Ops! I forgot one!

[Lobo]

Hey, and what about the "VBMsoStdCompMgr" window? Does anyone have an idea
about it?


Lobo.
Soon: VBFX - http://www.fatorx.com.br


Dan Appleman <dan@desaware.com> wrote in message
news:38F41A16.AC2DB493@desaware.com...
>
>
> Lobo wrote:
>
> > Hi Dan,
> >
> > I have three questions for you:
> >
> > 1) Recently I had a real problem. I started building a class that would
> > receive a TextBox and a CommandButton controls. Then, I would set their
> > references to two private variables that used the 'WithEvents' keyword
to
> > handle their events. Well, these worked just fine, but, it just doesn't
fit
> > when the controls I'm trying to pass by are part of an array. It seems
that
> > VB implements/inherits an interface to the controls that are part of an
> > array to get the 'Index' parameter on the events, besides the other
features
> > of a collection. So, this error comes up: Error 459 - 'Object or class
does
> > not support the set of events'. I've tried to figure it out without any
> > success. Any idea??
> >
>
> Thou shalt not pass references to controls as parameters to classes. I've
heard
> of all sorts of problems when
> people do this.
> I know that's not the answer you want to hear, but I really would suggest
you
> reevaluate your design.
>
> >
> > 2) How much do you know about those hidden windows that VB creates
(their
> > classes names: "OleDdeWndClass 0x########", "OleMainThreadWndClass
> > 0x########", "VBMsoStdCompMgr", "VBBubbleRT6", "ThunderRT6Main",
> > "VBFocusRT6")? 'Cause I know just a little... Do you know where we can
find
> > some information about them? (it seems that MSDN doesn't have too much
thing
> > about it)
> >
>
> None of these are documented, but I know a little bit about a couple of
them.
> ThunderRT6Main is the main hidden window for your VB application (every VB
> application has one - it's the main
> top level application window - see my Win32 API book for a bit more about
this
> window).
> OleMainThreadWndClass is one of the windows that is used to marshal COM
method
> calls. Marshaling on a local system is handled internally by a sent or
posted
> message.
> I suspect OleDdeWndClass is the window used for DDE messages (DDE is also
a
> SendMessage/PostMessage based protocol under the hood).
> I have no idea what the other two are. VBBubbleRT6 seems especially
interesting.
> Anyone have an idea?
>
> >
> > 3) I was trying to figure out how the strings are handled in VB. The
> > variable-length string was just straightforward: using 'VarPtr' function
you
> > get the pointer to where the real data is stored (just the same pointer
you
> > would get using 'StrPtr' function), and, the string is allocated in a
new
> > place every time you make a change to it. So, I thought that the
> > fixed-length string would be just the same, with the difference that the
> > pointer where the real data stands would never change. But, it was not
like
> > that. With the 'StrPtr' I always can get the data but its pointer is
always
> > changing and couldn't figure out how to get this one only by using the
> > 'VarPtr' function... Can you give me the light?? (Note, this is just a
> > matter of understanding some VB's internals)
> >
>
> Almost everything you ask here is covered in incredible detail in my
previous
> book "Dan Appleman's Win32 API Puzzle Book and Tutorial for VB
Programmers". In
> that book you'll learn all about VarPtr, StrPtr and the magic of BSTR's
(the OLE
> subsystem strings which VB uses). Conversions from Unicode and ANSI, etc.
> As for StrPtr on fixed strings - I'm pretty sure it converts your fixed
string
> into a temporary dynamic string before returning the pointer - that's why
it's
> in a different memory location each time.
>
> Dan
>
>

[Mattias Sjögren]

>Hey, and what about the "VBMsoStdCompMgr" window? Does anyone have an idea about it?

Lobo,

I think it's a window related to COM marshaling too, used by VB on
Windows NT. Matthew Curland uses it in his threading code in the June
99 VBPJ.


Mattias

__________________________________________________
Mattias Sjögren (MCP) - mattiass @ hem.passagen.se
VB+ http://hem.spray.se/mattias.sjogren/
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