GET MESSAGE (IE DATA) FROM ANOTHER APPLICATION
Date sent: Wed, 24 Feb 1999 16:27:35 -0500
From: Brad Stowers
To: Delphi@Kyler.com
Subject: Re: Getting a message from another app
Send reply to: Delphi@Kyler.com
> var
> cds : TcopyDataStruct;
> Hwnd : Thandle;
> begin
> cds.dwData := Top;
> cds.cbData := length('Hello')+1;
> getmem (cds.lpData , pchar('Hello'));
> strcopy (cds.lpData , pchar('Hello');
> Hwnd := FindWindow('Tform1','Form1');
> if Hwnd <> 0 then
> SendMessage ( Hwnd , WM_RECEIVE_NOTIFICATION , Cardinal(@cds))
> end;
> and at the get data you have to make the following
> procdure getdata (var msg : TwmCopyData); message M_RECEIVE_NOTIFICATION;
> and at it's implementation you add
> procedure getdata (var msg : TwmCopyData);
> begin
> ... work with data
> end;
Don't forget to free memory that you allocate:
> var
> cds : TcopyDataStruct;
> Hwnd : Thandle;
> begin
> cds.dwData := Top;
> cds.cbData := length('Hello')+1;
> getmem (cds.lpData , pchar('Hello'));
> strcopy (cds.lpData , pchar('Hello');
> Hwnd := FindWindow('Tform1','Form1');
> if Hwnd <> 0 then
> SendMessage ( Hwnd , WM_RECEIVE_NOTIFICATION , Cardinal(@cds))
freemem(cds.lpdata);
> end;
If you use PostMessage instead of SendMessage it gets messier. Generally,
in that case, you would free the memory in the "poster" if PostMessage
failed, and free it in the "receiver" if it didn't. With SendMessage you
don't have to worry about it since SendMessage won't return until after the
message has been processed (the data has been used).
Regards,
Brad Stowers
Delphi Free Stuff -- http://www.delphifreestuff.com/
"If you're a professional Delphi programmer who hasn't read the
Object Pascal Language Guide, then you're not."
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