Installing
Custom I/O Procedures
To install an
I/O procedure associated with the .ARC filename extension, use the mmioInstallIOProc function as follows:
mmioInstallIOProc (mmioFOURCC('A', 'R', 'C', ' '),
(LPMMIOPROC)lpmmioproc, MMIO_INSTALLPROC);
When you
install an I/O procedure using mmioInstallIOProc, the procedure remains
installed until you remove it. The I/O procedure is used for any file you open
as long as the file has the appropriate filename extension.
You can also
temporarily install an I/O procedure by using the mmioOpen function. In this case, the
I/O procedure is used only with a file opened by using mmioOpen and is
removed when the file is closed by using the mmioClose function. To specify an I/O
procedure when you open a file by using mmioOpen, use the lpmmioinfo
parameter to reference an MMIOINFO structure as follows:
1. Set the fccIOProc member to NULL.
2. Set the pIOProc member to the
procedure-instance address of the I/O procedure.
3. Set all other members to zero (unless you are
opening a memory file, or directly reading or writing to the file I/O buffer).
Be sure to
remove any I/O procedures you have installed before you exit your application.