:user_details/fromJP/Scan_QR.dart';
import 'package:user_details/fromJP/load_widget.dart';
import 'Register.dart';
class Login extends StatefulWidget {
@override
_LoginState createState() => _LoginState();
}
class _LoginState extends State<Login> {
final formKey = GlobalKey<FormState>();
bool loading = false;
TextEditingController _emailController = TextEditingController();
TextEditingController _passwordController = TextEditingController();
String errorMessage;
@override
Widget build(BuildContext context) {
final GlobalKey<ScaffoldState> _scafoldKey = GlobalKey<ScaffoldState>();
return loading
? Loading()
: Scaffold(
key: _scafoldKey,
appBar: AppBar(
title: Text("Jinjer Pay"),
),
body: Container(
alignment: Alignment.center,
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("lib/bg.jpg"), fit: BoxFit.cover)),
child: Form(
key: formKey,
child: SingleChildScrollView(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Container(
margin: EdgeInsets.fromLTRB(15, 0, 15, 0),
padding: EdgeInsets.all(35),
decoration: BoxDecoration(
shape: BoxShape.rectangle,
color: Colors.white,
borderRadius:
BorderRadius.all(Radius.circular(20))),
child: Column(
children: <Widget>[
SizedBox(
height: 20,
),
TextFormField(
decoration:
new InputDecoration(hintText: "Email"),
keyboardType: TextInputType.emailAddress,
controller: _emailController,
),
SizedBox(
height: 20,
),
TextFormField(
decoration:
new InputDecoration(hintText: "Password"),
obscureText: true,
enableSuggestions: false,
controller: _passwordController,
),
SizedBox(
height: 20,
),
RaisedButton(
child: Text(
"Log In",
style: TextStyle(fontSize: 19),
),
color: Colors.amberAccent,
elevation: 10,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(15)),
onPressed: () async {
if (formKey.currentState.validate()) {
setState(() => loading = true);
try {
UserCredential res;
String userID;
res = (await FirebaseAuth.instance
.signInWithEmailAndPassword(
email: _emailController.text,
password:
_passwordController.text));
userID = res.user.uid;
if (res == null) {
setState(() {
loading = false;
});
}
if (res != null) {
Navigator.pop(context);
Navigator.of(context).push(
MaterialPageRoute(
builder: (context) => Scan_QR()),
);
}
} catch (e) {
if (e.code == "unknown") {
Fluttertoast.showToast(
msg:
"Email/Password Field cannot be Empty",
toastLength: Toast.LENGTH_SHORT,
gravity: ToastGravity.CENTER,
timeInSecForIosWeb: 1,
backgroundColor: Colors.redAccent,
textColor: Colors.white,
fontSize: 16.0);
}
if (e.code == "wrong-password") {
Fluttertoast.showToast(
msg: "Your password is incorrect",
toastLength: Toast.LENGTH_SHORT,
gravity: ToastGravity.CENTER,
timeInSecForIosWeb: 1,
backgroundColor: Colors.redAccent,
textColor: Colors.white,
fontSize: 16.0);
}
if (e.code == "invalid-email") {
Fluttertoast.showToast(
msg:
"Email/Password Field cannot be Empty",
toastLength: Toast.LENGTH_SHORT,
gravity: ToastGravity.CENTER,
timeInSecForIosWeb: 1,
backgroundColor: Colors.redAccent,
textColor: Colors.white,
fontSize: 16.0);
}
if (e.code == "user-not-found") {
Fluttertoast.showToast(
msg:
"No User found with this email",
toastLength: Toast.LENGTH_SHORT,
gravity: ToastGravity.CENTER,
timeInSecForIosWeb: 1,
backgroundColor: Colors.redAccent,
textColor: Colors.white,
fontSize: 16.0);
}
if (e.code == "user-disabled") {
Fluttertoast.showToast(
msg:
"user with this email has been disabled",
toastLength: Toast.LENGTH_SHORT,
gravity: ToastGravity.CENTER,
timeInSecForIosWeb: 1,
backgroundColor: Colors.redAccent,
textColor: Colors.white,
fontSize: 16.0);
}
if (e.code == "too-many-requests") {
Fluttertoast.showToast(
msg:
"Too many requests, try again later",
toastLength: Toast.LENGTH_SHORT,
gravity: ToastGravity.CENTER,
timeInSecForIosWeb: 1,
backgroundColor: Colors.redAccent,
textColor: Colors.white,
fontSize: 16.0);
}
print(e);
//_emailController.text = "";
_passwordController.text = "";
}
}
},
),
SizedBox(
height: 20,
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
"Not Registered? ",
style: TextStyle(fontSize: 19),
),
SizedBox(width: 5),
InkWell(
onTap: () {
Navigator.of(context).push(
MaterialPageRoute(
builder: (context) => Register()),
);
},
child: Text(
"Register",
style: TextStyle(
color: Colors.blue, fontSize: 19),
),
),
SizedBox(
height: 20,
),
],
),
],
))
],
),
),
),
),
);
}
}
解决方案
您可以showDialog使用Center(child:CircularProgressIndicator())intry块，Navigator.pop(context);当您成功或抛出错误时