C#: Comment convertir une liste d'objets en liste d'une seule propriété de cet objet?

Question

Dire que j'ai:

IList<Person> people = new List<Person>(); 

Et l'objet personne a des propriétés telles que FirstName, LastName, et le sexe.

Comment puis-je convertir ceci en une liste de propriétés de l'objet Person. Par exemple, à une liste de prénoms.

IList<string> firstNames = ??? 

Answer 1

List<string> firstNames = people.Select(person => person.FirstName).ToList(); 

Et avec le tri

List<string> orderedNames = people.Select(person => person.FirstName).OrderBy(name => name).ToList(); 

Answer 2

firstNames = (from p in people select p=>p.firstName).ToList(); 

Answer 3

IList<string> firstNames = (from person in people select person.FirstName).ToList(); 

Ou

IList<string> firstNames = people.Select(person => person.FirstName).ToList(); 

Answer 4

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
namespace TestProject 
{ 
    public partial class WebForm3 : System.Web.UI.Page 
    { 
     protected void Page_Load(object sender, EventArgs e) 
     { 
      SampleDataContext context = new SampleDataContext(); 
      List<Employee> l = new List<Employee>(); 
      var qry = from a in context.tbl_employees where a.Gender=="Female" 
       orderby a.Salary ascending 
      select new Employee() { 
          ID=a.Id, 
          Fname=a.FName, 
          Lname=a.Lname, 
          Gender=a.Gender, 
          Salary=a.Salary, 
          DepartmentId=a.DeparmentId 
      }; 
      l= qry.ToList(); 
      var e1 = from emp in context.tbl_employees 
       where emp.Gender == "Male" 
       orderby emp.Salary descending 
       select emp; 
      GridView1.DataSource = l; 
      GridView1.DataBind(); 
     } 
    } 
    public class Employee 
    { 
     public Int64 ID { get; set; } 
     public String Fname { get; set; } 
     public String Lname { get; set; } 
     public String Gender { get; set; } 
     public decimal? Salary { get; set; } 
     public int? DepartmentId { get; set; } 
    } 
} 

Answer 5

using System.Collections.Generic; 
using System.Linq; 

IList<Person> people = new List<Person>(); 
IList<string> firstNames = people.Select(person => person.FirstName).ToList();