User manual

UNO-1019 User Manual 60
DeviceIOControl
This function sends a control code directly to a specified device driver,
causing the corresponding device to perform the specified operation.
BOOL DeviceIoControl(
HANDLE hDevice,
DWORD dwIoControlCode,
LPVOID lpInBuffer,
DWORD nInBufferSize,
LPVOID lpOutBuffer,
DWORD nOutBufferSize,
LPDWORD lpBytesReturned,
LPOVERLAPPED lpOverlapped );
Parameters:
. hDevice
[in] Handle to the device that is to perform the operation. Call the Create-
File function to obtain a device handle.
. dwIoControlCode
[in] Specifies the control code for the operation. This value identifies the
specific operation to be performed and the type of device on which the
operation is to be performed. No specific values are defined for the dwIo-
ControlCode parameter. However, the writer of a custom device driver
can define IOCTL_XXXX control codes, per the CTL_CODE macro.
These control codes can then be advertised, and an application can use
these control codes with DeviceIoControl to perform driver specific func-
tions.
. lpInBuffer
[in] Long pointer to a buffer that contains the data required to perform the
operation. This parameter can be NULL if the dwIoControlCode parame-
ter specifies an operation that does not require input data.
. nInBufferSize
[in] Size, in bytes, of the buffer pointed to by lpInBuffer.
. lpOutBuffer