So I have a background in ASP.NET where a button could have a click handler or a command handler and then a command argument.

That pattern was great for when you had a bunch of buttons that basically needed to execute the same block of code with only a slightly different argument.

Is there a collary in WPF?

From what I've seen of the Command in WPF is that it revolves around an action that is independent of the control that invokes it (and still doesn't provide a way to provide an argument). Which is not really what I need.