如何使用自定义对象从Win32 DLL调用C函数

Delphi中的函数定义:

function GetAttrbControls(    Code     : PChar;
                              InputList: TItemList;
                              var Values   : TValArray): Boolean; stdcall; export;

使用的类型:

type
  TItem = packed record
    Code : PChar;
    ItemValue: Variant;
  end;

TItemList = array of TItem;

TValArray = array of PChar;

C#(不起作用)中的示例:

[StructLayout(LayoutKind.Sequential)]
 public class Input
 {
     public string Code;
     public object ItemValue;
 };


[DllImport("Filename.dll", EntryPoint = "GetValues", CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.Cdecl)]
    public static extern bool GetValues(string Code, Input[] InputList, ref StringBuilder[] Values);