C＃合并两个对象列表

Question

我有两个列表，我想合并成一个列表。 Active Directory中的计算机列表以及SCCM中的计算机列表。

利斯塔包含：

public string ComputerName { get; set; } 
    public string OperatingSystem { get; set; } 
    public DateTime? LastLogon { get; set; } 

数组listB包含：

public string ComputerName { get; set; } 
    public DateTime[] AgentTime { get; set; } 
    public string LastLogonUserName { get; set; } 

我想通过计算机名进行合并，但如果我这样做与加盟使用（例如）：

var query = from ObjectA in ListA 
      join ObjectB in ListB on ObjectA.ComputerName equals ObjectB.ComputerName 
      select new { computername = ObjectA.ComputerName, lastlogonusername = ObjectB.LastLogonUserName }; 

它只显示两个列表的结果。我要让计算机列表中AD与那些还含有SCCM

ListC附加信息：

public string ComputerName { get; set; } 
    public string OperatingSystem { get; set; } 
    public DateTime? LastLogon { get; set; } 
    public DateTime[] AgentTime { get; set; } 
    public string LastLogonUserName { get; set; } 

什么是这样做的最佳方式？

Answer 1

你需要一个外部联接：

var query = 
     from ObjectA in ListA 
     join ObjectB in ListB on ObjectA.ComputerName equals ObjectB.ComputerName into tmp 
     from ObjectB in tmp.DefaultIfEmpty() 
     select new { computername = ObjectA.ComputerName, lastlogonusername = ObjectB?.LastLogonUserName }; 

注上ObjectB使用?.：这是因为如果在ListB没有匹配的项目，ObjectB将是无效的。

（如果你不使用C＃6，你可以做ObjectB != null ? ObjectB.LastLogonUserName : null代替）

Answer 2

为什么不把所有内容添加到一个列表中，然后只需通过ComputerName获取一个不同的列表？

// Convert all B objects to A objects 
var objectBsAsAs = ListB.Select(x => new ObjectA() { ComputerName = x.ComputerName, LastLogonUserName = x.LastLogonUserName }); 
// Add all B objects to the list of A objects 
var allComputers = ListA.AddRange(objectBsAsAs); 
// Get a distinct list based on ComputerName 
var distinct = ListA.Distint(new ComputerNameComparer()); 

private class ComputerNameComparer : IEqualityComparer<ObjectA> 
{ 
    public bool Equals(ObjectA a, ObjectA b) 
    { 
     return a.ComputerName == b.ComputerName; 
    } 
} 

Answer 3

像这样的东西可能会帮助 -

 var l1 = new List<A> 
     { 
      new A 
      { 
       ComputerName = Dns.GetHostName(), 
       LastLogon = DateTime.Now, 
       OperatingSystem = "Windows" 
      } 
     }; 

     var l2 = new List<B> 
     { 
      new B 
      { 
       AgentTime = new DateTime[]{DateTime.Now}, 
       ComputerName = Dns.GetHostName(), 
       LastLogonUserName = "me" 
      } 
     }; 


     var o = from r in l2 
       join q in l1 on r.ComputerName equals q.ComputerName 
       into grp 
       from p in grp.DefaultIfEmpty() 
       select new C 
       { 
        AgentTime = r.AgentTime, 
        ComputerName = p.ComputerName, 
        LastLogon = p.LastLogon, 
        OperatingSystem = p.OperatingSystem, 
        LastLogonUserName = r.LastLogonUserName 
       };