HidP_GetUsagesEx (Windows Embedded CE 6.0)

1/6/2010

This function returns a list of the HID control button usages that are set to On in a HID report.

Syntax

NTSTATUS HidP_GetUsagesEx(
  HIDP_REPORT_TYPE ReportType,
  USHORT LinkCollection,
  PUSAGE_AND_PAGE ButtonList,
  ULONG* UsageLength,
  PHIDP_PREPARSED_DATA PreparsedData,
  PCHAR Report,
  ULONG ReportLength
);

Parameters

• ReportType
  [in] HIDP_REPORT_TYPE enumerator value that identifies the report type.

• LinkCollection
  [in] Link collection of the button usages. If LinkCollection is nonzero, the function only returns information about the buttons that this link collection contains; otherwise, if LinkCollection is zero, the function returns information about all the buttons in the top-level collection associated with PreparsedData.

• ButtonList
  [out] Pointer to a caller-allocated buffer that this function uses to return the usage and usage page identifiers for each button that is set to On (one).

• UsageLength
  [in, out] On input, the length in array elements of the ButtonList buffer. On output, the number of usages that are currently set to On in the specified report.

• PreparsedData
  [in] Pointer to a top-level collection's preparsed data.

• Report
  [in] Pointer to a report that contains button data.

• ReportLength
  [in] Length, in bytes, of the report located at Report.

Return Value

The following table shows the possible return values.

Remarks

The terms button and usage are used synonymously.

HID clients call HidP_MaxUsageListLength to determine the maximum number of buttons that this function can return for a specified report type. Alternatively, applications or drivers can call HidP_GetUsagesEx and set UsageList to zero to return the required length in UsageLength.

Applications or drivers determine the required report length from the XxxReportByteLength members in a top-level collection's HIDP_CAPS structure.

Requirements

See Also

Reference

HID Parser Functions
HIDP_CAPS
HidP_GetButtons
HidP_GetButtonsEx
HidP_GetCaps
HidP_GetScaledUsageValue
HidP_GetUsageValue
HidP_GetUsageValueArray
HidP_MaxUsageListLength
HIDP_REPORT_TYPE
USAGE_AND_PAGE