How to make the form completely transparent

Question

I already made the background transparent but there is still some part left from the group box. How do I make those transparent also?

The blank line are what I want it to be transparent. It should give you the picture of what I want. Thanks.

And don't even ask what are the password for, all of them are just dummies :)

If you want to see and edit the code, here

Answer 1

That's just how the GroupBox control works. The Background property of that control includes the area that your screenshot points to. If you wanted to do a workaround for it, you should set the GroupBox background to be transparent as well, and draw a white box behind it, encompassing only the area you want to be white.

Answer 2

Form.Opacity对您不起作用？

Answer 3

What is the GroupBox's parent container? Is it a Form or a Panel? Is that element also set to transparent? As a test I made a GroupBox and placed it on top of (inside) a Panel. I changed the background color of the Panel to red and the background color of the GroupBox to transparent and those ares of the GroupBox are properly transparent. My suggestion is to look at the parent container.

Also the GroupBox label may become hard to read in some cases, once the top strip is transparent.