C#, Form, Control ... Showing a non-blocking message to user without any button

Question

Hi !

I try to show a MESSAGE to the user while an operation is executed. The MESSAGE won't show any button ... just a MESSAGE (text) and maybe a background image.

The problem is the following: MessageBox does not seem to be the good control (because of button and it blocks the running process), Form.ShowDialog() also blocks the running process .... I don't know what to do.

I want to show the message, run my process, and dispose the message when the process is done.

How to achieve this in C# ?