关于C#使用C++嵌套结构体的问题.请教一下各位

langyue555 2015-04-30 11:11:32

最近做一个项目,要使用的C++的dll,遇到复杂结构的结构体,返回结果总是不对,请各位帮忙看看
C++的结构体:



typedef struct CMS_GUID {

	unsigned long  Data1;

	unsigned short Data2;

	unsigned short Data3;

	unsigned char  Data4[ 8 ];

}*LPCMS_GUID;

#endif

/**@brief 镜头列表节点结构 */

typedef struct CMS_NodeData

{

	NODE_HANDLE hNode;			/**  节点HANDLE */

	int			nNodeID;		/**	 节点ID		*/

	int			nNodeType;		/**  节点类型	*/

	int			nStatus;		/**  节点状态 0 :禁用; 1: 可用*/	

	int			bPTZ;			/**  是否云台	*/

	int			nPTZType;		/**  云台类型	*/

	int			nPTZAddr;		/**  云台地址	*/

	CMS_GUID	devGUID;		/**  镜头GUID	*/

	char		cName[64];		/**  节点名称	*/

	char		cDescribe[200];	/**  节点描述	*/

}*LPCMS_NodeData;

我定义的C#结构体:



   /// <summary>

   /// 节点数据结构体

   /// </summary>

   [StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]

   public struct CMS_NodeData

   {

      // 错误	8	“SAGA.VideoSurveillanceSystems.Client.Common.CMS_NodeData.DevGUID”: 标记为 StructLayout(LayoutKind.Explicit) 的实例字段类型必须具有 FieldOffset 特性	E:\昆明看守所监控\3实现\05Code\VideoSurveillanceSystems\SAGA.VideoSurveillanceSystems.Client.Common\Devices.cs	61	22	SAGA.VideoSurveillanceSystems.Client.Common



       public IntPtr NodeHandle;

       public int NodeID;

       public int NodeType;

       public int Status;

       public int PTZ;

       public int PTZType;

       public int PTZAddr;

       public LPCMS_GUID DevGUID;

       [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 64)]

       public string NodeName;

       [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 200)]

       public string NodeDescribe;



   }

    /// <summary>

    /// 镜头GUID

    /// </summary>

   [StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]

   public struct LPCMS_GUID 

   {

       public uint Data1;

       public UInt16 Data2;

       public UInt16 Data3;

       [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]  

       public byte[] Data4;





   }

C++的函数定义:



/**@brief 得到第一个节点指针

* @param [IN]	hServer			服务器句柄。

* @param [OUT]	pData			节点数据结构指针，参见：LPCMS_NodeData。

* @return 返回如下错误码：

*         #成功，NOZERO

*         #失败，ZERO

* @note

*/

extern int __stdcall CMS_GetFirstNode(IN SERVER_HANDLE hServer,OUT LPCMS_NodeData pData);

C#的函数定义



       [DllImport("CMS_ClientComm.dll", EntryPoint = "CMS_GetFirstNode", ExactSpelling = false, CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Unicode)]

       private static extern int CMS_GetFirstNode(ref IntPtr hLID, ref CMS_NodeData pData);

这样调用:



       public static List<CMS_NodeData> GetAllNode() 

       {

           List<CMS_NodeData> lstNode = new List<CMS_NodeData>();



           //获取第一个节点

           CMS_NodeData firstData=new CMS_NodeData();

           LPCMS_GUID guid =new LPCMS_GUID();

           IntPtr prGuid = StructOP.StructToBytes(guid);

          IntPtr pr = StructOP.StructToBytes(firstData);

          firstData.DevGUID = guid;

          int isSuccess = CMS_GetFirstNode(ref ServerInit.ServerHandle, ref firstData);

         // uint temp = ServerInit.CMS_GetLastError();

         //string eee = ErrorExport.Export(temp);

           //循环获取所有节点

     //   firstData =(LPCMS_NodeData)Marshal.PtrToStructure(pr, typeof(LPCMS_NodeData));

           return lstNode;

       }

分配内存空间的方法:



      internal static IntPtr StructToBytes(object obj)

        {

            try

            {

                //得到结构体的大小

                int size = Marshal.SizeOf(obj);

                //创建byte数组

             //   byte[] bytes = new byte[size];

                //分配结构体大小的内存空间

                IntPtr structPtr = Marshal.AllocHGlobal(size);

                //将结构体拷到分配好的内存空间

                Marshal.StructureToPtr(obj, structPtr, false);

                //从内存空间拷到byte数组

             //   Marshal.Copy(structPtr, bytes, 0, size);

                //释放内存空间

                Marshal.FreeHGlobal(structPtr);

                //返回byte数组

                return structPtr;

            }

            catch (Exception ex)

            {

                SAGA.Common.Log.Logger.Log(ex);

                return IntPtr.Zero;

            }

        }