Scrollbar flicker when calling EnableScrollBar

Question

I'm using p/invoke to call EnableScrollBar from user32.dll (MSDN reference). I noticed that when the scrollbar is enabled, it seems to draw as though no theme is applied and then re-drawn with the theme applied. I've only tested with Windows 7 so far. Is there any way to stop this from happening?

EDIT: Here's some code to show what happens (dump into a form with scrollbars):

private class Native
{
    [DllImport("user32.dll")]
    public static extern bool EnableScrollBar(IntPtr hWnd, uint wSBflags, uint wArrows);

    public static class SBArrows
    {
        public const uint ESB_ENABLE_BOTH = 0;
        public const uint ESB_DISABLE_BOTH = 3;
        public const uint ESB_DISABLE_LEFT = 1;
        public const uint ESB_DISABLE_RIGHT = 2;
        public const uint ESB_DISABLE_UP = 1;
        public const uint ESB_DISABLE_DOWN = 2;
        public const uint ESB_DISABLE_LTUP = 1;
        public const uint ESB_DISABLE_RTDN = 2;
    }

    public static class SBFlags
    {
        public const uint SB_HORZ = 0;
        public const uint SB_VERT = 1;
        public const uint SB_CTL = 2;
        public const uint SB_BOTH = 3;
    }
}


private bool Switch = false;

protected override void OnMouseDown(MouseEventArgs e)
{
    Native.EnableScrollBar(this.Handle, Native.SBFlags.SB_HORZ, this.Switch ? Native.SBArrows.ESB_DISABLE_BOTH : Native.SBArrows.ESB_ENABLE_BOTH);
    this.Switch = !this.Switch;
}

Final Solution

Native.SendMessage(this.Handle, Native.WindowMessages.WM_SETREDRAW, new IntPtr(0), IntPtr.Zero);
Native.EnableScrollBar(this.Handle, Native.SBFlags.SB_HORZ, Native.SBArrows.ESB_ENABLE_BOTH);
Native.SendMessage(this.Handle, Native.WindowMessages.WM_SETREDRAW, new IntPtr(1), IntPtr.Zero);

Answer 1

I don't like this solution much. It does however work:

    protected override void OnMouseDown(MouseEventArgs e) {
        Native.LockWindowUpdate(this.Handle);
        Native.EnableScrollBar(this.Handle, Native.SBFlags.SB_HORZ, this.Switch ? Native.SBArrows.ESB_DISABLE_BOTH : Native.SBArrows.ESB_ENABLE_BOTH);
        //this.Invalidate();
        Native.LockWindowUpdate(IntPtr.Zero);
        this.Switch = !this.Switch;
    }