模型/数据验证（System.ComponentModel.DataAnnotations）笔记

1.

、、

2.案例：（具体参照：https://www.jianshu.com/p/ca44d2ffa974）

Models：

using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;

namespace WebApplication1.Models
{

    public class UserModel
    {
        [Required(ErrorMessage = "{0} 必须填写")]  // 必须
        public string UserID { get; set; }

        /// <summary>
        /// 姓名
        /// </summary>
        [MaxLength(10, ErrorMessage = "超出字符长度")]
        [MinLength(2, ErrorMessage = "最短字符长度为2")]
        public string UserName { get; set; }

        /// <summary>
        /// 年龄
        /// </summary>
        [Required(ErrorMessage = "{0} 必须填写")]
        [Range(18, 100)]
        public int Age { get; set; }

        /// <summary>
        /// 性别：1表示男,2表示女
        /// </summary>
        [RegularExpression(@"[1|2]+", ErrorMessage = "性别不正确")]  // 正则规则
        public int Sex { get; set; }
    }
    public class ValidResult
    {
        public List<ErrorMember> ErrorMembers { get; set; }
        public bool IsVaild { get; set; }
    }

    public class ErrorMember
    {
        public string ErrorMessage { get; set; }
        public string ErrorMemberName { get; set; }
    }
}

逻辑层处理：

        /// <summary>
        /// 逻辑处理
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        private static ValidResult IsValid(object value)
        {
            ValidResult result = new ValidResult();
            try
            {
                var validationContext = new ValidationContext(value);
                var results = new List<ValidationResult>();
                var isValid = Validator.TryValidateObject(value, validationContext, results, true);

                if (!isValid)
                {
                    result.IsVaild = false;
                    result.ErrorMembers = new List<ErrorMember>();
                    foreach (var item in results)
                    {
                        result.ErrorMembers.Add(new ErrorMember()
                        {
                            ErrorMessage = item.ErrorMessage,
                            ErrorMemberName = item.MemberNames.FirstOrDefault()
                        });
                    }
                }
                else
                {
                    result.IsVaild = true;
                }
            }
            catch (Exception ex)
            {
                result.IsVaild = false;
                result.ErrorMembers = new List<ErrorMember>();
                result.ErrorMembers.Add(new ErrorMember()
                {
                    ErrorMessage = ex.Message,
                    ErrorMemberName = "Internal error"
                });
            }

            return result;
        }

验证失败处理（可以逻辑层验证封装成一个静态类）：

 #region 逻辑处理
            UserModel person = new UserModel();
            person.UserID = "";
            person.UserName = "K";
            person.Age = 100000;
            person.Sex = 3000;
            var result = IsValid(person);
            if (!result.IsVaild)
            {
                // 验证失败处理
                foreach (ErrorMember errorMember in result.ErrorMembers)
                {
                    Console.WriteLine(errorMember.ErrorMemberName + "：" + errorMember.ErrorMessage);
                }
            }
            #endregion