從另一個列表中刪除項目的擴展方法

Question

我試圖根據謂詞Func過濾列表。我使用Func過濾完整列表並返回操作的結果。然後我需要確定哪些MachineAction出現在完整列表中，但不是過濾列表。

static void Main(string[] args) 
{ 
    var allActions = new List<MachineAction> 
        { 
         new MachineAction 
          { Name = "A", Status = MachineActionStatus.Cancelled }, 
         new MachineAction 
          { Name = "B", Status = MachineActionStatus.Error }, 
         new MachineAction 
          { Name = "C", Status = MachineActionStatus.Waiting } 
         }; 

    var filteredActions = allActions.Where(FilterNotCompleted); 
} 

private readonly static Func<MachineAction, bool> FilterNotCompleted = action => 
             (action.Status == MachineActionStatus.Waiting || 
              action.Status == MachineActionStatus.Started); 

public class MachineAction 
{ 
    public MachineActionStatus Status { get; internal set; } 
    public string Name { get; internal set; } 
} 

internal enum MachineActionStatus 
{ 
    Waiting, 
    Started, 
    Success, 
    Error, 
    Cancelled 
} ; 

是否有將完整名單與過濾列表，並返回那些未在這兩個擴展方法？

感謝

Answer 1

看看在Except擴展

Answer 2

allActions.Where(item => !filteredActions.Contains(item)) 

但也許更好是做

var filteredActions = allActions.Where(item => !FilterNotCompleted(item)); 

（注意！bevore func命令。）

Answer 3

allActions.Except(filteredActions)