vb.net MouseWheel，确定上下滚动事件
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MouseWheel, determining up and down scrolling events
提问by Craig
Is there any way to determine if the mouse scrolls up or down using the Mousewheel handler on a sub? eg
有什么方法可以使用子上的鼠标滚轮处理程序来确定鼠标是向上还是向下滚动？例如
Private Sub PictureBox1_MouseWheel(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseWheel
if mousewheel.scrollup then
UserZoom = UserZoom + 0.05
Me.Refresh()
end if
End Sub
I want to be able to adjust the value of userzoom up or down according to if the mouse is wheeled up or down. Any help would be appreciated guys
我希望能够根据鼠标向上或向下滚动来向上或向下调整 userzoom 的值。任何帮助将不胜感激伙计们
回答by M.A. Hanin
Check the Delta property of the MouseEventArgs:
检查 MouseEventArgs 的 Delta 属性：
Sample code:
示例代码：
Private Sub Form1_MouseWheel(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseWheel
If e.Delta > 0 Then
Trace.WriteLine("Scrolled up!")
Else
Trace.WriteLine("Scrolled down!")
End If
End Sub
回答by Craig
Figured it out.
弄清楚了。
e.deltapasses either negative or positive values according to if the mouse is scrolled up or down!
e.delta根据鼠标向上或向下滚动传递负值或正值！
