最近公司开发项目前端使用一个js框架，后端使用ef，js前台读取的json采用实体的dto来进行生成。
在网上看到了EmitMapper相对其他映射框架处理速度可以更快，就拿来用了。下面是代码中常用的几个块。
1.普通的映射。
public class UserInfo
{
public int id { get; set; }
public string name { get; set; }
public string address { get; set; }
}
public class UserInfoDTO
{
public string name { get; set; }
public string address { get; set; }
}
var mapper = ObjectMapperManager.DefaultInstance.GetMapper<UserInfo, UserInfoDTO>();
UserInfoDTO userdto = mapper.Map(user);
2.有外键关联，需要映射出外键所带名字
public class UserInfo
{
public int id { get; set; }
public string name { get; set; }
public string address { get; set; }
public Teacher teacher { get; set; }
}
public class Teacher
{
public int id { get; set; }
public string name { get; set; }
}
public class UserInfoDTO
{
public int id { get; set; }
public string name { get; set; }
public string teacher { get; set; }
}
var user = new UserInfo {
id = 12,
name = "张三",
address = "北京",
teacher = new Teacher {
id = 11,
name = "王五"
}
};
var mapper = ObjectMapperManager.DefaultInstance.GetMapper<UserInfo, UserInfoDTO>(
new DefaultMapConfig()
.ConvertUsing<Teacher, string>(t => t.name)
);
UserInfoDTO userdto = mapper.Map(user);
3.两个实体之间名字不一致，需要映射。
public class UserInfo
{
public int id { get; set; }
public string name { get; set; }
public string address { get; set; }
}
public class UserInfoDTO
{
public int id { get; set; }
public string name { get; set; }
public string userAddress { get; set; }
}
var mapper = ObjectMapperManager.DefaultInstance.GetMapper<UserInfo, UserInfoDTO>(
new DefaultMapConfig()
.MatchMembers((x, y) =>
{
if (x == "address" && y == "userAddress")
{
return true;
}
return x == y;
})
);
UserInfoDTO userdto = mapper.Map(user);
4.需要对某一个字段进行特殊处理
public class UserInfo
{
public int id { get; set; }
public string name { get; set; }
public string address { get; set; }
}
public class UserInfoDTO
{
public string id { get; set; }
public string name { get; set; }
public string userAddress { get; set; }
public string userJson { get; set; }
}
var user = new UserInfo {
id = 12,
name = "张三",
address = "北京"
};
var mapper = ObjectMapperManager.DefaultInstance.GetMapper<UserInfo, UserInfoDTO>(
new DefaultMapConfig()
.PostProcess<UserInfoDTO>((value, state) =>
{
//在id编号前加上今年的年份
value.id = DateTime.Now.ToString("yyyy") + value.id;
//实体的json格式
value.userJson = "{\"id\":\"" + value.id + "\",\"name\":\"" + value.name + "\"}";
return value;
})
);
UserInfoDTO userdto = mapper.Map(user);
5.忽略掉某个字段的映射
public class UserInfo
{
public int id { get; set; }
public string name { get; set; }
public string address { get; set; }
}
public class UserInfoDTO
{
public string id { get; set; }
public string name { get; set; }
public string address { get; set; }
}
var user = new UserInfo {
id = 12,
name = "张三",
address = "北京"
};
var mapper = ObjectMapperManager.DefaultInstance.GetMapper<UserInfo, UserInfoDTO>(
new DefaultMapConfig()
.IgnoreMembers<UserInfo, UserInfoDTO>(new string[] { "name" })
);
UserInfoDTO userdto = mapper.Map(user);
6.给空元素赋默认值
public class UserInfo
{
public int id { get; set; }
public string name { get; set; }
public string address { get; set; }
public DateTime? godate { get; set; }
}
public class UserInfoDTO
{
public string id { get; set; }
public string name { get; set; }
public string address { get; set; }
public DateTime godate { get; set; }
}
var user = new UserInfo {
id = 12,
name = "张三",
address = null,
godate = null
};
var mapper = ObjectMapperManager.DefaultInstance.GetMapper<UserInfo, UserInfoDTO>(
new DefaultMapConfig()
//如果日期为空设置为当前时间
.NullSubstitution<DateTime?, DateTime>((value) => DateTime.Now)
//如果string类型为null赋值为“”
.NullSubstitution<string, string>((value) => "")
);
UserInfoDTO userdto = mapper.Map(user);
常用的就上面几点，对于更深入的。有待以后研究。。。。。