C++怎么实现udp发送和接收

在C++中实现UDP发送和接收可以使用socket编程。下面是一个简单的示例代码：

发送UDP数据包：

#include <iostream>#include <string>#include <cstring>#include <unistd.h>#include <sys/socket.h>#include <netinet/in.h>int main() {    int sockfd;    struct sockaddr_in serverAddr;    // 创建UDP socket    sockfd = socket(AF_INET, SOCK_DGRAM, 0);    if (sockfd < 0) {        std::cerr << "Failed to create socket" << std::endl;        return -1;    }    // 设置服务器地址和端口    serverAddr.sin_family = AF_INET;    serverAddr.sin_port = htons(12345);    serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");    // 发送数据    std::string message = "Hello, UDP!";    sendto(sockfd, message.c_str(), message.length(), 0, (struct sockaddr*)&serverAddr, sizeof(serverAddr));    close(sockfd);    return 0;}

接收UDP数据包：

#include <iostream>#include <string>#include <cstring>#include <unistd.h>#include <sys/socket.h>#include <netinet/in.h>int main() {    int sockfd;    struct sockaddr_in serverAddr, clientAddr;    socklen_t addrLen = sizeof(clientAddr);    char buffer[1024];    // 创建UDP socket    sockfd = socket(AF_INET, SOCK_DGRAM, 0);    if (sockfd < 0) {        std::cerr << "Failed to create socket" << std::endl;        return -1;    }    // 设置服务器地址和端口    serverAddr.sin_family = AF_INET;    serverAddr.sin_port = htons(12345);    serverAddr.sin_addr.s_addr = INADDR_ANY;    // 绑定地址和端口    bind(sockfd, (struct sockaddr*)&serverAddr, sizeof(serverAddr));    // 接收数据    int bytesReceived = recvfrom(sockfd, buffer, 1024, 0, (struct sockaddr*)&clientAddr, &addrLen);    buffer[bytesReceived] = '\0';    std::cout << "Received: " << buffer << std::endl;    close(sockfd);    return 0;}

以上代码实现了一个简单的UDP发送和接收示例，可以根据实际需求进行进一步的扩展和优化。