Объединить группы LINQ?

Question

Предположим, у меня есть эти объекты домена:

DataPoint 
    ========= 
    public int Id {get;set;} 
    public int TypeId {get;set;} 
    public string Name {get;set;} 

    Connector 
    ========= 
    public DataPoint DataPoint1 {get;set;} 
    public int DataPoint1Id {get;set;} 
    public DataPoint DataPoint2 {get;set;} 
    public int DataPoint2Id {get;set;} 
    public string Name {get;set;} 
    public int TypeId {get;set;} 

У меня есть List<Connector>:

List<Connector> _Connectors = new List<Connector>() 
    { 
    new Connector(){Name = "a", DataPoint1Id = 1, DataPoint2Id = 2},... 
    new Connector(){Name = "b", DataPoint1Id = 1, DataPoint2Id = 2},... 
    new Connector(){Name = "c", DataPoint1Id = 1, DataPoint2Id = 2},... 
    new Connector(){Name = "d", DataPoint1Id = 2, DataPoint2Id = 1},... 
    new Connector(){Name = "e", DataPoint1Id = 2, DataPoint2Id = 1}... 
    } 

я делаю группировка с помощью LINQ следующим образом:

var groups = (from C in _Connectors 
        group C by new { C.DataPoint1Id, C.DataPoint2Id } 
        into cGroup            
        select new {cGroup.Key.DataPoint1Id, cGroup.Key.DataPoint2Id,  
    cGroup.ToList(), cGroup.Count()}); 

вар группы держит:

DataPoint1Id = 1, DataPoint2Id = 2, list of connectors -"a","b","c", count = 3 
    DataPoint1Id = 2, DataPoint2Id = 1, list of connectors - "d","e", count = 2 

Я хотел бы объединить эти 2 объекта в 1:

DataPoint1Id = 1, DataPoint2Id = 2, list of connectors - "a","b","c","d","e", count = 5 

Как я могу добиться этого?

Answer 1

Как насчет

var groups = 
    from C in _Connectors 
    group C by new 
     { 
      Min = (int)Math.Min(C.DataPoint1Id, C.DataPoint2Id), 
      Max = (int)Math.Max(C.DataPoint1Id, C.DataPoint2Id) 
     } 
    into cGroup 
    select new 
     { 
      DataPoint1Id = cGroup.Key.Min, 
      DataPoint2Id = cGroup.Key.Max, 
      Connectors = cGroup.ToList(), 
      Count = cGroup.Count() 
     };