We have some C++ code that we need to convert to VB.net. It calls the DeviceIOControl API and uses a char array as the output buffer. We think we need to use marshalling to do this but don't know exactly how. For example if we use
Dim outputBuffer(1000) as char
anObject = DeviceIoControl(aHandle, FSCTL_ENUM_USN_DATA, EnumDataBufferIn, Marshal.SizeOf(EnumDataBufferIn), outputbuffer, Marshal.SizeOf(outputbuffer), byteBack, 0)

It tells us that outputbuffer cannot be marshalled as a meaningful structure, no meaningul size or offset can be computed. We have tried all kinds of things to try and get around this and get different errors with everything we try.

How did you declare DeviceIoControl? If the C++ code used a char
array, you should probably use a byte array in VB (.NET Char != C++
char). And the parameter type should therefore also be a Byte().



Mattias

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Mattias Sjögren [MVP] mattias @ mvps.org
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