Hey Marsel,

Thanks for the info, I was confused for a while when I couldn't find [], so I've submitted 2 defects to Autodesk: the missing [] operator and the IBitArrayCallback not being a pluggable class. Hopefully I'll hear back soon!

About the workaround, I know this has little to do with the wrapper itself, but would IBitArray.Handle be the starting point of the array in memory? I've tried casting it to an int* and then iterating over it like this:

int* start = (int*)bitArraySel.Handle.ToPointer();

for (int i = 0; i < bitArraySel.Size; i++)
{
     var test1 = bitArraySel[i];
     var test2 = start[i];
     //var test3 = *(start + i);
}

This isn't really working and I assume it's because I need to cast it to something else than int*. I assumed it stored ints as the [] returned ints and Marshal.SizeOf(bitArraySel[i]) returns 4, just like sizeof(int) does. 

Thanks! I've tried the NativePointer method too, unfortunately it's still not working. I was only using the .Handle because I was testing the SizeOf(bitArrayElement) using the [] that are now missing. 

I came up with this solution, got most of the code from the C++ SDK, if anyone is having similar problems... :) (Extension method: bitArray.GetBit(i))

public static class IBitArrayExtensions
{
private const int NSHIFT = 6;
private const int CHAR_BIT = 8;
private const int kMAX_LOCALBITS = CHAR_BIT*sizeof (ulong);

private const int BITS_PER_DWORD_PTR = (CHAR_BIT*sizeof (ulong));
private const int BITS_PER_DWORD_PTR_MASK = BITS_PER_DWORD_PTR - 1;

public static unsafe int GetBit(this IBitArray bitArray, int index)
{
//Number of bits in the bitArray
int numBits = bitArray.Size;

//Pointer to the start of either DWORD_PTR* bits or DWORD_PTR localBits
//DWORD_PTR is of type ulong
void* nativePtr = bitArray.NativePointer.ToPointer();

//Determines whether we use bits or localBits
bool useLocal = numBits <= kMAX_LOCALBITS;

if (useLocal)
{
ulong localBits = ((ulong*)nativePtr)[0];
ulong bitMask = (index < kMAX_LOCALBITS) ? (((ulong)1) << index) : 0;
return ((localBits & bitMask) != 0) ? 1 : 0;
}
else
{
ulong* bits = ((ulong**)nativePtr)[0];
int bitIndex = index >> NSHIFT;
var bitMaskParameter = index & BITS_PER_DWORD_PTR_MASK;
ulong bitMask = (bitMaskParameter < kMAX_LOCALBITS) ? (((ulong)1) << bitMaskParameter) : 0;
return ((bits[bitIndex] & bitMask) != 0) ? 1 : 0;
}
}
}

Hey aandres, I think in later versions of the wrapper the .Handle property has been changed to NativePointer. So maybe you could try and replace .NativePointer to .Handle