如何自定义 Asp.net Identity 2 用户名已获取验证消息?

好吧，我没有找到任何简单的解决方案.简单地说，我的意思是修改属性/模型/控制器中的一些消息.

Well, I didn't find any simple solution to this issue. And by simple i mean modifying some message in a attribute/model/controller.

一种可能的解决方案是:

One possible solution could be:

执行后

var result = await UserManager.CreateAsync(user, model.Password);

如果结果不成功，您可以检查名称 XYZ 已被占用"的错误属性.模式并将其替换为您的自定义消息.

In case that result is not successful you can check it's Errors property for the "Name XYZ is already taken." pattern and replace it with your custom message.

另一种解决方案(这是我的首选方式)是编写一个自定义的 UserValidation 类:

Another solution (this is my preferred way) is to write a custom UserValidation class:

 /// <summary>
    ///     Validates users before they are saved to an IUserStore
    /// </summary>
    /// <typeparam name="TUser"></typeparam>
    public class CustomUserValidator<TUser> : UserValidator<TUser, string>
        where TUser : ApplicationUser
    {
        /// <summary>
        ///     Constructor
        /// </summary>
        /// <param name="manager"></param>
        public CustomUserValidator(UserManager<TUser, string> manager) : base(manager)
        {
            this.Manager = manager;
        }

        private UserManager<TUser, string> Manager { get; set; }

        /// <summary>
        ///     Validates a user before saving
        /// </summary>
        /// <param name="item"></param>
        /// <returns></returns>
        public override async Task<IdentityResult> ValidateAsync(TUser item)
        {
            if (item == null)
            {
                throw new ArgumentNullException("item");
            }
            var errors = new List<string>();
            await ValidateUserName(item, errors);
            if (RequireUniqueEmail)
            {
                await ValidateEmail(item, errors);
            }
            if (errors.Count > 0)
            {
                return IdentityResult.Failed(errors.ToArray());
            }
            return IdentityResult.Success;
        }

        private async Task ValidateUserName(TUser user, List<string> errors)
        {
            if (string.IsNullOrWhiteSpace(user.UserName))
            {
                errors.Add(String.Format(CultureInfo.CurrentCulture, Resources.PropertyTooShort, "Name"));
            }
            else if (AllowOnlyAlphanumericUserNames && !Regex.IsMatch(user.UserName, @"^[A-Za-z0-9@_.]+$"))
            {
                // If any characters are not letters or digits, its an illegal user name
                errors.Add(String.Format(CultureInfo.CurrentCulture, Resources.InvalidUserName, user.UserName));
            }
            else
            {
                var owner = await Manager.FindByNameAsync(user.UserName);
                if (owner != null && !EqualityComparer<string>.Default.Equals(owner.Id, user.Id))
                {
                    errors.Add(String.Format(CultureInfo.CurrentCulture, Resources.DuplicateName, user.UserName));
                }
            }
        }

        // make sure email is not empty, valid, and unique
        private async Task ValidateEmail(TUser user, List<string> errors)
        {
            if (!user.Email.IsNullOrWhiteSpace())
            {
                if (string.IsNullOrWhiteSpace(user.Email))
                {
                    errors.Add(String.Format(CultureInfo.CurrentCulture, Resources.PropertyTooShort, "Email"));
                return;
                }
                try
                {
                    var m = new MailAddress(user.Email);
                }
                catch (FormatException)
                {
                    errors.Add(String.Format(CultureInfo.CurrentCulture, Resources.InvalidEmail, email));
                return;
                }
            }
            var owner = await Manager.FindByEmailAsync(user.Email);
            if (owner != null && !EqualityComparer<string>.Default.Equals(owner.Id, user.Id))
            {
                errors.Add(String.Format(CultureInfo.CurrentCulture, Resources.DuplicateEmail, email));
            }
        }
    }

您可以看到正在使用的所有验证错误消息资源，因此通过在您的资源中指定自定义格式，您将能够自定义这些消息.

You can see that for all the validation error messages Resources being used, So by specifying a custom format in your resources you will be able to customize those messages.

您可以在ApplicationUserManager 类，Create 方法中注册您的验证器:

You can register your validator in ApplicationUserManager class, Create method:

public static ApplicationUserManager Create(IdentityFactoryOptions<ApplicationUserManager> options, IOwinContext context) 
{
   manager.UserValidator = new CustomUserValidator<ApplicationUser>(manager)
   {
       AllowOnlyAlphanumericUserNames = false,
       RequireUniqueEmail = true
   };
}