The WIM_OPEN message is sent to a waveform-audio input callback function when a waveform-audio input device is opened.
WIM_OPEN
dwParam1 = reserved
dwParam2 = reserved
This message does not return a value.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in mmsystem.h.
Waveform Audio Overview, Waveform Messages