long WINAPI  SMS_Send_Back_By_Sync(long pAppData);//接口



typedef struct      

{

      char telNum[22];   

      int msgLen; 

      char content[256]; 

      char dcs;               



      short sNet;          

      int serviceID;       

      int reserved;        

      int irecid;          

      int miSendType;  

      short Dest_Port; 

      short Orig_Port; 

} SMS_APP_BACK_SYNC;

       [DllImport("SMSDLL.dll", CharSet = CharSet.Auto)]

        public static extern int SMS_Send_Back_By_Sync(IntPtr pAppData);

        

        public struct SMS_APP_BACK_SYNC

        {

            public char[] telNum;  

            public int msgLen; 

            public char[] content; 

            public char dcs;               



            public Int16 sNet;          

            public int serviceID;      

            public int reserved;      

            public int irecid;       

            public int miSendType;  

            public Int16 Dest_Port; 

            public Int16 Orig_Port; 

        }

           public static void sendTo()

        {

            SMS_APP_BACK_SYNC pAppData1= new SMS_APP_BACK_SYNC();

            IntPtr pAppData = Marshal.AllocHGlobal(Marshal.SizeOf(pAppData1));

            Marshal.StructureToPtr(pAppData1, pAppData, false);



            pAppData1 = Marshal.PtrToStructure(ptr, typeof(SMS_APP_BACK_SYNC));



            char[] tempTelNum = new char[22];

            char[] tempContent = new char[256];

            tempTelNum = "123456".ToCharArray();

            tempContent = "123456".ToCharArray();

            pAppData1.telNum = tempTelNum;

            pAppData1.msgLen = smsStr.Length;

            pAppData1.content = tempContent;

            pAppData1.dcs = '0';			

            pAppData1.sNet = 0;

            pAppData1.serviceID = 0;

            pAppData1.reserved = 0;

            pAppData1.irecid = 0;

            pAppData1.miSendType = 1;

            pAppData1.Dest_Port = 0;

            pAppData1.Orig_Port = 0;



            int res = 1;

            try

            {

                res = SMS_Send_Back_By_Sync(pAppData);

             }

            ....