C++ Socket网络编程(TCP)

基于Windows平台的Socket网络编程，用的QT，这个例子里一个服务端和一个客户端，两个应用程序之间进行通信，所以创建两个项目，目录结构如下：

直接贴代码：

服务端：

 1 // main.cpp
 2 #include <QCoreApplication>
 3 #include <iostream>
 4 #include <QDebug>
 5 #include <cstring>
 6 #include <WinSock2.h>
 7 #pragma comment(lib, "ws2_32.lib")
 8 #ifdef _WIN32
 9     typedef int socklen_t;
10 #endif
11 
12 
13 int main(int argc, char *argv[])
14 {
15     QCoreApplication a(argc, argv);
16 
17 #ifdef _WIN32
18     WSADATA wsaData;
19     if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
20         std::cerr << "Failed to initialize WinSock" << std::endl;
21         return -1;
22     }
23 #endif
24 
25 //    std::cout << "Hello World!" << std::endl;
26 //    qDebug() << "Hello World!" ;
27 
28     //创建套接字
29     int serverSocket = socket(AF_INET, SOCK_STREAM, 0);
30     if (serverSocket == -1)
31     {
32         std::cerr << "Error creating socket" << std::endl;
33         return -1;
34     }
35 
36     //准备地址结构
37     sockaddr_in serverAddress;
38     serverAddress.sin_family = AF_INET;
39     serverAddress.sin_port = htons(8888);
40     serverAddress.sin_addr.s_addr = INADDR_ANY;
41 
42     //绑定套接字
43     if (bind(serverSocket, (struct sockaddr*)&serverAddress, sizeof(serverAddress)) == -1)
44     {
45         std::cerr << "Error binding socket" << std::endl;
46 #ifdef _WIN32
47         closesocket(serverSocket);
48 #else
49         close(serverSocket);
50 #endif
51         return -1;
52     }
53 
54     //监听连接请求
55     if (listen(serverSocket, 5) == -1)
56     {
57         std::cerr << "Error listening on socket" << std::endl;
58 #ifdef _WIN32
59         closesocket(serverSocket);
60 #else
61         close(serverSocket);
62 #endif
63         return -1;
64     }
65 
66     std::cout << "Waitinig for client to connect..." << std::endl;
67 
68     //接受连接请求
69     sockaddr_in clientAddress;
70     socklen_t clientAddressLength = sizeof(clientAddress);
71     int clientScoket = accept(serverSocket, (struct sockaddr*)&clientAddress, &clientAddressLength);
72     if (clientScoket == -1)
73     {
74         std::cerr << "Error accepting connection" << std::endl;
75         closesocket(serverSocket);
76         return -1;
77     }
78 
79     std::cout << "Connection established with client" << std::endl;
80 
81     //发送和接受数据
82     char buffer[1024];
83     memset(buffer, 0, sizeof(buffer));
84     recv(clientScoket, buffer, sizeof(buffer), 0);
85     std::cout << "Received from client: " << buffer << std::endl;
86 
87     const char* message = "Hello, client!";
88     send(clientScoket, message, strlen(message), 0);
89 
90     //关闭套接字
91     closesocket(clientScoket);
92     closesocket(serverSocket);
93 
94     return a.exec();
95 }

客户端：

 1 // main.cpp
 2 #include <QCoreApplication>
 3 #include <iostream>
 4 #include <QDebug>
 5 #include <cstring>
 6 #include <WinSock2.h>
 7 #include <ws2tcpip.h>
 8 #include <QtNetwork>
 9 #pragma comment(lib, "ws2_32.lib")
10 #ifdef _WIN32
11     typedef int socklen_t;
12 #endif
13 
14 
15 int main(int argc, char *argv[])
16 {
17     QCoreApplication a(argc, argv);
18 
19 #ifdef _WIN32
20     WSADATA wsaData;
21     if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
22         std::cerr << "Failed to initialize WinSock" << std::endl;
23         return -1;
24     }
25 #endif
26 
27     int clientSocket = socket(AF_INET, SOCK_STREAM, 0);
28     if (clientSocket == -1)
29     {
30         std::cerr << "Error creating socket" << strerror(errno) << std::endl;
31         return -1;
32     }
33 
34     //准备地址结构
35     sockaddr_in serverAddress;
36     serverAddress.sin_family = AF_INET;
37     serverAddress.sin_port = htons(8888);
38     inet_pton(AF_INET, "127.0.0.1", &serverAddress.sin_addr);
39 
40     //连接到服务端
41     if (connect(clientSocket, (struct sockaddr*)&serverAddress, sizeof(serverAddress)) == -1)
42     {
43         std::cerr << "Error connecting to server" << std::endl;
44         closesocket(clientSocket);
45         return -1;
46     }
47 
48     std::cout << "Connected to server" << std::endl;
49 
50     //发送和接收数据
51     const char* message = "Hello server!";
52     send(clientSocket, message, strlen(message), 0);
53 
54     char buffer[1024];
55     memset(buffer, 0, sizeof(buffer));
56     recv(clientSocket, buffer, sizeof(buffer), 0);
57     std::cout << "Received from server: " << buffer << std::endl;
58 
59     //关闭套接字
60     closesocket(clientSocket);
61 
62     return a.exec();
63 }

注意：先运行服务器端，再运行客户端，可正常通信

运行效果：