自制AutoMapper实现DTO到持久层Entity的转换

自制AutoMapper实现DTO到持久层Entity的转换

项目中经常涉及到页面DTO更新，保存到数据库的操作，这就必然牵扯到DTO和持久层对象的转换，常见的第三方库有：

java：dozer

.net: AutoMapper

看到AutoMapper已经许久没更新了，而且项目中没必要用这么大的东西，于是自己实现了一个简易DTO到Entity的转换器。

实现的功能
自定义的AutoMapper主要实现了如下几点功能：

1.DTO字段忽略转换

[AutoMapping(Ignore=true)]
public DateTime CreateTime { get; set; }

2.DTO字段和Entity的强制映射

[AutoMapping(EntityColumn="Sex")]
public string XingBie { get; set; }

3.默认DTO和Entity字段相同的，自动转换

核心代码:

using System;
using System.Collections.Generic;
using System.Reflection;
using System.Text;
using System.Linq;

namespace ElegantWM.AutoMapper
{
public class AutoMapper<T1,T2> where T1:new() where T2:new()
{
/// <summary>
/// DTO 转换为 Entity
/// </summary>
/// <typeparam name="T1">DTO</typeparam>
/// <typeparam name="T2">Entity</typeparam>
/// <param name="t1">Dto</param>
/// <param name="t2">Entity</param>
/// <returns></returns>
public static T2 Convert(T1 t1, T2 t2)
{
var dtoProperList = t1.GetType().GetProperties().Where(p => p.PropertyType.IsPublic == true).ToList();
var entityProperList = t2.GetType().GetProperties().Where(p => p.PropertyType.IsPublic == true).ToList();
foreach (System.Reflection.PropertyInfo pi in dtoProperList)
{
string realName=pi.Name;
//首先判断列是否ignore？,是否含有Column
object[] cusAttrs = pi.GetCustomAttributes(typeof(AutoMappingAttribute), true);
if (cusAttrs.Length > 0)
{
AutoMappingAttribute attr = cusAttrs[0] as AutoMappingAttribute;
if (attr.Ignore)
continue;
if (!string.IsNullOrEmpty(attr.EntityColumn))
realName = attr.EntityColumn;
}
var entityPi = entityProperList.Single(p => p.Name == realName);
if (entityPi == null)
continue;
object value = pi.GetValue(t1, null);
if (value == null)
continue;
entityPi.SetValue(t2, value, null);
}
return t2;
}
}
}

案例
持久层Entity的定义如下：

public class Entity:IEntity
{
public Guid Id { get; set; }
public string CreateUser { get; set; }
public DateTime CreateTime { get; set; }
public string ModifyUser { get; set; }
public DateTime? ModifyTime { get; set; }
[Timestamp]
public Byte[] RowVersion { get; set; }
}
public class WMS_User : Entity
{
public WMS_User() { }

public string UserName { get; set; }
public string NickName { get; set; }
public string UserPwd { get; set; }
public string Sex { get; set; }
public string Phone { get; set; }
public string Email { get; set; }
public string QQ { get; set; }
public string Address { get; set; }
public string Remark { get; set; }
public bool Disable { get; set; }
public virtual ICollection<WMS_OrgUser> UserOrgIds { get; set; }
}

页面DTO定义如下：

public class UserDto
{
public UserDto() { }
public Guid Id { get; set; }
public string UserName { get; set; }
public string NickName { get; set; }
public string UserPwd { get; set; }
//强制字段映射
[AutoMapping(EntityColumn="Sex")]
public string XingBie { get; set; }

public string Phone { get; set; }
public string Email { get; set; }
public string QQ { get; set; }
public string Address { get; set; }
public string Remark { get; set; }
public bool Disable { get; set; }
//忽略字段映射
[AutoMapping(Ignore=true)]
public DateTime CreateTime { get; set; }
}    

使用AutoMapper，做转换：

　　　　 [Action]
[Description("更新用户")]
[HttpPut]
public JsonResult Update(UserDto user)
{
WMS_User userEntity = WMFactory.WMSUser.GetById(user.Id.ToString());
//*******看这里哦********
userEntity = AutoMapper<UserDto, WMS_User>.Convert(user, userEntity);
if (WMFactory.WMSUser.Update(userEntity))
return Json(ResultMsg.Success("用户信息更新成功！"));
else
return Json(ResultMsg.Failure("用户信息更新失败，请您重试！"));
}

写在后面
自己实现，相对来说，自由度高了很多，你可以自己扩展方法，实现客制化的DTO转Entity，让AutoMapper更加适合自己的项目。