ASP.net Core 3 IdentityErrorDescriber 错误消息

Question

我有一个 ASP.net Core 3.1 Web 应用程序。 我正在尝试在创建新用户时自定义“无效用户名”的错误消息。 我创建了一个自定义类“CustomIdentityErrorDescriber”，它继承了 Microsoft.AspNetCore.Identity.IdentityErrorDescriber

public class CustomIdentityErrorDescriber : IdentityErrorDescriber
  {
        public override IdentityError DefaultError() { return new IdentityError { Code = nameof(DefaultError), Description = $"An unknown failure has occurred." }; }
        public override IdentityError ConcurrencyFailure() { return new IdentityError { Code = nameof(ConcurrencyFailure), Description = "Optimistic concurrency failure, object has been modified." }; }
        public override IdentityError PasswordMismatch() { return new IdentityError { Code = nameof(PasswordMismatch), Description = "Incorrect password." }; }
        public override IdentityError InvalidToken() { return new IdentityError { Code = nameof(InvalidToken), Description = "Invalid token." }; }
        public override IdentityError LoginAlreadyAssociated() { return new IdentityError { Code = nameof(LoginAlreadyAssociated), Description = "A user with this login already exists." }; }
        public override IdentityError InvalidUserName(string userName) { return new IdentityError { Code = nameof(InvalidUserName), Description = $"User name '{userName}' is invalid, allowable characters 'a-z 'A-Z'." }; }
        public override IdentityError InvalidEmail(string email) { return new IdentityError { Code = nameof(InvalidEmail), Description = $"Email '{email}' is invalid." }; }
        public override IdentityError DuplicateUserName(string userName) { return new IdentityError { Code = nameof(DuplicateUserName), Description = $"User Name '{userName}' is already taken." }; }
        public override IdentityError DuplicateEmail(string email) { return new IdentityError { Code = nameof(DuplicateEmail), Description = $"Email '{email}' is already taken." }; }
        public override IdentityError InvalidRoleName(string role) { return new IdentityError { Code = nameof(InvalidRoleName), Description = $"Role name '{role}' is invalid." }; }
        public override IdentityError DuplicateRoleName(string role) { return new IdentityError { Code = nameof(DuplicateRoleName), Description = $"Role name '{role}' is already taken." }; }
        public override IdentityError UserAlreadyHasPassword() { return new IdentityError { Code = nameof(UserAlreadyHasPassword), Description = "User already has a password set." }; }
        public override IdentityError UserLockoutNotEnabled() { return new IdentityError { Code = nameof(UserLockoutNotEnabled), Description = "Lockout is not enabled for this user." }; }
        public override IdentityError UserAlreadyInRole(string role) { return new IdentityError { Code = nameof(UserAlreadyInRole), Description = $"User already in role '{role}'." }; }
        public override IdentityError PasswordTooShort(int length) { return new IdentityError { Code = nameof(PasswordTooShort), Description = $"Passwords must be at least {length} characters." }; }
        public override IdentityError PasswordRequiresNonAlphanumeric() { return new IdentityError { Code = nameof(PasswordRequiresNonAlphanumeric), Description = "Passwords must have at least one non alphanumeric character." }; }
        public override IdentityError PasswordRequiresDigit() { return new IdentityError { Code = nameof(PasswordRequiresDigit), Description = "Passwords must have at least one digit ('0'-'9')." }; }
        public override IdentityError PasswordRequiresLower() { return new IdentityError { Code = nameof(PasswordRequiresLower), Description = "Passwords must have at least one lowercase ('a'-'z')." }; }
        public override IdentityError PasswordRequiresUpper() { return new IdentityError { Code = nameof(PasswordRequiresUpper), Description = "Passwords must have at least one uppercase ('A'-'Z')." }; }
    }

我已经在 startup.cs 文件中实现了我的自定义类，如下所示

services.AddTransient<IdentityErrorDescriber, CustomIdentityErrorDescriber>();

            services.Configure<IdentityOptions>(opts =>
            {
                // opts.User.RequireUniqueEmail = true;
                opts.User.AllowedUserNameCharacters =
                        "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-._";
                 opts.Password.RequiredLength = 8;
                opts.Password.RequireNonAlphanumeric = false;
                opts.Password.RequireLowercase = false;
                opts.Password.RequireUppercase = false;
                opts.Password.RequireDigit = false;
            
            });

该错误是由代码检测到的，我确实从框架中收到了一条错误消息。 但是，错误消息包含有关对我来说毫无意义的角色的措辞。 所以显示给用户的错误消息在弹出对话框中是

“用户已经在角色用户名‘xxx xxx’无效，允许使用字符‘az’A-Z’。”

在错误消息的正确最后部分之前有“用户已经在角色中”的位置和原因超出了我的理解。

Answer 1

由于您创建了IdentityErroDescriber的扩展，您还必须通知 Identity 将右侧直接指向您的新扩展方法。

这是通过在startup.cs 中的ConfigureServices方法中提供身份注册上的扩展方法来实现的：

services.AddIdentity<AppUser, AppRole>()
        .AddErrorDescriber<CustomIdentityErrorDescriber>(); //<== Here

这样，所有错误都将按照您的扩展方法中的描述显示。