Flutter：是否有更好的方法来处理if / else语句中每个条件的setState调用？

问题描述

我有未优化的代码。基本上，如果发生FirebaseAuthException，我想更改errorString的值。我该使用ChangeNotifier吗？

Future<void> _signInWithEmailAndPassword(BuildContext context,AsyncSnapshot<String> usersnapshot,AsyncSnapshot<String> passwordSnapshot) async {
    try {
      final auth = Provider.of<AuthService>(context,listen: false);
      await auth.signInWithEmailAndPassword(
          usersnapshot.data.trim(),passwordSnapshot.data.trim());
          setState(() => errorString = 'Success');
    } on FirebaseAuthException catch (e) {
      // I don't want to call setState() in each condition
      if (e.code == 'invalid-credential') {
        setState(() {
          errorString = "Email address appears to be malformed/expired";
        });
      } else if (e.code == 'wrong-password') {
        setState(() {
          errorString = "Password associated with this email is wrong";
        });
      } else if (e.code == 'user-not-found') {
        setState(() {
          errorString = "Email has not been registered,please sign up :)";
        });
      } else if (e.code == 'user-disabled') {
        setState(() {
          errorString = "User with this email has been disabled :(";
        });
      } else if (e.code == 'too-many-requests') {
        setState(() {
          errorString = "Too many requests,please try again later.";
        });
      } else if (e.code == 'operation-not-allowed') {
        setState(() {
          errorString = "Signing in with email and password is not enabled";
        });
      } else if (e.code == 'account-exists-with-different-credential') {
        setState(() {
          errorString =
              "Email has already been registered. Reset your password.";
        });
      }
    } 
  }

解决方法

我会做这样的事情：

const errMap = {
    'invalid-credential': "Email address appears to be malformed/expired",'wrong-password': "Password associated with this email is wrong",'user-not-found': "Email has not been registered,please sign up :)",'user-disabled': "User with this email has been disabled :(",'too-many-requests': "Too many requests,please try again later.",'operation-not-allowed': "Signing in with email and password is not enabled",'account-exists-with-different-credential': "Email has already been registered. Reset your password."
};

setState(() {
    errorString = errMap[e.code];
});

,

只需将getDaysInMonth(1,2020)放在所有喜欢的结尾

setState