How to programmatically add panels?

You can also programmatically add event hooks. You can write your event handler, so in this case the shell is

private void panel_Paint(object sender, PaintEventArgs e)
{

}

Then, whenever you add a new panel to the form, you add an event handler to that panel like so:

Panel newPanel = new Panel();

//set panel position and other properties

//Add the event handler
newPanel.Paint += new PaintEventHandler(this.panel_Paint);

//Add it to the form
this.Controls.Add(newPanel);

Then, whenever your new panel is painted, it will go to your handler.
There's an example here[^]