[Okta Webinar] Learn how to a build a cloud-first strategyRegister Now

x
?
Solved

waveOutOpen () callback function problem

Posted on 1997-03-23
1
Medium Priority
?
1,797 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 400 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

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

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

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…
The uses clause is one of those things that just tends to grow and grow. Most of the time this is in the main form, as it's from this form that all others are called. If you have a big application (including many forms), the uses clause in the in…
Integration Management Part 2
When cloud platforms entered the scene, users and companies jumped on board to take advantage of the many benefits, like the ability to work and connect with company information from various locations. What many didn't foresee was the increased risk…
Suggested Courses

872 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