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Perry Way · Guest

I have a need to do something a little unusual. I am writing a middle-ware
piece that needs to deliver a stream of graphic data that is only obtained
through an IPictureDisp interface. Instead of using existing DCOM for
communications (platform specific) we need to use a proprietary protocol
that rides on top of raw TCP sockets (any platform). The specifics behind
the proprietary protocol are irrelevant in this case, but even if it was
relevant we are finding zero problems/errors with the protocol. I just
bring this up so someone doesn't answer this post with "why don't you just
call CreateRemoteComObject() on your client?".

I am retrieving the picture from the COM server just fine. I can show the
image using a TPicture pointer and calling SetOlePicture(). I am assuming
that (from all the articles I've read) that since I have a pointer to the
IPictureDisp interface, I can then convert the pointer to IPicture interface
like so...

var
pd: IPictureDisp;
p: IPicture;

begin
{assignment of pd from a COM server occurs here. zero errors so far.}
p := (pd as IPicture); // no error, pointer seems valid..
p.SaveAsFile() // fails.. HRResult is invalid and cbSize is set to Zero
end;

In the roughed out example above, "p" does point to something, the address
is slightly off from the address of "pd". I can call all methods and set
properties to "p", fine thus leading me to think everything is good to go.
But when I call p.SaveAsFile(), the out variable cbSize is set to Zero! So
I am not getting the native graphic data.. BUT SetOlePicture() works..
so.... Before I go kick the dog and break things (hehe), what pray tell am I
doing wrong?

Thanks,

PW

Walter Prins · Guest

"Perry Way" <no.delphipro.spam (AT) no (DOT) spam.earthlink.net> wrote

Perry Way · Guest

"Walter Prins" wrote