VB.Net暫停和恢復對下一個

Question

我有以下代碼（VB.Net）正在做我想要的東西（即暫停在特定的時間間隔/位置的代碼和恢復時，單擊Messagebox按鈕）... .... 唯一的問題是，我用了一個messagebox;有沒有一種方法可以使用按鈕來完成相同的工作;沒有計時器，沒有消息框？

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click 
    Dim Index As Integer 
    For KKK = 1 To 50 
     Index = KKK/5 
     If Index = KKK/5 Then 
      MessageBox.Show("Paused at: " & KKK & " : Click OK to Resume") 
     End If 
    Next 
End Sub 

在此先感謝您的意見和幫助。

Answer 1

如果升級到VS2013共同體（這是免費的），那麼你可以使用異步/等待組合是這樣的：

Public Class Form1 

    Private MRE As New Threading.ManualResetEvent(False) 

    Private Async Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click 
     Button1.Enabled = False 
     Button2.Enabled = False 

     For KKK = 1 To 50 
      If KKK Mod 5 = 0 Then 
       Label1.Text = KKK 
       MRE.Reset() 
       Button2.Enabled = True 
       Await WaitForButton() 
      End If 
     Next 

     Button1.Enabled = True 
    End Sub 

    Private Function WaitForButton() As Task 
     Return Task.Run(Sub() 
          MRE.WaitOne() 
         End Sub) 
    End Function 

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click 
     Button2.Enabled = False 
     MRE.Set() 
    End Sub 

End Class 

Answer 2

您可以通過將循環放入單獨的線程，休眠以及按下按鈕中斷來完成此操作。在這個例子中，button1啓動循環，而button2在thread.sleep處中斷它。

Dim newThread As New Thread(AddressOf loopSub) 
Delegate Sub textAddCallback(ByVal s As string) 

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click 
newThread.Start() 
End Sub 

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click 
newThread.Interrupt() 
End Sub 

Sub loopSub() 
    Dim Index As Integer 
    Dim textDelegate As New textAddCallback(AddressOf textAdd) 

    Try 
     For KKK As Integer = 1 To 50 
      Index = KKK/5 
      If Index = KKK/5 Then 
       Thread.Sleep(36000) ' sleep the max amount of milliseconds 
      End If 
     Next 
    Catch ex As ThreadInterruptedException 
     Me.Invoke(textDelegate, "string to add") 
    End Try 

End Sub 

Sub textAdd(ByVal s As String) 
rtext1.text &= s 
End Sub 

Answer 3

2個按鈕和一個標籤是必需的。試試這個：

Dim Pause As Boolean  

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button2.Click 
    Dim Index As Integer 
    Pause = False 
    Button2.Text = "Ok" 
    Button2.Enabled = False 
    For KKK = 1 To 50 
     System.Threading.Thread.Sleep(250) 'Just for testing purposes, do not use this instruction. 
     Index = KKK/5 
     If Index = KKK/5 Then 
      Label1.Text = "Paused at: " & KKK & " : Click OK to Resume" 
      Pause = True 
      Button2.Enabled = True 
      Button2.Focus() 
      While Pause 
       Application.DoEvents() 
      End While 
      Label1.Text = "" 
      Button2.Enabled = False 
     End If 
    Next 
End Sub 

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click 
    Pause = False 
End Sub