Question

I have a third party ActiveX control that I am embedding in a form. The control’s class implements IDisposable. My question is should I manually call the control’s dispose method either in the form closing event or go into the designer and edit the form dispose method to call the control’s dispose.

I understand that a form calls the dispose methods of all the controls it owns, however are there any exceptions since this is a COM control. Thanks.

PS: I am using Visual Studio 2008, .Net 3.5, Project Type: Windows Forms Application

Answer 1

No, there is nothing special you have to do.

Because the Control class (from which other container controls such as Form inherit from) implements the IDisposable interface, it should (if it follows the standard IDisposable implementation guidelines) dispose of any references that it holds that implement the IDisposable interface.

That said, your control, assuming that it is in the controls collection exposed by the Controls property, will have it’s IDisposable.Dispose method called when the window containing it is closed (as closing the window causes the window’s Dispose method to be called).