Socket之UDP通信例子

悠悠小仙仙

UDP通信方式：

1，客户端不需要进行连接，而是直接访问服务器通过sendto来发送数据，recvfrom接受数据

2，服务端，不需要监听、接受等待客户端请求，当收到客户端socket通过sendto来回应客户端请求。

Client端：

1. #include <winsock2.h>  
   
2. #include <iostream>  
   
3.   
   
4. #pragma comment(lib, "WS2_32.lib")  
   
5. const unsigned int PORT = 11024;  
   
6. const int kBufferSize   = 1024;  
   
7.   
   
8. int main() {  
   
9.   
   
10.     WSADATA wsData;  
    
11.     if(WSAStartup(MAKEWORD(2, 2), &wsData) != 0) {  
    
12.         std::cout << "start up failed\n" << std::endl;  
    
13.         return 0;  
    
14.     }  
    
15.     // connect the socket;  
    
16.   
    
17.     SOCKET s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);  
    
18.     SOCKADDR_IN addIn;  
    
19.     addIn.sin_family = AF_INET;  
    
20.     addIn.sin_port = htons(PORT);  
    
21.     addIn.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");  
    
22.       
    
23.     char cSendBuffer[kBufferSize] = "Client sends a Message to the Server, please confirm?";  
    
24.     int bRecvLen = sizeof(addIn);  
    
25.     int bSendRet = sendto(s, cSendBuffer, kBufferSize, 0, (LPSOCKADDR)&addIn, sizeof(addIn));  
    
26.     while(bSendRet != SOCKET_ERROR) {  
    
27.         char cRecvBuffer[kBufferSize] = "#";  
    
28.         int bRecv = recvfrom(s, cRecvBuffer, kBufferSize, 0, (LPSOCKADDR)&addIn, &bRecvLen);  
    
29.         if(bRecv != SOCKET_ERROR) {  
    
30.             std::cout << "Client recvie the infromation from the server is: " << cRecvBuffer << std::endl;  
    
31.             ZeroMemory(cSendBuffer, kBufferSize);  
    
32.             std::cout << "please input the information the sends to the server: ";  
    
33.             std::cin >> cSendBuffer;  
    
34.             bSendRet = sendto(s, cSendBuffer, kBufferSize, 0, (LPSOCKADDR)&addIn, sizeof(addIn));  
    
35.         } else{  
    
36.             break;  
    
37.         }  
    
38.     }  
    
39.   
    
40.     if(WSACleanup() != 0) {  
    
41.         std::cout << "clean up failed\n";  
    
42.         return -1;  
    
43.     }  
    
44.     closesocket(s);  
    
45.     return 0;  
    
46. }  

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Server端：

1. #include <iostream>  
   
2. #include <winsock2.h>  
   
3.   
   
4. #pragma comment(lib, "WS2_32.lib")  
   
5.   
   
6. const unsigned int PORT = 11024;  
   
7. const int kBufferSize   = 1024;  
   
8.   
   
9. int main() {  
   
10.     WSADATA wsData;  
    
11.     if(WSAStartup(MAKEWORD(2, 2), &wsData) != 0) {  
    
12.         std::cout << "start failed" << std::endl;  
    
13.         return -1;  
    
14.     }  
    
15.     //  
    
16.     SOCKET s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);  
    
17.     SOCKADDR_IN addIn;  
    
18.       
    
19.     addIn.sin_family = AF_INET;  
    
20.     addIn.sin_port = htons(PORT);  
    
21.     addIn.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");  
    
22.     int bBindRet = bind(s, (LPSOCKADDR) &addIn, sizeof(addIn));  
    
23.     if(bBindRet != 0) {  
    
24.         std::cout << "bind failed" << std::endl;  
    
25.         return -1;  
    
26.     }  
    
27.   
    
28.     char cRecvBuffer[kBufferSize];  
    
29.     int ilen = sizeof(addIn);                 
    
30.     int iRecv = recvfrom(s, cRecvBuffer, kBufferSize, 0, (LPSOCKADDR)&addIn, &ilen);  
    
31.     while(iRecv != SOCKET_ERROR) {  
    
32.         std::cout << "recvie information: " << std::endl;  
    
33.         char cSendBuffer[kBufferSize];  
    
34.         std::cout << "Input the information that the client sends; " << std::endl;  
    
35.         std::cin >> cSendBuffer;  
    
36.         sendto(s, cSendBuffer, kBufferSize, 0, (LPSOCKADDR)&addIn, sizeof(addIn));  
    
37.     }  
    
38.   
    
39.     if(WSACleanup() != 0) {  
    
40.         std::cout << "Clean up failed" << std::endl;  
    
41.         return -1;  
    
42.     }  
    
43.   
    
44.     return 0;  
    
45. }  

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