颤振断言错误： 颤振："包：firebase_auth_platform_interface/src/method_channel/method_channel_user_credential.dar

Question

我正在使用Firebase，当我点击注册按钮时，不断收到这个烦人的消息：

颤动：'包：firebase_auth_platform_interface/src/method_channel/method_channel_user_credential.dart'：断言失败：第14行位置16：'数据！=null"：不为真。

代码运行良好。应用程序已成功构建并运行。当我输入手机、电子邮件和密码并点击注册按钮时，就会发生这种情况。我的代码是：

import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';
class Auth extends StatefulWidget {
@override
_AuthState createState() => _AuthState();
}
class _AuthState extends State<Auth> {
final _formKey = GlobalKey<FormState>();
final _password = TextEditingController(),
_email = TextEditingController(),
_phone = TextEditingController();
final _auth = FirebaseAuth.instance;
bool willLogin = true;
bool showPassword = false;
void _login() async {
_formKey.currentState.validate();
try {
final existingUser = await _auth.signInWithEmailAndPassword(
email: _email.text, password: _password.text);
if (existingUser != null) {
Navigator.pushNamed(context, '/home');
}
} catch (e) {
print(e);
}
}
void _signup() async {
_formKey.currentState.validate();
try {
final newUser = await _auth.createUserWithEmailAndPassword(
email: _email.text, password: _password.text);
if (newUser != null) {
Navigator.pushNamed(context, '/home');
}
} catch (e) {
print(e);
}
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Dog SOS"),
leading: Icon(Icons.pets),
),
body: Form(
key: _formKey,
child: ListView(
padding: const EdgeInsets.all(24),
children: [
const SizedBox(
height: 10,
),
Center(
child: CircleAvatar(
backgroundColor: Theme.of(context).primaryColor,
child: Icon(
Icons.shield,
color: Colors.white,
size: 50,
),
radius: 60,
),
),
const SizedBox(
height: 20,
),
if (!willLogin) ...[
TextFormField(
decoration: InputDecoration(
labelText: "Phone",
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(8),
),
),
keyboardType: TextInputType.phone,
textInputAction: TextInputAction.next,
controller: _phone,
validator: (value) =>
value.isEmpty ? "Please Enter Phone Number" : null,
),
const SizedBox(
height: 10,
),
],
TextFormField(
decoration: InputDecoration(
labelText: "Email",
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(8),
),
),
keyboardType: TextInputType.emailAddress,
textInputAction: TextInputAction.next,
controller: _email,
validator: (value) => value.isEmpty ? "Please Enter Email" : null,
),
const SizedBox(
height: 10,
),
TextFormField(
decoration: InputDecoration(
labelText: "Password",
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(8),
),
suffixIcon: IconButton(
icon: Icon(
showPassword
? Icons.visibility_off_outlined
: Icons.visibility_outlined,
),
onPressed: () {
setState(() {
showPassword = !showPassword;
});
},
),
),
obscureText: !showPassword,
textInputAction: TextInputAction.done,
controller: _password,
validator: (value) =>
value.isEmpty ? "Please Enter Password" : null,
),
const SizedBox(
height: 10,
),
RaisedButton(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(8),
),
child: Text(
willLogin ? "nLOGINn" : "nSIGN UPn",
style: Theme.of(context)
.textTheme
.button
.copyWith(color: Colors.white),
),
color: Theme.of(context).primaryColor,
onPressed: () {
if (_formKey.currentState.validate()) {
_formKey.currentState.save();
_login();
}
},
),
Row(
children: [
Text(willLogin
? "Don't have an account?"
: "Already have an account?"),
FlatButton(
child: Text(
willLogin ? "Create One." : "Login.",
style: Theme.of(context).textTheme.button.copyWith(
color: Theme.of(context).primaryColor,
),
),
onPressed: () {
setState(() {
willLogin = !willLogin;
if (_formKey.currentState.validate()) {
_formKey.currentState.save();
_signup();
}
});
},
),
],
),
],
),
),
);
}
}

Answer 1

问题在于：

onPressed: () {
setState(() {
willLogin = !willLogin;
if (_formKey.currentState.validate()) {
_formKey.currentState.save();
_signup();
}
});
},

单击此按钮时，您正在使用setState并将willLogin指定为false，因此它甚至没有调用_signup()，因为它正在立即调用build()方法。现在你有了willLogin = false，它在屏幕上显示了这个小部件：

child: Text(
willLogin ? "nLOGINn" : "nSIGN UPn",
style: Theme.of(context)
.textTheme
.button
.copyWith(color: Colors.white),
),
color: Theme.of(context).primaryColor,
onPressed: () {
if (_formKey.currentState.validate()) {
_formKey.currentState.save();
_login();
}
},
),

根据您的代码，如果willLogin为false，则显示Sign up文本并调用_login()方法。由于您正在调用_login()方法进行注册，因此会收到此错误，因为用户甚至没有在firebase身份验证中注册。

---

您需要做的是更改逻辑，要么删除setState，这样就会调用_signup()方法，要么保持原样，但将_login()更改为_signup()。

尝试以下操作：

child: Text(
willLogin ? "nLOGINn" : "nSIGN UPn",
style: Theme.of(context)
.textTheme
.button
.copyWith(color: Colors.white),
),
color: Theme.of(context).primaryColor,
onPressed: () {
if (_formKey.currentState.validate()) {
_formKey.currentState.save();
willLogin ? _login() : _signup();
}
},
),