如何通过主键使用linq将三个对象列表组合起来

Question

我试图组合3个对象列表。我有一个人名单，地址列表和地址关联列表。 我想将这些列表合并到由person.id排序的新列表中，将其用作listview的数据源，然后能够访问aspx页面中的属性。

这可能吗？

Answer 1

大约

using System.Linq; 

class Person 
{ 
    public int Id; 
    public string Name; 
} 

class Address 
{ 
    public int Id; 
    public string Street; 
} 

class PersonAddress 
{ 
    public int PersonId, AddressId; 
} 

public class Program 
{ 
    public static void Main(string[] args) 
    { 
     var personList = new [] 
     { 
      new Person { Id = 1, Name = "Pete" }, 
      new Person { Id = 2, Name = "Mary" }, 
      new Person { Id = 3, Name = "Joe" } 
     }; 

     var addressList = new [] 
     { 
      new Address { Id = 100, Street = "Home Lane" }, 
      new Address { Id = 101, Street = "Church Way" }, 
      new Address { Id = 102, Street = "Sandy Blvd" } 
     }; 

     var relations = new [] 
     { 
      new PersonAddress { PersonId = 1, AddressId = 101 }, 
      new PersonAddress { PersonId = 3, AddressId = 101 }, 

      new PersonAddress { PersonId = 2, AddressId = 102 }, 
      new PersonAddress { PersonId = 2, AddressId = 100 } 
     }; 

     var joined = 
        from par in relations 
        join p in personList 
         on par.PersonId equals p.Id 
        join a in addressList 
         on par.AddressId equals a.Id 
        select new { Person = p, Address = a }; 

     foreach (var record in joined) 
      System.Console.WriteLine("{0} lives on {1}", 
            record.Person.Name, 
            record.Address.Street); 
    } 
} 

输出：

Pete lives on Church Way 
Mary lives on Sandy Blvd 
Mary lives on Home Lane 
Joe lives on Church Way