类字段属性自动验证

1.验证特性定义

[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
    public class CountryAttribute : ValidationAttribute
    {
        public string AllowCountry { get; set; }
        /// <summary>
        /// 验证数据是否合法
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        public override bool IsValid(object value)
        {
            return string.Equals(value, AllowCountry);
        }
        /// <summary>
        /// 验证结果
        /// </summary>
        /// <param name="value"></param>
        /// <param name="validationContext"></param>
        /// <returns></returns>
        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
        {
            if (string.Equals(value, AllowCountry))
                return ValidationResult.Success;
            else
                return new ValidationResult(string.Format("{0}-{1}-{2} 字段非法", validationContext.DisplayName, validationContext.MemberName, ErrorMessage), new[] { validationContext.MemberName });
        }
    }//end

2.类属性定义

public class test
    {
        /// <summary>
        /// 姓名1
        /// </summary>
        [CountryAttribute(AllowCountry = "fhc", ErrorMessage = "自定义错误1"), Display(Name = "姓名")]
        public string name { set; get; }
        [CountryAttribute(AllowCountry = "fhc2", ErrorMessage = "自定义错误2"), Display(Name = "姓名2")]
        public string name2 { set; get; }
        [Range(10, 70, ErrorMessage = "自定义错误")]
        public int age { set; get; }

    }//end

3.验证结果方法

/// <summary>
        /// 错误列表
        /// </summary>
        /// <param name="o"></param>
        /// <returns></returns>
        public List<string> ErrorList(object o)
        {
            List<string> list = new List<string>();
            var context = new ValidationContext(o, null, null);

            var results = new List<ValidationResult>();
            Validator.TryValidateObject(o, context, results, true);

            foreach (var validationResult in results)
            {
                list.Add(validationResult.ErrorMessage);
            }
            return list;
        }

4.实际使用

 test t = new test()
            {
                age = 0,
                name = "fan"
            };
            List<string> list = ErrorList(t);

如果list长度为0则表示没有错误，否则则是错误列表。