DDECallback with Delphi 7 on win7 64 bits machine

[vincdp]

I have a problem with a DDECallback function in an old application that now should be ran on 64 bits machines.
It uses pointers, and pointers management is not the same when you go to 64 bits machines.

The application must wait for an operation to be finished by the DDE server application (not Delphi).

My tests on WM_DDE_ACK and WM_DDE_TERMINATE do not work anymore.

Can someone help me with a DDECallback function for win 64 bits ?

Thanks !

function SVDdeCallBack(
CallType, Fmt : UINT; //transaction type ; format atom of the data sent from the server
Conv: HConv; //a handle the conversation
hsz1, hsz2: HSZ; // hsz1: topic name ; hsz2: item name
Data: HDDEData; //a handle to the data associated with the topic and item name pair
Data1, Data2: DWORD) //
: HDDEData; stdcall;
var
pData: Pointer;
Len: Integer;
begin
Result := 0;
// Check if the calltype is the monitoring DDE call
if CallType = XTYP_MONITOR then
begin
// Get the DDE data
pData := DdeAccessData(Data, @Len);
// I got here for pData a totally different value size than on the 32 bits machine
if pData <> nil then
begin
// If data is a posted message
if Data2 = MF_POSTMSGS then
begin
try
// Check if the message was an acknowledge message
if TMonMsgStruct(pData^).wMsg = WM_DDE_ACK then
begin
// Detect only the acknowledge messages with no busy flag
if ((TMonMsgStruct(pData^).dmhd.uilo and DDE_FACK) = DDE_FACK) and
((TMonMsgStruct(pData^).dmhd.uilo and DDE_FBUSY) = 0) then
begin
// The DDE command has terminated
// ApplData.Waitstat is a "global" variable in the application
ApplData.WaitStat := False;
end
else
begin
// Acknowledge with BUSY Flag <> 0'
end;
if TMonMsgStruct(pData^).wMsg = WM_DDE_TERMINATE then
begin
//DDE_terminate message');