Why the Difference in Nomenclature?

Question

Why is it that in .aspx pages all events are preceded with "On" e.g. "OnClick", "OnCommand" and in the code-behind file they are referred "Click", "Command"? Just Naming Convention or is there some logical explanation?

Answer 1

The names of the events themselves are Click, Change, etc... The internal methods to fire those events from code are prefixed with "On" as a naming convention. In ASP.NET markup, you use the attribute OnClick but what you're really doing is wiring a method to the "Click" event. Therefore, the method autogenerated for you by VS is ButtonName_Click. This method is internally passed as a delegate to the event itself.