使用lambda表達式在Linq的列表中創建一個新的通用列表？

Question

好吧，我有一個POCO類可能包含另一個POCO類作爲數組。在某些情況下，當我獲得數據時，我想要創建列表的列表，但不是降級，但都處於同一級別。我想我錯過了很簡單的東西，所以我想我會在這裏問。我一直嘗試使用不同的語法來處理Lambdas，但數據在那裏，我可以永遠不會讓它出現在頂部附近。如果可能的話，我希望解決方案能夠在lambda表達式中，而不是做舊式的foreach。我不確定你是否可以內聯這樣做，或者你必須首先聲明一個集合，然後添加到它。當我在：

class Program 
    { 
     public class lowerlevel 
     { 
      public string ChildName; 
     } 

     public class upperlevel 
     { 
      public string ItemName; 

      public lowerlevel[] ChildNames; 
     } 

     static void Main(string[] args) 
     { 
      // Create a list of a POCO object that has lists in it as well. 
      List<upperlevel> items = new List<upperlevel> 
       { 
        // declaration of top level item 
        new upperlevel 
        { 
         ItemName = "FirstItem", 
         // declaration of children 
         ChildNames = new lowerlevel[] 
          {new lowerlevel {ChildName = "Part1"}, new lowerlevel {ChildName = "Part2"}}, 

        }, 
        // declaration of top level item 
        new upperlevel 
        { 
         ItemName = "SecondItem", 
         // declaration of children 
         ChildNames = new lowerlevel[] { new lowerlevel { ChildName = "Part3" } } 
        } 
       }; 


      var stuff = items.Select(l1 => l1.ChildNames.ToList().Select(l2 => 
       new lowerlevel 
       { 
        ChildName = l2.ChildName 
       })) 
       .ToList(); 

      // Arghh! I just want to make a new list with lambdas that is NOT nested a level down! This is NOT what I want but it is valid. 
      stuff.ForEach(n => n.ToList().ForEach(n2 => n2.ChildName)); 

      // I want this but it does not work as I am not doing the expression right 
      // stuff.Foreach(n => n.ChildName); 

     } 

    } 

Answer 1

嘗試使用SelectMany()不是.Select()

var stuff = items.SelectMany...