完成一個接一個循環

Question

真的很簡單。我想只有一次關於電子第一已經停止了第二循環開始...

  Dim i As Integer 
     For Each c As Control In AllSongsPanel.Controls 
      If c.BackColor = Color.FromArgb(30, 30, 30) Then 
       My.Computer.FileSystem.DeleteFile(c.Tag) 
       i = c.Name 
       c.Dispose() 
       deletedCount = deletedCount + 1 
      End If 
     Next 
     itemCount = 0 
     For Each c As Control In AllSongsPanel.Controls 
      If c.Width = AllSongsPanel.Width - 23 Then 
       itemCount = itemCount + 1 
       c.Name = itemCount 
      End If 
     Next 

我真的沒有在這許多的想法，我無法找到谷歌在此的任何問題。我的想法可能會比需要的更廣泛，所以我想先檢查一下是否有更簡單的解決方案。 我看過msdn上的循環，什麼都沒有，但沒有找到任何東西。

Answer 1

更改刪除該控件的方式。

Dim mDeleted as new List(of Control) 
Dim i As Integer 

For Each c As Control In AllSongsPanel.Controls 
    If c.BackColor = Color.FromArgb(30, 30, 30) Then 
     My.Computer.FileSystem.DeleteFile(c.Tag) 
     i = c.Name 

     mDeleted.Add(c) 

     ' no longer needed (?) 
     'deletedCount = deletedCount + 1 
    End If 
Next 

For each C as control in mDeleted 
    ' i think this is the right syntax: 
    AllSongsPanel.Controls.Remove(c) 
Next 

' add the second loop...not sure what it is doing 

deletedCount相同mDeleted.Count。

i As INTEGER = c.NAME也沒有多大意義。

Answer 2

由於您沒有關閉任何線程，因此此代碼已經是同步的。你應該已經得到了這個行爲。

Answer 3

當你在這個列表中的for..each循環中時，你不能從列表中刪除一個項目。我首先要記住所有應刪除的項目，並在之後有效刪除它們。事情是這樣的：

Dim i as integer 
Dim deleteControls As New List(Of Control) 
For Each c As Control In AllSongsPanel.Controls 
    If c.BackColor = Color.FromArgb(30, 30, 30) Then 
     deleteControls.Add(c) 
    End If 
Next 

For Each c As Control In deleteControls 
    My.Computer.FileSystem.DeleteFile(c.Tag) 
    i = c.Name 
    AllSongsPanel.Controls.Remove(c) 
    deletedCount = deletedCount + 1 
Next 
...