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Opening the Pen Driver
Before sending a driver a message, an application must first obtain a handle
to the driver with the Windows OpenDriver function. The following code demonstrates this:
HDRVR hDrvPen;
.
.
.
hDrvPen = OpenDriver( "pen", NULL, NULL );
if( hDrvPen == NULL )
{
// The pen driver does not exist.
// Either display an error message and exit,
// or continue to function as a pen-unaware application.
}
As an example of how to send the driver messages, the following code uses the
pen driver message DRV_SetPenSamplingRate to set the sampling rate to 200
points per second. A later segment of code then queries the driver to get relevant
pen infor-mation.
WORD wOldRate;
wOldRate = SendDriverMessage( hDrvPen, // Driver handle
DRV_SetPenSamplingRate, // Message
200, // New rate in Hz
NULL ); // Not applicable
.
.
.
// Get information about the pen driver
PENINFO pi;
BOOL PenHardwareExists;
fPenHardwareExists = SendDriverMessage( hDrvPen,
DRV_GetPenInfo,
(DWORD)(LPPENINFO)&pi,
NULL );
When finished, an application must close the handle to the installable driver
with the CloseDriver function, as shown here:
CloseDriver( hDrvPen, NULL, NULL );
Related Links
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More Online Helps
Win32 Programmer's Reference (win32.hlp)
Win32 Multimedia Programmer's Reference (mmedia.hlp)
OLE Programmer's Reference (ole.hlp)
Microsoft Windows Sockets 2 Reference (sock2.hlp)
Microsoft Windows Telephony API (TAPI) Programmer's Reference (tapi.hlp)
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