在LINQ條件查詢中使用「或」

Question

我有一個帶CheckedListBox的表單，用戶可以在其中選擇多個選項（它正在篩選目錄文件列表 - 篩選的文件出現在第二個列表框中）。

如果我有選擇的一組號碼，我可以在這樣的查詢使用「或」：

Dim query = From f As System.IO.FileInfo In StartList 
    Where f.Name.Contains("Romania") 
Where f.Channel = "Channel1" Or f.Channel = "Channel2" 

但隨着人可以點擊任意數量的選項（或沒有）我不能這樣做這個。 我已經嘗試了幾件事情，包括嘗試創建多個子查詢，然後對它們執行聯合，但是我無法使其工作。

這是到目前爲止我的代碼：

Dim Channels = ChannelListBox.CheckedItems 

    Dim query = From f As System.IO.FileInfo In StartList 
    Where f.Name.Contains("Romania") 

    If Channels.Count > 0 Then 

     Dim CurrentName As String = Channels(0).ToString 

     Dim Subquery = From g As System.IO.FileInfo In query 
       Where (g.Name.Contains(CurrentName)) 

     For i = 1 To Channels.Count - 1 

      CurrentName = Channels(i).ToString 
      Dim Subquery2 = From h As System.IO.FileInfo In query 
           Where (h.Name.Contains(CurrentName)) 

      Subquery = Subquery.Union(Subquery2) 

     Next i 

     FileListBox.DataSource = Subquery.ToList 

    Else 

     FileListBox.DataSource = query.ToList 

    End If 

感謝您的幫助， 安德魯

Answer 1

Dim Channels = ChannelListBox.CheckedItems 
Dim ChannelNames = From c.ToString In Channels 
Dim query = From f As System.IO.FileInfo In StartList 
    Where f.Name.Contains("Romania") And ChannelNames.Any(Function(n) f.Name.Contains(n)) 

我沒有經驗VB.NET，更不用說使用LINQ，所以我希望我的語法是正確的。這裏是我會寫在C＃中：

var channels = ChannelListBox.CheckedItems; 
var channelNames = channels.Select(c => c.ToString()); 
var query = from f in StartList.Cast<System.IO.FileInfo>() 
    where f.Name.Contains("Romania") && channelNames.Any(n => f.Name.Contains(n)) 
    select f;