IVIO_Ioctl::DoCommand

This method performs the direct communication with the device driver.

Syntax

HRESULT IVIO_Ioctl::DoCommand( DWORD dwCommandId, const PVOID pCommandData, DWORD cb, PVOID pReply, DWORD dwOutputSize, DWORD *pReplySize );

Parameters

dwCommandId
[in] Specifies the device-driver command identifier. This information is furnished by the provider of the VIO hardware device driver.
pCommandData
[in] Pointer to a buffer that contains driver-specific data for the given command specified in dwCommandId.
cb
[in] Size of the buffer referenced by the pCommandData parameter.
pReply
[out] Pointer to a buffer that stores information returned by the device driver.
dwOutPutSize
[in] Specifies the size of the buffer referenced by the pReply parameter.
pReplySize
[out] Pointer to a DWORD value that contains the size of the data set stored in the buffer referenced by pReply.

Return Values

One of the values described in the following table is returned.

Value
Description
S_OK The function was executed successfully. Reply data from the device driver is stored in the pReply buffer.
E_POINTER Either the pCommandData, pReply, or pReplySize pointer is invalid.
E_INVALID The value in dwCommandId is invalid for the device driver or the value given in dwOutputSize is too small for the amount of data in the reply. The correct size is stored in the value referenced by pReplySize.
E_UNEXPECTED An unexpected error occurred in the request to the device driver.