Edit

EVT_VHF_READY_FOR_NEXT_READ_REPORT callback function (vhf.h)

  • Article

The HID source driver implements this event call back function to use its buffering scheme for HID Input Reports, and wants to get notified when the next report can be submitted to VHF.

Syntax

EVT_VHF_READY_FOR_NEXT_READ_REPORT EvtVhfReadyForNextReadReport;

void EvtVhfReadyForNextReadReport(
  [in] PVOID VhfClientContext
)
{...}

Parameters

[in] VhfClientContext

Pointer to the HID source driver-defined context structure that the driver passed in the previous call to VhfCreate to create the virtual HID device.

Return value

None

Remarks

Virtual HID Framework (VHF) invokes this callback function to notify the HID source driver that it can submit a buffer to get the HID Input Report. After the callback is invoked, the HID source driver must call VhfReadReportSubmit only once. If a portion of the HID Input Report is still pending, the driver must wait for VHF to invoke EvtVhfReadyForNextReadReport before the driver can call VhfReadReportSubmit again.

If the HID source driver does not implement this callback function, VHF uses a default buffering policy for HID Read (Input) Reports.

Requirements

Requirement Value
Minimum supported client Windows 10
Minimum supported server None supported
Target Platform Desktop
Header vhf.h
IRQL <=DISPATCH_LEVEL

See also

Write a HID source driver by using Virtual HID Framework (VHF)