如何解决此问题 [错误：flutter/lib/ui/ui_dart_state.cc(199)] 未处理的异常：NoSuchMethodError：getter 'phone' 被调用为 null。
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【中文标题】如何解决此问题 [错误：flutter/lib/ui/ui_dart_state.cc(199)] 未处理的异常：NoSuchMethodError：getter \'phone\' 被调用为 null。错误？【英文标题】：How to fix this [ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: NoSuchMethodError: The getter 'phone' was called on null. error?如何解决此问题 [错误：flutter/lib/ui/ui_dart_state.cc(199)] 未处理的异常：NoSuchMethodError：getter 'phone' 被调用为 null。错误？ 【发布时间】：2021-09-24 13:00:55 【问题描述】：错误：
E/flutter (22800): [ERROR:flutter/lib/ui/ui_dart_state.cc(199)] 未处理的异常：NoSuchMethodError：getter 'phone' 被调用为 null。 E/颤振（22800）：接收器：空 E/flutter (22800)：尝试呼叫：电话 E/flutter (22800): #0 Object.noSuchMethod (dart:core-patch/object_patch.dart:54:5) E/flutter (22800): #1 _OtpscreenState.verifyPhone (package:userauth/Otpscreen.dart:172:35) E/flutter (22800): #2 _OtpscreenState.initState (package:userauth/Otpscreen.dart:209:5) E/flutter (22800): #3 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4711:57) E/flutter (22800): #4 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4548:5) E/flutter (22800): #5 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3611:14) E/flutter (22800): #6 Element.updateChild (package:flutter/src/widgets/framework.dart:3363:18) E/flutter (22800): #7 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6083:14) E/flutter (22800): #8 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3611:14) E/flutter (22800): #9 Element.updateChild (package:flutter/src/widgets/framework.dart:3363:18) E/flutter (22800): #10 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4599:16) E/flutter (22800): #11 Element.rebuild (package:flutter/src/widgets/framework.dart:4267:5) E/flutter (22800): #12 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4553:5) E/flutter (22800): #13 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4548:5) E/flutter (22800): #14 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3611:14) E/flutter (22800): #15 Element.updateChild (package:flutter/src/widgets/framework.dart:3363:18) E/flutter (22800): #16 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6083:14) E/flutter (22800): #17 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3611:14) E/flutter (22800): #18 Element.updateChild (package:flutter/src/widgets/framework.dart:3363:18) E/flutter (22800): #19 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6083:14) E/flutter (22800): #20 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3611:14) E/flutter (22800): #21 Element.updateChild (package:flutter/src/widgets/framework.dart:3363:18) E/flutter (22800): #22 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4599:16) E/flutter (22800): #23 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4746:11) E/flutter (22800): #24 Element.rebuild (package:flutter/src/widgets/framework.dart:4267:5) E/flutter (22800): #25 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4553:5) E/flutter (22800): #26 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4737:11) E/flutter (22800): #27 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4548:5) E/flutter (22800): #28 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3611:14) E/flutter (22800): #29 Element.updateChild (package:flutter/src/widgets/framework.dart:3363:18) E/flutter (22800): #30 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6083:14) E/flutter (22800): #31 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3611:14) E/flutter (22800): #32 Element.updateChild (package:flutter/src/widgets/framework.dart:3363:18) E/flutter (22800): #33 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6083:14) E/flutter (22800): #34 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3611:14) E/flutter (22800): #35 Element.updateChild (package:flutter/src/widgets/framework.dart:3363:18) E/flutter (22800): #36 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4599:16) E/flutter (22800): #37 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4746:11) E/flutter (22800): #38 Element.rebuild (package:flutter/src/widgets/framework.dart:4267:5) E/flutter (22800): #39 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4553:5) E/flutter (22800): #40 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4737:11) E/flutter (22800): #41 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4548:5) E/flutter (22800): #42 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3611:14) E/flutter (22800): #43 Element.updateChild (package:flutter/src/widgets/framework.dart:3363:18) E/flutter (22800): #44 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4599:16) E/flutter (22800): #45 Element.rebuild (package:flutter/src/widgets/framework
这是我的代码：
import 'package:flutter/material.dart';
import 'package:pinput/pin_put/pin_put.dart';
import 'package:pinput/pin_put/pin_put_state.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:userauth/Profilescreen.dart';
