How can I get rounded corners in a GroupBox in my form? Is there any option in the property tab?
When visual styles are enabled for your application and the FlatStyle property is set to "System", the group boxes look like they have slightly rounded corners, but it's probably no more than 3 to 5 degrees. So I suppose this is not what you're looking for.
Unfortunately, there's no built-in way to customize its degree of roundedness. The only real solution is to use a custom control. You can either inherit off of the existing GroupBox control and override its Paint event to draw the borders yourself, or you can use one of these existing controls: