如何暂停一个循环内的动画无延迟

Question

我有这段代码的问题：

---

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 

---

的问题是，当我按我的表单上的按钮，停止代码（使用StopProgram = False），它会一直持续到Count = v我希望能够在循环内停止它，我试图在这里做到这一点，但它创建了一个不幸的循环，它毁了程序。

Answer 1

更好的是，使用定时器定时打勾。

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作为新System.Timers.Timer

子t_Elapsed把手....

“你的代码在这里。递增/递减状态变量 结束子

只需要在停止动画时禁用定时器。

Answer 2

这是错误方法您的问题，但改变：

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个外环。
你永远不会到达Do Until Count = v部分，除非StopProgram是真的。 你会留在内部Do While StopProgram = False循环。当您退出环路中间，所以如果你需要保留数量的值时StopProgram设置为true，你应该删除你可以删除 内Do While StopProgram = False loop，改变 Do Until Count = v到Do Until Count = v或者StopProgram = true

顺便说一句你设置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

这应该只是罚款。不需要所有这些循环。

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