mmioInstallIOProc
The mmioInstallIOProc function installs or removes a custom I/O procedure. This function also locates an installed I/O procedure, using its corresponding four-character code.
LPMMIOPROC mmioInstallIOProc(
FOURCC fccIOProc,
LPMMIOPROC pIOProc,
DWORD dwFlags
);
Parameters
fccIOProc
Four-character code identifying the I/O procedure to install, remove, or locate. All characters in this code should be uppercase.
pIOProc
Pointer to the I/O procedure to install. To remove or locate an I/O procedure, set this parameter to NULL. For more information about the I/O procedure, see MMIOProc.
dwFlags
Flag indicating whether the I/O procedure is being installed, removed, or located. The following values are defined.
| Value | Meaning |
| MMIO_FINDPROC | Searches for the specified I/O procedure. |
| MMIO_GLOBALPROC | This flag is a modifier to the MMIO_INSTALLPROC flag and indicates the I/O procedure should be installed for global use. This flag is ignored if MMIO_FINDPROC or MMIO_REMOVEPROC is specified. |
| MMIO_INSTALLPROC | Installs the specified I/O procedure. |
| MMIO_REMOVEPROC | Removes the specified I/O procedure. |
Return Values
Returns the address of the I/O procedure installed, removed, or located. Returns NULL if there is an error.
Requirements
** Windows NT/2000/XP:** Included in Windows NT 3.1 and later.
** Windows 95/98/Me:** Included in Windows 95 and later.
** Header:** Declared in Mmsystem.h; include Windows.h.
** Library:** Use Winmm.lib.
** Unicode:** Implemented as Unicode and ANSI versions on Windows NT/2000/XP.
See Also