class Otpscreen extends StatefulWidget
String phone;
Otpscreen(this.phone);
@override
_OtpscreenState createState() => _OtpscreenState();
class _OtpscreenState extends State<Otpscreen>
final GlobalKey<ScaffoldState> _scaffoldkey = GlobalKey<ScaffoldState>();
late String otp;
late String _verificationCode;
final TextEditingController _pinPutController = TextEditingController();
final FocusNode _pinPutFocusNode = FocusNode();
final BoxDecoration pinPutDecoration = BoxDecoration(
color: Colors.blue,
borderRadius: BorderRadius.circular(10.0),
border: Border.all(
color: const Color.fromRGBO(126, 203, 224, 1),
),
);
@override
Widget build(BuildContext context)
return Scaffold(
body: SafeArea(
child: Column(
children: [
Expanded(
child: Padding(
padding: const EdgeInsets.only(top: 10, bottom: 10),
child: Column(
children: [
Padding(
padding: const EdgeInsets.only(right: 310),
child: RawMaterialButton(
onPressed: ()
Navigator.pop(context, "phone");
,
child: Icon(Icons.arrow_back),
),
),
SizedBox(height: 40),
Text(
"Verify Phone",
style: TextStyle(
fontWeight: FontWeight.bold,
fontSize: 20,
color: Colors.black),
),
SizedBox(height: 10),
Text(
"code is sent to $widget.phone",
style: TextStyle(
fontSize: 14,
fontWeight: FontWeight.w500,
color: Colors.grey),
),
Padding(
padding: const EdgeInsets.all(30.0),
child: PinPut(
fieldsCount: 6,
textStyle: const TextStyle(
fontSize: 25.0, color: Colors.white),
eachFieldWidth: 40.0,
eachFieldHeight: 55.0,
focusNode: _pinPutFocusNode,
controller: _pinPutController,
submittedFieldDecoration: pinPutDecoration,
selectedFieldDecoration: pinPutDecoration,
followingFieldDecoration: pinPutDecoration,
pinAnimationType: PinAnimationType.fade,
onSubmit: (pin) async
try
await FirebaseAuth.instance
.signInWithCredential(
PhoneAuthProvider.credential(
verificationId: _verificationCode,
smsCode: otp))
.then((value) async
if (value.user != null)
Navigator.pushAndRemoveUntil(
context,
MaterialPageRoute(
builder: (context) => Profilescreen()),
(route) => false);
);
catch (e)
FocusScope.of(context).unfocus();
_scaffoldkey.currentState!.showSnackBar(
SnackBar(content: Text("invalid OTP")));
,
),
),
SizedBox(
height: 20,
),
Center(
child: Padding(
padding: const EdgeInsets.only(
left: 20, right: 20, top: 0, bottom: 10),
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Center(
child: Text(
"Didn't receive an code?",
),
),
GestureDetector(
onTap: ()
Navigator.pushNamed(context, "phone");
,
child: Center(
child: Text(
"Request Again",
style: TextStyle(
color: Colors.black,
fontWeight: FontWeight.bold,
fontSize: 16,
),
),
),
),
],
),
),
),
SizedBox(height: 20),
RawMaterialButton(
onPressed: ()
Navigator.pushNamed(context, "profile");
,
fillColor: Colors.blue,
child: Padding(
padding: const EdgeInsets.fromLTRB(50, 15, 50, 15),
child: Text(
"VERIFY AND CONTINUE",
style: TextStyle(
fontSize: 16, fontWeight: FontWeight.bold),
),
),
),
],
),
),
),
],
),
),
);
verifyPhone() async
var widget;
await FirebaseAuth.instance.verifyPhoneNumber(
phoneNumber: "+91$widget.phone",
verificationCompleted: (PhoneAuthCredential credential) async
await FirebaseAuth.instance
.signInWithCredential(credential)
.then((value) async
if (value.user != null)
Navigator.pushAndRemoveUntil(
context,
MaterialPageRoute(builder: (context) => Profilescreen()),
(route) => false);
);
,
verificationFailed: (FirebaseAuthException e)
print(e.message);
,
codeSent: (String verificationID, int? resendToken)
setState(()
_verificationCode = verificationID;
);
,
codeAutoRetrievalTimeout: (String verificationID)
setState(()
var verificationCode = verificationID;
);
,
timeout: Duration(seconds: 60));
@override
void initState()
// TODO: implement initState
super.initState();
verifyPhone();
谢谢！
【问题讨论】：
您使用的是空安全吗？ 不，我没有升级我的版本。 【参考方案1】：在你的 verifyPhone() 函数中，你为什么要声明一个“widget”变量？？
尝试删除它
verifyPhone() async
var widget; <<--- remove this from your code
await FirebaseAuth.instance.verifyPhoneNumber(
phoneNumber: "+91$widget.phone",
verificationCompleted: (PhoneAuthCredential credential) async
await FirebaseAuth.instance
.signInWithCredential(credential)
.then((value) async
if (value.user != null)
Navigator.pushAndRemoveUntil(
context,
MaterialPageRoute(builder: (context) => Profilescreen()),
(route) => false);
);
,
verificationFailed: (FirebaseAuthException e)
print(e.message);
,
codeSent: (String verificationID, int? resendToken)
setState(()
_verificationCode = verificationID;
);
,
codeAutoRetrievalTimeout: (String verificationID)
setState(()
var verificationCode = verificationID;
);
,
timeout: Duration(seconds: 60));
【讨论】：
【参考方案2】：您正在尝试在此行中获取 widget.phone
var widget;
await FirebaseAuth.instance.verifyPhoneNumber(
phoneNumber: "+91$widget.phone", <-
但是，代码不是将 phone 作为参数传递给 Otpscreen，而是获取 phone 变量，在函数内部声明。由于变量为 null，因此返回 NoSuchMethodError。尝试删除var widget 声明。
【讨论】：
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