Gradient Panel shows red cross when minimized and then restored

Question

I have no idea why this is happening, but I created the below code which is a gradient panel, the panel is then docked to the left of the screen.

When the form is re

Answer 1

I'm doing something similar, but even cleaning up the LinearGradientBrush didn't fix it for me. Looking at the console output, I noticed "A first chance exception of type System.ArgumentException occurred in System.Drawing.dll." I believe this is because the ClientRectangle is 0,0 when the component is minimized. Adding this code seemed to fix it for me:

  protected override void OnPaintBackground(PaintEventArgs e)
  {
     base.OnPaintBackground(e);
     if (this.gradientBrush != null)
        this.gradientBrush.Dispose();
     if (this.ClientRectangle.Width > 0 && this.ClientRectangle.Height > 0)
     {
        this.gradientBrush = new LinearGradientBrush(this.ClientRectangle,
           FROM_GRADIENT_COLOR, TO_GRADIENT_COLOR, LinearGradientMode.Horizontal);

        e.Graphics.FillRectangle(this.gradientBrush, this.ClientRectangle);
     }
  }