asp.net mvc3 数据验证（三）—自定义数据注解

        [Required(ErrorMessageResourceType=typeof(ErrorMessage),ErrorMessageResourceName="UserRequire")]
        [Display(Name = "用户名")]
        [MyMaxLengthAttribute(10,ErrorMessage="{0}字数太多")]
        [Remote("CheckUserName","Account", HttpMethod="POST")]
        public string UserName { get; set; }

    public class MyMaxLengthAttribute : ValidationAttribute
    {
        private readonly int MaxLength;
 
        public MyMaxLengthAttribute(int maxLength ):base("{0}的字符太多了!")
        {
            MaxLength = maxLength;
        }
 
        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
        {
            string content = value.ToString();
            if (content.Length > MaxLength)
            {
                //return new ValidationResult("输入的字符太多了！^_^");
                string errorMessage = FormatErrorMessage(validationContext.DisplayName); 
                return new ValidationResult(errorMessage);
            }
            return ValidationResult.Success;
            //return base.IsValid(value, validationContext);
        }
    }

        public IEnumerable<ValidationResult> Validate(ValidationContext validationContent)
        {
            if (Password != ConfirmPassword)
            {
                yield return new ValidationResult("两次输入的密码不同！", new[] { "Password" });
            }
        }