HidP_UsageAndPageListDifference
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8/28/2008
This function returns the difference between two arrays of HID extended usages.
Syntax
NTSTATUS HidP_UsageAndPageListDifference(
PUSAGE_AND_PAGE PreviousUsageList,
PUSAGE_AND_PAGE CurrentUsageList,
PUSAGE_AND_PAGE BreakUsageList,
PUSAGE_AND_PAGE MakeUsageList,
ULONG UsageListLength
);
Parameters
- PreviousUsageList
[in] Pointer to a list of usages that the function compares with the list of usages in CurrentUsageList.
- CurrentUsageList
[in] Pointer to a list of usages that the function compares with the list of usages in PreviousUsageList.
- BreakUsageList
[out] Pointer to a caller-allocated buffer that, on return, contains a list of the usages that are in PreviousUsageList, but not in CurrentUsageList.
- MakeUsageList
[out] Pointer to a caller-allocated buffer that, on return, contains a list of the usages that are in CurrentUsageList, but not in PreviousUsageList.
- UsageListLength
[in] Length, in array elements, of the buffers provided at CurrentUsageList and PreviousUsageList.
Return Value
HidP_UsageAndPageListDifference returns HIDP_STATUS_SUCCESS.
Remarks
The terms button and usage are used synonymously.
A HID client can use this function to compare two lists of extended usages, for example, to determine the change in button state between two usage lists returned by two HidP_GetButtons.
If the input usage lists have different lengths, an application or driver should set UsageListLength to the length of the larger list.
The function interprets a zero usage in an input usage list as a delimiter that ends the list. Any usages after a zero in a list are not processed. The function sets unused usages at the end of the output lists to zero.
Requirements
| Header | hidpi.h |
| Library | Hidparse_lib.lib |
| Windows Embedded CE | Windows CE .NET 4.2 and later |