使用LINQ to组对象的列表 [英] Using LINQ to group a list of objects

问题描述

我有一个对象：

 公共类客户
 {
公众诠释ID {搞定;组; } 
公共字符串名称{;组; } 
公众诠释组ID {搞定;组; } 
} 
  

我返回一个列表可能如下所示：

 列表<客户> CustomerList =新的List<客户>（）; 
 CustomerList.Add（新客户{ID = 1，名称=一，组ID = 1}）; 
 CustomerList.Add（新客户{ID = 2，名称=二，组ID = 1}）; 
 CustomerList.Add（新客户{ID = 3，名称=三公，组ID = 2}）; 
 CustomerList.Add（新客户{ID = 4，名称=四，组ID = 1}）; 
 CustomerList.Add（新客户{n = 5，名称=五个一，组ID = 3}）; 
 CustomerList.Add（新客户{ID = 6，名称=六个一，组ID = 3}）; 
  

我要回LINQ查询它看起来像

  CustomerList 
组ID = 1 
用户ID = 1，用户名=UserOne，组ID = 1 
用户ID = 2，用户名= UserTwo，组ID = 1 
用户ID = 4，用户名=UserFour，组ID = 1 
组ID = 2 
用户ID = 3，用户名=UserThree，组ID = 2 
组ID = 3 
用户id = 5，用户名=UserFive，组ID = 3 
用户ID = 6，用户名=UserSix，
  

我从

试图

的使用LINQ到组的对象的列表成列表的新分组的列表对象

代码

  VAR groupedCustomerList = CustomerList 
 .GroupBy（U => u.GroupID）
。选择（GRP => grp.ToList（））
 .ToList（）; 
  

的作品，但是没有得到所需的输出。

解决方案

  VAR groupedCustomerList = CustomerList.GroupBy（U => u.GroupID）
。选择（GRP =>新建{组ID = grp.Key，CustomerList = grp.ToList（）}）
 .ToList（）; 
  

I have an object:

public class Customer
{
    public int ID { get; set; }
    public string Name { get; set; }
    public int GroupID { get; set; }
}

I return a list that may look like the following:

List<Customer> CustomerList = new List<Customer>();
CustomerList.Add( new Customer { ID = 1, Name = "One", GroupID = 1 } );
CustomerList.Add( new Customer { ID = 2, Name = "Two", GroupID = 1 } );
CustomerList.Add( new Customer { ID = 3, Name = "Three", GroupID = 2 } );
CustomerList.Add( new Customer { ID = 4, Name = "Four", GroupID = 1 } );
CustomerList.Add( new Customer { ID = 5, Name = "Five", GroupID = 3 } );
CustomerList.Add( new Customer { ID = 6, Name = "Six", GroupID = 3 } );

I want to return a linq query which will look like

CustomerList
  GroupID =1
    UserID = 1, UserName = "UserOne", GroupID = 1
    UserID = 2, UserName = "UserTwo", GroupID = 1
    UserID = 4, UserName = "UserFour", GroupID = 1
  GroupID =2
    UserID = 3, UserName = "UserThree", GroupID = 2
  GroupID =3
    UserID = 5, UserName = "UserFive", GroupID = 3
    UserID = 6, UserName = "UserSix",

I tried from

Using Linq to group a list of objects into a new grouped list of list of objects

code

var groupedCustomerList = CustomerList
  .GroupBy(u => u.GroupID)
  .Select(grp => grp.ToList())
  .ToList();

works but does not give the desired output.

解决方案

var groupedCustomerList = CustomerList.GroupBy(u => u.GroupID)
                                      .Select(grp =>new { GroupID =grp.Key, CustomerList = grp.ToList()})
                                      .ToList();

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