IWDFIoRequest::GetDeviceIoControlParameters method (wudfddi.h)

[Warning: UMDF 2 is the latest version of UMDF and supersedes UMDF 1. All new UMDF drivers should be written using UMDF 2. No new features are being added to UMDF 1 and there is limited support for UMDF 1 on newer versions of Windows 10. Universal Windows drivers must use UMDF 2. For more info, see Getting Started with UMDF.]

The GetDeviceIoControlParameters method retrieves the request parameters for a device I/O control-type request.

Syntax

void GetDeviceIoControlParameters(
  [out] ULONG  *pControlCode,
  [out] SIZE_T *pInBufferSize,
  [out] SIZE_T *pOutBufferSize
);

Parameters

[out] pControlCode

A pointer to a variable that receives the control code that identifies the specific operation to be performed.

This parameter is optional. The driver can pass NULL if the driver does not require the information.

[out] pInBufferSize

A pointer to a variable that receives the size, in bytes, of the input data buffer for the request. To retrieve the input data buffer, the driver calls the IWDFIoRequest::GetInputMemory method.

This parameter is optional. The driver can pass NULL if the driver does not require the information.

[out] pOutBufferSize

A pointer to a variable that receives the size, in bytes, of the output data buffer for the request. To retrieve the output data buffer, the driver calls the IWDFIoRequest::GetOutputMemory method.

This parameter is optional. The driver can pass NULL if the driver does not require the information.

Return value

None

Remarks

The call to GetDeviceIoControlParameters fails if the request type is not a device I/O control type.

Although the driver can optionally specify NULL for each of the pControlCode, pInBufferSize, and pOutBufferSize parameters, the driver must specify at least one non-NULL parameter for GetDeviceIoControlParameters to execute successfully.

Requirements

See also

IWDFIoRequest

IWDFIoRequest::GetInputMemory

IWDFIoRequest::GetOutputMemory