private static int GetTokenOffsetFromBlob(IntPtr blob)
{
Debug.Assert(blob != IntPtr.Zero);
IntPtr tokenPointer = Marshal.ReadIntPtr(blob, (int)Marshal.OffsetOf <HttpApiTypes.HTTP_REQUEST_CHANNEL_BIND_STATUS>("ChannelToken"));
Debug.Assert(tokenPointer != IntPtr.Zero);
return((int)IntPtrHelper.Subtract(tokenPointer, blob));
}
public void IntPtrSubtractTest()
{
int[] arr = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 };
unsafe
{
fixed(int *parr = arr)
{
// Get the size of an array element.
const int size = sizeof(int);
var ptr = IntPtrHelper.Add(new IntPtr(parr), size * (arr.Length - 1));
var index = arr.Length - 1;
for (var ctr = 0; ctr < arr.Length; ctr++)
{
var newPtr = IntPtrHelper.Subtract(ptr, ctr * size);
Assert.AreEqual(arr[index], Marshal.ReadInt32(newPtr));
index--;
}
}
}
}
