acmDriverMessage - Win32 Multimedia Programmer's Reference

Custom Search

	Overview

	Group

	Quick Info

acmDriverMessage

The acmDriverMessage function sends a user-defined message to a given ACM driver instance.

LRESULT acmDriverMessage(

HACMDRIVER had,
UINT uMsg,
LPARAM lParam1,
LPARAM lParam2
);

Parameters
had

Handle of the ACM driver instance to which the message will be sent.

uMsg

Message that the ACM driver must process. This message must be in the ACMDM_USER message range (above or equal to ACMDM_USER and less than ACMDM_RESERVED_LOW). The exceptions to this restriction are the ACMDM_DRIVER_ABOUT, DRV_QUERYCONFIGURE, and DRV_CONFIGURE messages.

lParam1 and lParam2

Message parameters.

Return Values
The return value is specific to the user-defined ACM driver message specified by the uMsg parameter. However, possible error values include the following:

MMSYSERR_INVALHANDLE	The specified handle is invalid.
MMSYSERR_INVALPARAM	The uMsg parameter is not in the ACMDM_USER range.
MMSYSERR_NOTSUPPORTED	The ACM driver did not process the message.

Remarks
To display a custom About dialog box from an ACM driver, an application must send the ACMDM_DRIVER_ABOUT message to the driver. The lParam1 parameter should be the handle of the owner window for the custom About dialog box, and lParam2 must be set to zero. If the driver does not support a custom About dialog box, MMSYSERR_NOTSUPPORTED will be returned and it is the application's responsibility to display its own dialog box. For example, the Control Panel Sound Mapper option will display a default About dialog box based on the ACMDRIVERDETAILS structure when an ACM driver returns MMSYSERR_NOTSUPPORTED. An application can query a driver for custom About dialog box support without the dialog box being displayed by setting lParam1 to

1L. If the driver supports a custom About dialog box, MMSYSERR_NOERROR will be returned. Otherwise, the return value is MMSYSERR_NOTSUPPORTED.

User-defined messages must be sent only to an ACM driver that specifically supports the messages. The caller should verify that the ACM driver is the correct driver by retrieving the driver details and checking the wMid, wPid, and vdwDriver members of the ACMDRIVERDETAILS structure.

Never send user-defined messages to an unknown ACM driver.

See Also
DRV_QUERYCONFIGURE, DRV_CONFIGURE, ACMDRIVERDETAILS

Last news from Greatis Software

    Nostalgia .Net     .Net is powerful, but not all-powerful, so sometimes we need to use Win32 API for our .Net applications. It's simple enough with Platform Invoke if you have Win32 skill, but we do not always have time to dig the ancient documentation, declare the special types that are compatible with Win32, find the values of the Win32's constants and so on. Nostalgia .Net offers several simple-to-use classes, and components that will allow you to forget about the headache of Win32 and just use the power of Win32 in your application the same way as you use the native. Net classes. More »

Recommended software for developers

    Ultimate Pack     Component pack for Delphi and C++ Builder that contains runtime form designer, runtime object inspector, print suite and much more for the very special price. More »

    Form Designer .Net     Unique runtime form design solution that allows to edit any form in .Net WinForms application at runtime with full source codes for only 300 euro! More »

    Print Suite .Net     Print Suite .Net is a set of components for easy printing texts, images and grids from your WinForms applications. Full C# source codes are available More »

    Gradient Controls .Net     Gradient Controls .Net offers controls with gradient background feature. Labels, panels and so on... Full C# source codes are available More »

    Greatis iGrid     iGrid plots drawing grid right over your desktop, so you can use it everywhere, with any drawing application without any special plugins for different graphic editors. More »

All the contacts and projects

Dmitry Vasiliev (just.dmitry)

More Online Helps

Win32 Programmer's Reference
Win32 Multimedia Programmer's Reference
OLE Programmer's Reference
Microsoft Windows Pen API Programmer's Reference
Microsoft Windows Sockets 2 Reference
Microsoft Windows Telephony API (TAPI) Programmer's Reference
Unix Manual Pages

greatis just4fun network