MVC为模型增加正则表达式

 [Required(ErrorMessage = "密码不能为空"), RegularExpression(@"^(?=.*\d)(?=.*[a-z]).{6,18}$", ErrorMessage = "必须包含小字母和数字")]
        [StringLength(100, ErrorMessage = "{0} 至少包含 {2} 个字符。", MinimumLength = 6)]
        [DataType(DataType.Password)]
        [Display(Name = "密码")]
        public string Password { get; set; }