Getting an IntPtr to a ulong variable in C#

Question

I need to pass an IntPtr to IStream.Read, and the IntPtr should point to a ulong variable. How do I get this IntPtr that points to my ulong variable?

Answer 1

The best way is to change the IStream definition:

void Read([Out, MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 1)] byte[] pv,
          int cb, /*IntPtr*/ ref int pcbRead);

Then you can write

int pcbRead = 0;
Read(..., ref pcbRead);