HidP_GetUsageValue function (hidpi.h)
The HidP_GetUsageValue routine extracts the data associated with a HID control value that matches the selection criteria in a HID report.
Syntax
NTSTATUS HidP_GetUsageValue(
[in] HIDP_REPORT_TYPE ReportType,
[in] USAGE UsagePage,
[in] USHORT LinkCollection,
[in] USAGE Usage,
[out] PULONG UsageValue,
[in] PHIDP_PREPARSED_DATA PreparsedData,
[in] PCHAR Report,
[in] ULONG ReportLength
);
Parameters
[in] ReportType
Specifies a HIDP_REPORT_TYPE enumerator value that identifies the report type.
[in] UsagePage
Specifies the value's usage page.
[in] LinkCollection
Specifies the link collection that contains the value. If LinkCollection is nonzero, the routine only searches for the usage in this link collection; otherwise, if LinkCollection is zero, the routine searches for the usage in the top-level collection associated with PreparsedData.
[in] Usage
Specifies the usage of the value.
[out] UsageValue
Pointer to a buffer in which the routine returns the value data.
[in] PreparsedData
Pointer to a top-level collection's preparsed data.
[in] Report
Pointer to a report that contains values.
[in] ReportLength
Specifies the length, in bytes, of the report located at Report.
Return value
HidP_GetUsageValue returns one of the following status values:
| Return code | Description |
|---|---|
|
The routine successfully returned the value data. |
|
The report length is not valid. |
|
The specified report type is not valid. |
|
The collection contains a value on the specified usage page in a report of the specified type, but there are no such usages in the specified report. |
|
The preparsed data is not valid. |
|
The collection does not contain a value on the specified usage page in any report of the specified report type. |
Remarks
HidP_GetUsageValue does not sign or scale the value. To extract a signed value, use HidP_GetScaledUsageValue. To manually assign the sign bit, the position of the sign bit can be determined from the information in a value's HIDP_VALUE_CAPS structure.
HidP_GetUsageValue is designed to extract a usage value for a usage whose report count is 1. If the specified usage has a report count greater than 1, the usage is part of a usage value array. HidP_GetUsageValue only returns the first data item in a usage value array. To extract all data items in a usage value array, use HidP_GetUsageValueArray.
For more information, see HID Collections.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Available in Windows 2000 and later versions of Windows. |
| Target Platform | Universal |
| Header | hidpi.h (include Hidpi.h) |
| Library | Hidparse.lib |
| IRQL | <= DISPATCH_LEVEL |