Solved

waveOutOpen () callback function problem

Posted on 1997-03-23
1
1,600 Views
Last Modified: 2008-03-17
I can't set the callback function for the waveOutOpen () windows API call. Here is my callback function:

procedure Callback (hWave: HWAVEOUT; uMsg: UINT; dwInstance:DWORD; dwParam1:DWORD; dwParam2: DWORD);
begin
  if (uMsg = MM_WOM_DONE) then
    Application.MessageBox ('done',done',mb_Ok);
end;


and here is my waveOutOpen () system call:

waveOutOpen (@AHWaveOut,
             wCount,
             @AWaveFormatEx,
             DWORD (@Callback),
             0,
             CALLBACK_FUNCTION);

This works fine without callback function. Why doesn't this work with this callback function ? The system crashes or tells me about an illegal read...

Help !
0
Comment
Question by:yragael
1 Comment
 
LVL 3

Accepted Solution

by:
sperling earned 200 total points
ID: 1334932
procedure Callback (hWave: HWAVEOUT; uMsg: UINT;
                 dwInstance:DWORD; dwParam1:DWORD; dwParam2: DWORD);


Append a stdcall; to that line.

Regards,

Erik.
0

Featured Post

Best Practices: Disaster Recovery Testing

Besides backup, any IT division should have a disaster recovery plan. You will find a few tips below relating to the development of such a plan and to what issues one should pay special attention in the course of backup planning.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

A lot of questions regard threads in Delphi.   One of the more specific questions is how to show progress of the thread.   Updating a progressbar from inside a thread is a mistake. A solution to this would be to send a synchronized message to the…
Creating an auto free TStringList The TStringList is a basic and frequently used object in Delphi. On many occasions, you may want to create a temporary list, process some items in the list and be done with the list. In such cases, you have to…
This video shows how to use Hyena, from SystemTools Software, to bulk import 100 user accounts from an external text file. View in 1080p for best video quality.
Established in 1997, Technology Architects has become one of the most reputable technology solutions companies in the country. TA have been providing businesses with cost effective state-of-the-art solutions and unparalleled service that is designed…

803 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question