我如何解决 flutter class 代码中的这个错误

Question

我写这个class

class Profile {
  String email;
  String password;

  Profile({this.email, this.password});
}

但是它说

"The parameter 'email' can't have a value of 'null' because of its type, but the implicit default value is 'null'.
Try adding either an explicit non-'null' default value or the 'required' modifier.dartmissing_default_value_for_parameter"

Answer 1

通过添加要求：

class Profile {
  String email;
  String password;

  Profile({
    required this.email,
    required this.password,
  });
}

通过添加可选：

class Profile {
  String? email;
  String? password;

  Profile({
    this.email,
    this.password,
  });
}

通过添加默认值：

class Profile {
  String email;
  String password;

  Profile({
    this.email = "mail@gmail.com",
    this.password = "123",
  });
}

Answer 2

您必须让他们接受一个 null 值。

class Profile {
  String? email;
  String? password;

  Profile({this.email, this.password});
}

我如何解决 flutter class 代码中的这个错误

How can I solved this error in flutter class code

class

dart

flutter