I’m following this tutorial

I have a program which I am updating, and what I am going to do is that when I click outside of a GridView type object, it will send an instruction only once to other objects (Textbox, Labels, etc). I did some tests on the MouseLeave() event and it does in a certain way what I need, but it does it all the time while I am outside the GridView and that is my detail that when I am outside the GridView, the event repeats every so often without What can stop it, any ideas or other events I can use?