C# UserControl.VerticalScroll.Value not being set

Question

I\'ve got a chunk of C# code that is supposed to set VerticalScroll.Value within a class that inherits from UserControl. It gets called when any child object of the class c

Answer 1

FlowLayoutPanel seems to be a different beast. The scroll bar does move down, but the value of flowlayoutpanel.VerticalScroll.Value remains at 0. I tried all above techniques plus some DoEvents() and Thread.Sleep(), even a timer which fully yielded before doing its next iteration. It all failed. I eventually discovered that DisplayRectangle.Y was instantly expressing the scroll change...

private void PrintButton_Click(object sender, EventArgs e)
{
    FlowLayoutPanel flp = TheBuildFlowLayoutPanel;
    List printPics = new List();
    int printLastY = 100;
    flp.VerticalScroll.Value = 0;
    while (flp.DisplayRectangle.Y < printLastY) // DisplayRect.Y becomes successively more negative
    {
        Bitmap bmp = new Bitmap(flp.Width, flp.Bounds.Height);
        printPics.Add(bmp);
        flp.DrawToBitmap(bmp, flp.ClientRectangle);
        printLastY = flp.DisplayRectangle.Y;
        flp.VerticalScroll.Value = Math.Min(flp.VerticalScroll.Maximum, flp.VerticalScroll.Value + flp.Height);
    }

    flp.VerticalScroll.Value = 0;
    for (int i = 0; i < printPics.Count; i++)
    {
        printPics[i].Save("C:\\Temp" + i.ToString() + ".bmp");
    }
}