如何暫停一個循環內的動畫無延遲

Question

我有這段代碼的問題：

---

Do While StopProgram = False 
     Do Until Count = v 
      Application.DoEvents() 
      Do While StopProgram = False 
       If DirectionNegative = False Then 
        Me.Refresh() 
        Count += 1 
        Angle += 1 
        RadianAngle = Angle * PlaceHolder 
        If Angle >= 51 Then 
         Angle = 49 
         DirectionNegative = True 
        End If 
       ElseIf DirectionNegative = True Then 
        Me.Refresh() 
        Count += 1 
        Angle -= 1 
        RadianAngle = Angle * PlaceHolder 
        If Angle <= -51 Then 
         Angle = -49 
         DirectionNegative = False 
        End If 
       End If 
      Loop 
     Loop 
      Count = 0 
     Loop 

---

的問題是，當我按我的表單上的按鈕，停止代碼（使用StopProgram = False），它會一直持續到Count = v我希望能夠在循環內停止它，我試圖在這裏做到這一點，但它創建了一個不幸的循環，它毀了程序。

Answer 1

更好的是，使用定時器定時打勾。

http://msdn.microsoft.com/en-us/library/system.timers.timer(v=vs.110).aspx?cs-save-lang=1&cs-lang=vb#code-snippet-2

昏暗WITHEVENTS T作爲新System.Timers.Timer

子t_Elapsed把手....

「你的代碼在這裏。遞增/遞減狀態變量 結束子

只需要在停止動畫時禁用定時器。

Answer 2

這是錯誤方法您的問題，但改變：

Do While StopProgram = False 
    Do Until Count = v 
     Application.DoEvents() 
     Do While StopProgram = False 

要：

Do While StopProgram = False 
    Do Until Count = v 
     Do While StopProgram = False 
      Application.DoEvents() 

Answer 3

你可以只取出2個外環。
你永遠不會到達Do Until Count = v部分，除非StopProgram是真的。 你會留在內部Do While StopProgram = False循環。當您退出環路中間，所以如果你需要保留數量的值時StopProgram設置爲true，你應該刪除你可以刪除 內Do While StopProgram = False loop，改變 Do Until Count = v到Do Until Count = v或者StopProgram = true

順便說一句你設置Count = 0外 Do While StopProgram = False loop和Count = 0

Do Until Count = v Or StopProgram = True 
    Application.DoEvents() 
    If DirectionNegative = False Then 
     Me.Refresh() 
     Count += 1 
     Angle += 1 
     RadianAngle = Angle * PlaceHolder 
     If Angle >= 51 Then 
      Angle = 49 
      DirectionNegative = True 
     End If 
    ElseIf DirectionNegative = True Then 
     Me.Refresh() 
     Count += 1 
     Angle -= 1 
     RadianAngle = Angle * PlaceHolder 
     If Angle <= -51 Then 
      Angle = -49 
      DirectionNegative = False 
     End If 
    End If 
Loop 

Answer 4

這應該只是罰款。不需要所有這些循環。

Public Sub Refresh() 
    ' ... 
End Sub 

Public Property Get StopProgram() As Boolean 
    StopProgram = ' ... 
End Property 

Public Property Get Angle as Single 
'... 
Public Property Let Angle 
'... 

Public Property Get RadianAngle as Single 
    RadianAngle = Angle * PlaceHolder 
End Property 

Public Sub T() 

    Dim Step As Single   
    Step = 1! 
    Do 
     DoEvents 
     Me.Refresh 
     If StopProgram Then Exit Do 
     If Angle <= 0 Or Angle >= 50 Then 
      Step = -Step 
     End If 
     Count = Count + 1 
     Angle = Angle + Step 
    Loop 

End Sub