使用LINQ获取List列表中的某个字段值

1 List<Emplayee> emplayeeList = GetEmplayeeList();            //获取员工信息列表  
2 int[] empIds = emplayeeList.Select(a => a.Id).ToArray();    //获取员工编号数组  

1 List<Emplayee> emplayeeList = GetEmplayeeList();  //获取员工信息列表  
2 string empIds = "";  
3 emplayeeList.ForEach(a => empIds += a.Id + ",");  
4 empIds = empIds.TrimEnd(',');  
5 Console.WriteLine(empIds);   //输出：1,2,3  

 1 /// <summary>    
 2 /// 员工信息类    
 3 /// </summary>    
 4 public class Emplayee  
 5 {  
 6     /// <summary>  
 7     /// 编号  
 8     /// </summary>  
 9     public int Id { get; set; }  
10   
11     /// <summary>    
12     /// 姓名    
13     /// </summary>    
14     public string Name { get; set; }  
15 } 
16 
17 
18 /// <summary>    
19 /// 获取员工信息列表    
20 /// </summary>    
21 /// <returns></returns>    
22 public static List<Emplayee> GetEmplayeeList()  
23 {  
24     List<Emplayee> emplayeeList = new List<Emplayee>();  
25     Emplayee emplayee1 = new Emplayee() { Id = 1, Name = "张三" };  
26     Emplayee emplayee2 = new Emplayee() { Id = 2, Name = "李四" };  
27     Emplayee emplayee3 = new Emplayee() { Id = 3, Name = "王五" };  
28     emplayeeList.Add(emplayee1);  
29     emplayeeList.Add(emplayee2);  
30     emplayeeList.Add(emplayee3);  
31     return emplayeeList;  
32 }