vb.net - MouseWheel，确定上下滚动事件

Question

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

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

Answer 1

检查 MouseEventArgs 的 Delta 属性:

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