自定义ListBox无法使用DrawMode.OwnerDrawVariable正确滚动

Question

我制作了一个自定义ListBox，因此我可以改变它的绘制方式。我已将DrawMode设置为OwnerDrawVariable，并已处理DrawItem和MeasureItem事件。

当我向下滚动列表框时，它似乎向错误的方向滚动。它最终在正确的位置，但动画不正确。

问题似乎与OwnerDrawVariable有关，因为它在OwnerDrawFixed上滚动得很好。但是我必须使用OwnerDrawVariable。有什么想法吗？

Private Sub wrapListBox_DrawItem(ByVal sender As Object, ByVal e As System.Windows.Forms.DrawItemEventArgs) Handles Me.DrawItem
    e.DrawBackground()
    Dim myBrush As Brush = Brushes.Black
    If e.Index Mod 2 = 0 Then
        e.Graphics.FillRectangle(Brushes.LightGray, e.Bounds)
    Else
        e.Graphics.FillRectangle(Brushes.White, e.Bounds)
    End If
    If (e.State And DrawItemState.Selected) Then
        e.Graphics.FillRectangle(Brushes.DarkBlue, e.Bounds)
        myBrush = Brushes.White
    End Ifsettings. 

    e.Graphics.DrawString(Me.Items(e.Index), Me.Font, myBrush, New RectangleF(e.Bounds.X, e.Bounds.Y, e.Bounds.Width, e.Bounds.Height))
    e.DrawFocusRectangle()
End Sub

Private Sub wrapListBox_MeasureItem(ByVal sender As Object, ByVal e As System.Windows.Forms.MeasureItemEventArgs) Handles Me.MeasureItem
    Dim g As Graphics = e.Graphics
    Dim size As SizeF = g.MeasureString(Me.Items.Item(e.Index).ToString, Me.Font, Me.Width - 5 - SystemInformation.VerticalScrollBarWidth)
    e.ItemHeight = CInt(size.Height) + 5
    e.ItemWidth = CInt(size.Width) + 5
End Sub