🚀 go-pugleaf

Hi Christophe,
 There are different ways and strategies to exchange data between
applications, but if U write both applications, things are quite simple!
Well if U only need to exchange a simple character the messages can be ok...
 In the sender application get a pointer to the receiver application Handle
(ex. by using FindWindow ... ) ... say it pReceiveAppHandle

 char YourChar='c'; //change it with the character U need :)

 COPYDATASTRUCT cd; //this struct can hold bigger pieces of data, but beware
of not copying pointers, Your applications run on different  address spaces
so they would be useless!!

 ZeroMemory(&cd,sizeof(cd)); //always keep things clean :)
 cd.dwData=int(YourChar); //we only need a character so use this trick, get
the ordinal number of the char by casting it to a int :-)
//here the function U need simple not?
SendMessage(pReceiveAppHandle, //the pointer to the receiver application we
mention above!
                      WM_COPYDATA,  //the kind of message we're going to
send
                      (WPARAM)&cd,      //U send only the pointer to the
struct, it would be a burden for windows to send all the stuff
                      (LPARAM)Handle);  //U may find useful to receive the
sender application Handle from the receiver application, this parameter
allows that!

Now come to the receiver application:
There are several ways to manage Application Messagges ... I'll opt for
overriding the Form Messages Handler:
In the header place this function declaration:
  void __fastcall WndProc(Messages::TMessage &Message);

In the C++ file implement it:

void __fastcall TForm1::WndProc(Messages::TMessage &Message)
{

        if(Message.Msg == WM_COPYDATA   ) //Remember this is the kind of
message we used to send data:)
        {


           COPYDATASTRUCT *pCD = (COPYDATASTRUCT *)Message.WParam;
//Remember we only sent the pointer to that struct
           ShowMessage("Character arrived: "+AnsiString(char(pCD->dwData)));
//We have to reverse the trick used to send a character through a integer,
just cast back the ordinal number of Your character to a char

                return;
        }

        TForm::WndProc(Message); // We only need to handle the  WM_COPYDATA
message type, so leave the application to handle all the ramain.N.B. If U
don't do this no message (there are tons of messages example the ones for
repainting ...) will pass and Your application will hang!!!
}


This is all U need, but keep in mind that there are a lot of other ways ...
another simple one can be through Windows Clipboard!:)

See U!
Stefano B.



FindWindow
"Christophe MINETTI" <cminetti@ulb.ac.be> ha scritto nel messaggio
news:41824B51.804A82A5@ulb.ac.be...
> Hi all,
>
> I have two different applications running and I would like them to
> exchange a character. I know this should be possible with Windows
> messages but I am not familiar with this stuff. If someone has a simple
> way to implement it, I would greatly appreciate.
>
> Thanks in advance
>
> Christophe
>
>