🚀 go-pugleaf

Mike,

Simple answers to perplexing questions are the best. Thanks!

Bob

Michael Warner wrote:

> On Tue, 27 Mar 2001 19:07:40 -0800, Robert Penoyer
> <rpenoyer@earthlink.net> wrote:
>
> >I'm trying to learn to use waveInOpen. The fourth argument of this
> >function, dwCallback, is an _address_ of a "fixed callback function, an
> >event handle, or a handle of a window or thread."
> >
> >1. How do I determine the address of a function or event handle?
>
> In C/C++ you just specify its name, with no parentheses or arguments.
> You may have to cast it to the correct type, which may be DWORD for
> a multi-function argument like that one. Yuck.
>
> >2. What is a "fixed" function?
>
> The term is a bit vague, but in practice it must be a standalone
> C-style function or a static class member. Normal class members can't
> be used as callbacks, since the "this" pointer isn't available to pass
> to them.
>
> >3. How do I get the handle of a window or thread?
>
> The handle of a VCL-created windows is obtained with form->Handle.
> Threads are normally specified by thread ID, so I'm not sure about
> that one.
>
> >4. How do I invoke the event that triggers an event callback? Such an
> >event might be "buffer full."
>
> Read up on events in the API help.
>
> The callback mechanism is the easiest to use of these.