SetFilePointer hFile, 0, 0, FILE_END

    static extern unsafe uint SetFilePointer(

    static extern uint SetFilePointer(

    Shared Function SetFilePointer( _

    private static extern int SetFilePointer(IntPtr handle, int lDistanceToMove, out int lpDistanceToMoveHigh, uint dwMoveMethod);

    lo = SetFilePointer(handle, lo, out hi, moveMethod);

static extern bool SetFilePointerEx(IntPtr hFile, long liDistanceToMove,

public static extern bool SetFilePointerEx(

SetFilePointerEx(handle, 0, ptr, FILE_CURRENT);//ptr contains current location of file pointer. handle is a pointer to an open file handle.

If you are passing a System.Threading.NativeOverlapped struct in (for lpOverlapped) then there's no need to also call SetFilePointer or SetFilePointerEx. The offset in the OVERLAPPED structure trumps wherever the file position was previouly set to.