LINQ如何GROUPBY正確

Question

我有以下類：

class AssembledDTO 
{ 
    int pid, 
    int blockId, 
    List<string> references 
} 

我想組通過一切方式如下：

AssembledParts.GroupBy(entry => new 
         { 
          entry.PID, 
          entry.BlockId 
         }). 
         Select((key , val)=> new AssembledDTO 
          { 
           BlockId = key.Key.BlockId, 
           PID = key.Key.PID, 
           References = val. 
          }) 

在References我想加在一起都references名單我分組的每個羣組。

我該怎麼做？我在這裏想念什麼？

Answer 1

SelectMany應該訣竅來平坦化結果。

AssembledParts.GroupBy(entry => new 
        { 
         entry.PID, 
         entry.BlockId 
        }). 
        Select(key => new AssembledDTO 
         { 
          BlockId = key.Key.BlockId, 
          PID = key.Key.PID, 
          References = key.SelectMany(v => v.references).ToList(); 
         })