Flutter：当我在我的应用程序中使用 try 和 catch 方法时，dart 没有捕获错误

Question

我目前正在重设密码页面。我正在使用 firebase auth，我正在尝试使用“try catch”来捕获错误。当我以错误的格式输入电子邮件或将其留空时，我想显示一些警告对话框。但是，当我写错电子邮件或将其留空时，我的应用程序崩溃并给出此错误消息：

发生异常。 PlatformException（PlatformException（无效电子邮件，电子邮件地址格式错误。，{code：无效电子邮件，消息：电子邮件地址格式错误。，nativeErrorMessage：电子邮件地址格式错误。，nativeErrorCode：17008，additionalData：{ }}，空））

完整代码：

 // ignore_for_file: use_build_context_synchronously
    import 'dart:io';
    import 'package:firebase_auth/firebase_auth.dart';
    import 'package:flutter/cupertino.dart';
    import 'package:flutter/material.dart';
    import 'package:petinonedemo/main.dart';
    
    class ForgotPasswordPage extends StatefulWidget {
      const ForgotPasswordPage({super.key});
    
      @override
      State<ForgotPasswordPage> createState() => _ForgotPasswordPageState();
    }

class _ForgotPasswordPageState extends State<ForgotPasswordPage> {
  final TextEditingController _emailController = TextEditingController();
  final TextEditingController _phoneNumberController = TextEditingController();

  @override
  void dispose() {
    _emailController.dispose();
    _phoneNumberController.dispose();
    super.dispose();
  }

  void _showIOSAlert(BuildContext context, Text myContent) {
    showCupertinoModalPopup<void>(
      context: context,
      builder: (BuildContext context) => CupertinoAlertDialog(
        content: myContent,
        actions: <CupertinoDialogAction>[
          CupertinoDialogAction(
            isDefaultAction: true,
            onPressed: () {
              Navigator.pop(context);
            },
            child: const Text('Geri dön'),
          ),
        ],
      ),
    );
  }

  void _showAndroidAlert(BuildContext context, Text myContent) {
    showDialog(
      context: context,
      barrierDismissible: true,
      builder: (BuildContext context) {
        return AlertDialog(
          content: myContent,
          //buttons?
          actions: <Widget>[
            TextButton(
              child: const Text("Geri dön"),
              onPressed: () {
                Navigator.of(context).pop();
              }, //closes popup
            ),
          ],
        );
      },
    );
  }

  Future passwordReset() async {
    String resetMail = _emailController.text.toString();

    try {
      await FirebaseAuth.instance
          .sendPasswordResetEmail(email: _emailController.text.trim());
      if (Platform.isIOS) {
        _showIOSAlert(
          context,
          Text('$resetMail adresine şifre sıfırlama linki gönderildi'),
        );
      } else {
        _showAndroidAlert(
          context,
          Text('$resetMail adresine şifre sıfırlama linki gönderildi'),
        );
      }
    } on FirebaseAuthException catch (e) {
      if (Platform.isIOS) {
        return _showIOSAlert(
          context,
          Text(
            e.message.toString(),
          ),
        );
      } else {
        return _showAndroidAlert(
          context,
          Text(
            e.message.toString(),
          ),
        );
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Şifremi Unuttum"),
        elevation: 0,
      ),
      body: SafeArea(
        child: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Container(
                height: 70,
                padding: const EdgeInsets.symmetric(horizontal: 25),
                child: TextField(
                    controller: _emailController,
                    cursorColor: Colors.white,
                    keyboardType: TextInputType.emailAddress,
                    style: const TextStyle(color: Colors.white),
                    decoration: InputDecoration(
                        floatingLabelBehavior: FloatingLabelBehavior.never,
                        hintText: "E-posta",
                        hintStyle: const TextStyle(color: Colors.white),
                        labelStyle: const TextStyle(color: Colors.white),
                        filled: true,
                        fillColor: applicationPurple,
                        border: OutlineInputBorder(
                            borderSide: BorderSide.none,
                            borderRadius: BorderRadius.circular(20)))),
              ),
              Container(
                decoration: BoxDecoration(
                    color: applicationOrange,
                    borderRadius: BorderRadius.circular(20)),
                height: 50,
                padding: const EdgeInsets.symmetric(horizontal: 25.0),
                child: TextButton(
                  onPressed: () {
                    passwordReset();
                  },
                  child: const Text(
                    "Şifremi Sıfırla",
                    style: TextStyle(
                        color: Colors.white, fontWeight: FontWeight.bold),
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

