c# - ToolstripButton remain focused in an MDI Form -

i have mdi form mdi container, toolstrip bar buttons , child form. on child form there third's part component draw cad application.

if click on toolstripbutton start draw something, button remains in state pressed , execute operation must click somewhere on screen.

if use menustrip don't have trouble.

why toolstrip have behavior?

if focus stays in button, can focus cad part manually use it:

public void mybutton_click(object sender, eventargs e) {    // other code...    cadcomponent.focus(); } 

not sure why behaves that, though.