static extern uint DragQueryFile(IntPtr hDrop, uint iFile,

Declare Function DragQueryFile Lib "shell32.dll" Alias "DragQueryFileW" ( _

                uint nselected = Helpers.DragQueryFile(m_hDrop, 0xffffffff, null, 0);

                    Helpers.DragQueryFile(m_hDrop, 0, sb, sb.Capacity + 1);

    internal static extern uint DragQueryFile(uint hDrop, uint iFile, StringBuilder buffer, int cch);