Answer 1

你得到这个异常是因为你只捕获 firebase 异常：

试试这个：

 // ignore_for_file: use_build_context_synchronously
    import 'dart:io';
    import 'package:firebase_auth/firebase_auth.dart';
    import 'package:flutter/cupertino.dart';
    import 'package:flutter/material.dart';
    import 'package:petinonedemo/main.dart';
    
    class ForgotPasswordPage extends StatefulWidget {
      const ForgotPasswordPage({super.key});
    
      @override
      State<ForgotPasswordPage> createState() => _ForgotPasswordPageState();
    }

class _ForgotPasswordPageState extends State<ForgotPasswordPage> {
  final TextEditingController _emailController = TextEditingController();
  final TextEditingController _phoneNumberController = TextEditingController();

  @override
  void dispose() {
    _emailController.dispose();
    _phoneNumberController.dispose();
    super.dispose();
  }

  void _showIOSAlert(BuildContext context, Text myContent) {
    showCupertinoModalPopup<void>(
      context: context,
      builder: (BuildContext context) => CupertinoAlertDialog(
        content: myContent,
        actions: <CupertinoDialogAction>[
          CupertinoDialogAction(
            isDefaultAction: true,
            onPressed: () {
              Navigator.pop(context);
            },
            child: const Text('Geri dön'),
          ),
        ],
      ),
    );
  }

  void _showAndroidAlert(BuildContext context, Text myContent) {
    showDialog(
      context: context,
      barrierDismissible: true,
      builder: (BuildContext context) {
        return AlertDialog(
          content: myContent,
          //buttons?
          actions: <Widget>[
            TextButton(
              child: const Text("Geri dön"),
              onPressed: () {
                Navigator.of(context).pop();
              }, //closes popup
            ),
          ],
        );
      },
    );
  }

  Future passwordReset() async {
    String resetMail = _emailController.text.toString();

    try {
      await FirebaseAuth.instance
          .sendPasswordResetEmail(email: _emailController.text.trim());
      if (Platform.isIOS) {
        _showIOSAlert(
          context,
          Text('$resetMail adresine şifre sıfırlama linki gönderildi'),
        );
      } else {
        _showAndroidAlert(
          context,
          Text('$resetMail adresine şifre sıfırlama linki gönderildi'),
        );
      }
    } on FirebaseAuthException catch (e) {
      if (Platform.isIOS) {
        return _showIOSAlert(
          context,
          Text(
            e.message.toString(),
          ),
        );
      } else {
        return _showAndroidAlert(
          context,
          Text(
            e.message.toString(),
          ),
        );
      }
    } catch (_){
//-------------------------
      print('Generic Auth Exception')
      
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Şifremi Unuttum"),
        elevation: 0,
      ),
      body: SafeArea(
        child: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Container(
                height: 70,
                padding: const EdgeInsets.symmetric(horizontal: 25),
                child: TextField(
                    controller: _emailController,
                    cursorColor: Colors.white,
                    keyboardType: TextInputType.emailAddress,
                    style: const TextStyle(color: Colors.white),
                    decoration: InputDecoration(
                        floatingLabelBehavior: FloatingLabelBehavior.never,
                        hintText: "E-posta",
                        hintStyle: const TextStyle(color: Colors.white),
                        labelStyle: const TextStyle(color: Colors.white),
                        filled: true,
                        fillColor: applicationPurple,
                        border: OutlineInputBorder(
                            borderSide: BorderSide.none,
                            borderRadius: BorderRadius.circular(20)))),
              ),
              Container(
                decoration: BoxDecoration(
                    color: applicationOrange,
                    borderRadius: BorderRadius.circular(20)),
                height: 50,
                padding: const EdgeInsets.symmetric(horizontal: 25.0),
                child: TextButton(
                  onPressed: () {
                    passwordReset();
                  },
                  child: const Text(
                    "Şifremi Sıfırla",
                    style: TextStyle(
                        color: Colors.white, fontWeight: FontWeight.bold),
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}