udp 网络编程服务端接收到的端口号与客户端中定义的端口号不一样，请高手指教。

server端：



#include <winsock2.h>

#include <stdio.h>



void main(void)

{

   WSADATA              wsaData;

   SOCKET               ReceivingSocket;

   SOCKADDR_IN          ReceiverAddr;

   int                  Port = 5150;

   char                 ReceiveBuf[1024];

   int                  BufLength = 1024;

   SOCKADDR_IN          SenderAddr;

   int                  SenderAddrSize = sizeof(SenderAddr);

   int                  Ret;





   // Initialize Winsock version 2.2



   if ((Ret = WSAStartup(MAKEWORD(2,2), &wsaData)) != 0)

   {

      // NOTE: Since Winsock failed to load we cannot use WSAGetLastError 

      // to determine the error code as is normally done when a Winsock 

      // API fails. We have to report the return status of the function.



      printf("ERROR: WSAStartup failed with error %d\n", Ret);

      return;

   }



   

   // Create a new socket to receive datagrams on.

 

   if ((ReceivingSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP))

       == INVALID_SOCKET)

   {

      printf("ERROR: socket failed with error %d\n", WSAGetLastError());

      WSACleanup();

      return;

   } 



   // Setup a SOCKADDR_IN structure that will tell bind that we

   // want to receive datagrams from all interfaces using port

   // 5150.



   ReceiverAddr.sin_family = AF_INET;

   ReceiverAddr.sin_port = htons(Port);    

   ReceiverAddr.sin_addr.s_addr = htonl(INADDR_ANY);



   // Associate the address information with the socket using bind.



   if (bind(ReceivingSocket, (SOCKADDR *)&ReceiverAddr, sizeof(ReceiverAddr))

       == SOCKET_ERROR)

   {

      printf("ERROR: bind failed with error %d\n", WSAGetLastError());

      closesocket(ReceivingSocket);

      WSACleanup();

      return;

   }



   printf("We are ready to receive 1 datagram from any interface on port %d...\n",

          Port);



   // At this point you can receive datagrams on your bound socket.



   if ((Ret = recvfrom(ReceivingSocket, ReceiveBuf, BufLength, 0,

       (SOCKADDR *)&SenderAddr, &SenderAddrSize)) == SOCKET_ERROR)

   {

      printf("ERROR: recvfrom failed with error %d\n", WSAGetLastError());

      closesocket(ReceivingSocket);

      WSACleanup();

      return;

   }



   printf("We successfully received %d bytes from address %s:%d.\n", Ret,

          inet_ntoa(SenderAddr.sin_addr), ntohs(SenderAddr.sin_port));





   // When your application is finished receiving datagrams close

   // the socket.



   closesocket(ReceivingSocket);



   // When your application is finished call WSACleanup.



   WSACleanup();

}











client端：

#include <winsock2.h>

#include <stdio.h>



void main(int argc, char **argv)

{

   WSADATA              wsaData;

   SOCKET               SendingSocket;

   SOCKADDR_IN          ReceiverAddr;

   int                  Port = 5150;

   int                  Ret;



   /*if (argc <= 1)

   {

      printf("USAGE: udpsender <receiver IP address>.\n");

      return;

   }*/



   // Initialize Winsock version 2.2



   if ((Ret = WSAStartup(MAKEWORD(2,2), &wsaData)) != 0)

   {

      // NOTE: Since Winsock failed to load we cannot use WSAGetLastError 

      // to determine the error code as is normally done when a Winsock 

      // API fails. We have to report the return status of the function.



      printf("ERROR: WSAStartup failed with error %d\n", Ret);

      return;

   }

   

   // Create a new socket to receive datagrams on.

 

   if ((SendingSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP))

       == INVALID_SOCKET)

   {

      printf("ERROR: socket failed with error %d\n", WSAGetLastError());

      WSACleanup();

      return;

   }



   // Setup a SOCKADDR_IN structure that will identify who we

   // will send datagrams to. For demonstration purposes, let's

   // assume our receiver's IP address is 136.149.3.29 and waits

   // for datagrams on port 5150. Obviously you will want to prompt 

   // the user for an IP address and port number and fill these 

   // fields in with the data from the user.



   ReceiverAddr.sin_family = AF_INET;

   ReceiverAddr.sin_port = htons(Port);    

   //ReceiverAddr.sin_addr.s_addr = inet_addr(argv[1]);

   ReceiverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");

   // Send a datagram to the receiver.



   if ((Ret = sendto(SendingSocket, "Hello", 5, 0, 

       (SOCKADDR *)&ReceiverAddr, sizeof(ReceiverAddr))) == SOCKET_ERROR)

   {

      printf("ERROR: sendto failed with error %d\n", WSAGetLastError());

      closesocket(SendingSocket);

      WSACleanup();

      return;

   }



   // When your application is finished sending datagrams close

   // the socket.



   printf("We successfully sent %d byte(s) to %s:%d.\n", Ret,

          inet_ntoa(ReceiverAddr.sin_addr), htons(ReceiverAddr.sin_port));



   closesocket(SendingSocket);



   // When your application is finished call WSACleanup.



   WSACleanup();

}