Question

Do I have to worry about removing event listeners assigned to local variables?

Consider the following sample:

var zipUtil = new ZipUtil();
zipUtil.ProgressChanged += ZipUtil_ProgressChanged;

I’m creating an instance of the ZipUtil class which is stored as a local variable within a method. Do I have to remove the listener (zipUtil.ProgressChanged -= ZipUtil_ProgressChanged;) before the method terminates or is it okay to skip the step?

Answer 1

No, you don’t have to remove that event handling method.

When adding an event handler to an event, a reference from the (object containing the) event to the event handler is created, not the other way round. Once zipUtil goes out of scope, the event handler will not make any difference pertaining to references to zipUtil.