fpc and dde lazarus / 67-Windows ---------------------------------------------------------------------- peverix · 2015-12-23 08:30 Hello I try to convert a delphi 7 program that acts as a dde client to communicate with a dde server from another company. It is a command line util. I need to use the dde callback function to know when the action is finished by the other program. I ported parts of TDDEClientConv to fpc and the dde server receives the ExecuteMacros that i send. I addes a while loop to wait , but i don't receive the callback. Proberly i need to procces the windows message queue for this ? Don't know how to do this. Parts of my code function DDECallback(CallType, Fmt: UINT; Conv: HConv; hsz1, hsz2: HSZ;       Data: HDDEData; Data1, Data2: DWORD): HDDEData; stdcall; begin  writeln('DDECallback');  writeln('Fmt' + inttostr(Fmt)); end; function TDDEClient.Initialise(dwFlags: DWord) : boolean;     var   Res: UINT;    begin   dwInst:=0;    Res:=DdeInitialize( @dwInst, DdeCallback, dwFlags, 0);      Result := (Res = DMLERR_NO_ERROR); end; Thanks Peter