Appendix D
Watchdog Timer Programming on WinCE (TPC-2012)
D-2
ni.com
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dwIoControlCode
(in) Specifies the operation control code. 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
dwIoControlCode
parameter. However, if you write a custom device
driver, you can define
IOCTL_XXXX
control codes, per the
CTL_CODE
macro. You then can advertise these control codes, and an application
can use these control codes with DeviceIoControl to perform
driver-specific functions.
•
lpInBuffer
(in) Long pointer to a buffer that contains the data required to perform
the operation. This parameter can be NULL if the
dwIoControlCode
parameter specifies an operation that does not require input data.
•
nInBufferSize
(in) Size, in bytes, of the buffer pointed to by
lpInBuffer
.
•
lpOutBuffer
(out) Long pointer to a buffer that receives the operation’s output data.
This parameter can be NULL if the
dwIoControlCode
parameter
specifies an operation that does not produce output data.
•
nOutBufferSize
(in) Size, in bytes, of the buffer pointed to by
lpOutBuffer
.
•
lpBytesReturned
(out) Long pointer to a variable that receives the size, in bytes, of the
data stored into the buffer pointed to by
lpOutBuffer
. The
lpBytesReturned
parameter cannot be NULL. Even when an
operation produces no output data, and
lpOutBuffer
can be
NULL, DeviceIoControl makes use of the variable pointed to by
lpBytesReturned
. After such an operation, the variable value has no
meaning.
•
lpOverlapped
(in) Ignored; set to NULL.
•
Return Values
Nonzero indicates success. Zero indicates failure. To get extended
error information, call GetLastError.
