Calling GetRawInputDeviceList function in LabVIEW

Question

Hi,
I want to call GetRawInputeviceList function in the User32.dll using LabVIEW, but I am having difficulty in understandign the function prototype. To be specific, I am not clear what LabVIEW data types to be created for the arguments in the function. I went through this link http://msdn.microsoft.com/en-us/library/windows/desktop/ms645598(v=vs.85).aspx to understand the function prototype, but it is confusing.
Thanks

Answer 1

I created a LabVIEW Example based off of the example on the MSDN. 
Most of the datatypes for this example boil down to unsigned ints 32-bit.  See Windows Data Types for more info.  It should also be noted that I use a hardcoded "8" for the sizeof(RAWINPUTDEVICELIST).  This is because each of the child elements are 4-byte integers.  You could check this by downloading Visual Studio and using "printf("%d\n", sizeof(RAWINPUTDEVICELIST);".
C++:
The following sample code shows a typical call to GetRawInputDeviceList:
UINT nDevices;
PRAWINPUTDEVICELIST pRawInputDeviceList;
if (GetRawInputDeviceList(NULL, &nDevices, sizeof(RAWINPUTDEVICELIST)) != 0) { Error();}
if ((pRawInputDeviceList = malloc(sizeof(RAWINPUTDEVICELIST) * nDevices)) == NULL) {Error();}
if (GetRawInputDeviceList(pRawInputDeviceList, &nDevices, sizeof(RAWINPUTDEVICELIST)) == (<dtype rid="UINT"/>)-1) {Error();}
// do the job...
// after the job, free the RAWINPUTDEVICELIST
free(pRawInputDeviceList);
LabVIEW:
In case the snippet doesn't work, I also attached the VI.
*Note:  It should also be noted that my error checking is very minimal.  I check for the "-1" output on the first call to the function, but I really should use the Kernel32.dll to call GetLastError() as necessary.  This is obviously a simplistic example.
EDIT:
If you have any specific questions about the code or function prototyping, feel free to ask.  I'll be honest, this example took me a long while to replicate.  Getting the structure to pass correctly took some trial-and-error
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Attachments:
GetRawInputDeviceList.vi ‏11 KB