Bug Exposed: Invisible CrystalTrackBar

A little over a week ago, a user named MG reported a problem that I couldn't duplicate until now. When he ran the demo program CrystalTrackBarDemo.exe, all the CrystalTrackBar objects were invisible. No trackbar, no ticks, no thumb, only the gradient background remained on the non-transparent objects. After a second user reported this bug on the CodeProject article, I suddenly remembered about my usage of TrackBarRenderer.IsSupported in CrystalTrackBar OnPaint:

protected override void OnPaint(PaintEventArgs e)
{
    if (!TrackBarRenderer.IsSupported)
    {
        this.Parent.Text = 
            "CrystalTrackBar Disabled";
        return;
    }

    DrawTrackBar(e.Graphics);
    DrawTicks(e.Graphics);
    DrawThumb(e.Graphics);
}

On the MSDN Forum, Mick Doherty pointed out that TrackBarRenderer.IsSupported == VisualStylesRenderer.IsSupported. According to the documentation, one of the things that can make the VisualStylesRenderer is the VisualStyleInformation.IsEnabledByUser property. Users can enable visual styles in the Appearance tab of the Display option in Control Panel.

I was able to reenact the bug by setting my Appearance setting for Windows and Buttons to Windows Classic Style (on XP: Control Panel->Display->Appearance tab). As some people are addicted to the old Windows NT look and feel, it makes sense this how they ran into the bug. When I ran my application again, TrackBarRenderer.IsSupported returned false and all I got was the rectangles, no trackbar or ticks.

I'll need to draw the TrackBar and Ticks myself if TrackBarRenderer isn't supported. I'm already drawing the Thumb, so this should be an easy bug to fix. I hope to have it posted in a few days.