自定义分组逻辑 [英] Custom grouping logic

问题描述

大家好，

让我说我有这个班级

公共类文章
 {
 public int ID {get; set;} 
 public string Name {get; set;} 
 public int State {get;设置;} 
} 

此测试数据

列表<物品> lst = new List< article>（）; 
 
 
 lst.Add（new article（）{ID = 1，Name =" Item1"，state = 0}）; 
 lst.Add（new article（）{ID = 2，Name =" Item2"，state = 0}）; 
 lst.Add（new article（）{ID = 3，Name =" Item3"，state = 1}）; 
 lst.Add（new article（）{ID = 4，Name =" Item4"，state = 1}）; 
 lst.Add（new article（）{ID = 5，Name =" Item5"，state = 2}）; 
 lst.Add（new article（）{ID = 6，Name =" Item6"，state = 2}）; 
 lst.Add（new article（）{ID = 7，Name =" Item7"，state = 3}）; 

我想拥有一组3组的分组：

组1：其中state = 0或1

第2组： WHere state = 2

第3组：其中state = 3

这只是一个简单的测试用例，但我希望能够控制分组标准条件

谢谢。

解决方案

你好issam1975，

根据你的描述，我建议你可以将记录填入另一个对象，然后由它组成。您引用的以下代码。

 class Program 
 {
 static void Main（string [] args）
 {
 List< article> lst = new List< article>（）; 
 
 lst.Add（new article（）{ID = 1，Name =" Item1"，State = 0}）; 
 lst.Add（new article（）{ID = 2，Name =" Item2"，State = 0}）; 
 lst.Add（new article（）{ID = 3，Name =" Item3"，State = 1}）; 
 lst.Add（new article（）{ID = 4，Name =" Item4"，State = 1}）; 
 lst.Add（new article（）{ID = 5，Name =" Item5"，State = 2}）; 
 lst.Add（new article（）{ID = 6，Name =" Item6"，State = 2}）; 
 lst.Add（new article（）{ID = 7，Name =" Item7"，State = 3}）; 
 
 var dtos = lst.Select（t => new articleDto（）
 {
 ID = t.ID，
 Name = t.Name，
 State = t.State，
 GroupState =（t.State == 0 || t.State == 1）？0：t.State 
}）。ToList（）; 
 
 // group by here 
 var groupResult = dtos.GroupBy（t => t.GroupState）.Select（t => new {key = t.Key，count = t .Count（）}）; 
 
 
 
 Console.ReadLine（）; 
} 
} 
 
公共类文章
 {
 public int ID {get;组; } 
 public string Name {get;组; } 
 public int State {get;组; } 
} 
 
公共类文章D 
 {
 public int ID {get;组; } 
 public string Name {get;组; } 
 public int State {get;组; } 
 public int GroupState {get;组; } 
} 

祝你好运，

张龙

hi everyone,

let's say that i have this class

public class article
{
   public int ID {get; set;}
   public string Name {get; set;}
   public int State {get; set;}
}

and this test data

List<article> lst = new List<article>();


lst.Add(new article(){ID= 1, Name="Item1", state=0});
lst.Add(new article(){ID= 2, Name="Item2", state=0});
lst.Add(new article(){ID= 3, Name="Item3", state=1});
lst.Add(new article(){ID= 4, Name="Item4", state=1});
lst.Add(new article(){ID= 5, Name="Item5", state=2});
lst.Add(new article(){ID= 6, Name="Item6", state=2});
lst.Add(new article(){ID= 7, Name="Item7", state=3});

i want to have a grouped collection with 3 groups :

Group 1: where state= 0 or 1

Group 2 : WHere state = 2

Group 3 : where state = 3

this just a simple test case but i want to be able to control the grouping criteria condition

thanks .

解决方案

Hi issam1975,

According to your description, I would suggest that you could fill the records into another object, then group by it. the following code for you reference.

class Program
    {
        static void Main(string[] args)
        {
            List<article> lst = new List<article>();

            lst.Add(new article() { ID = 1, Name = "Item1", State = 0 });
            lst.Add(new article() { ID = 2, Name = "Item2", State = 0 });
            lst.Add(new article() { ID = 3, Name = "Item3", State = 1 });
            lst.Add(new article() { ID = 4, Name = "Item4", State = 1 });
            lst.Add(new article() { ID = 5, Name = "Item5", State = 2 });
            lst.Add(new article() { ID = 6, Name = "Item6", State = 2 });
            lst.Add(new article() { ID = 7, Name = "Item7", State = 3 });

            var dtos = lst.Select(t => new articleDto()
            {
                ID = t.ID,
                Name = t.Name,
                State = t.State,
                GroupState = (t.State == 0 || t.State == 1) ? 0 : t.State
            }).ToList();

            // group by here
            var groupResult = dtos.GroupBy(t => t.GroupState).Select(t => new { key = t.Key,count = t.Count() });

            

            Console.ReadLine();
        }
    }

    public class article
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public int State { get; set; }
    }

    public class articleDto
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public int State { get; set; }
        public int GroupState { get; set; }
    }

Best regards,

Zhanglong

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