基于qt的网络编程
在QT中编写网络发报端/客户端，时build时出现
error: undefined reference to `_imp__WSAStartup@8’等，很多网络类似的错误
等大约10条error，原因是socket库的编译链接问题。
错误原因：因为没有联接socket库ws2_32.lib。因此要链接该库
总结：所有运用到WinSock2的程序在编译连接时都要用的该库
解决办法：
在项目的pro文件中添加：
LIBS += -lpthread libwsock32 libws2_32
Windows下UDPServer
#include<winsock2.h>
#include<stdio.h>
#include<string.h>
#include<iostream>
using namespace std;
#pragma comment(lib,"ws2_32.lib")
#define BUFFER_SIZE 1024
int main()
{
WSADATA WSAData;
char receBuf[BUFFER_SIZE];
char Response[] = "";
if (WSAStartup(MAKEWORD(2, 2), &WSAData) != 0) {
printf("初始化失败");
exit(1);
}
SOCKET sockServer = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (sockServer == INVALID_SOCKET) {
printf("Failed socket() \n");
return 0;
}
SOCKADDR_IN addr_Server; //服务器的地址等信息
addr_Server.sin_family = AF_INET;
addr_Server.sin_port = htons(4567);//端口号设置为4567
addr_Server.sin_addr.S_un.S_addr = INADDR_ANY;
if (bind(sockServer, (SOCKADDR*)&addr_Server, sizeof(addr_Server)) == SOCKET_ERROR) {
//服务器与本地地址绑定
printf("Failed socket() %d \n", WSAGetLastError());
return 0;
}
SOCKADDR_IN addr_Clt;
int fromlen = sizeof(SOCKADDR);
while (true) {
int last = recvfrom(sockServer, receBuf, 1024, 0, (SOCKADDR*)&addr_Clt, &fromlen);
if (last>0) {
//判断接收到的数据是否为空
receBuf[last] = '\0';//给字符数组加一个'\0'，表示结束了。不然输出有乱码
if (strcmp(receBuf, "bye") == 0) {
cout << " 客户端关闭..." << endl;
closesocket(sockServer);
return 0;
} else {
printf("接收到数据（%s）：%s\n", inet_ntoa(addr_Clt.sin_addr), receBuf);
}
}
cout << "回复客户端消息:";
cin >> Response; //给客户端回复消息
sendto(sockServer, Response, strlen(Response), 0, (SOCKADDR*)&addr_Clt, sizeof(SOCKADDR));
}
closesocket(sockServer);
WSACleanup();
return 0;
}
Windows下UDPClient
#include<winsock2.h>
#include<stdio.h>
#include<string.h>
#include<iostream>
using namespace std;
#pragma comment(lib,"ws2_32.lib")
# define BUFFER_SIZE 1024 //缓冲区大小
int main()
{
SOCKET sock_Client; //客户端用于通信的Socket
WSADATA WSAData;
char receBuf[BUFFER_SIZE]; //发送数据的缓冲区
char sendBuf[BUFFER_SIZE]; //接受数据的缓冲区
if (WSAStartup(MAKEWORD(2, 2), &WSAData) != 0) {
printf("初始化失败!");
return -1;
}
//初始化
sock_Client = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);//创建客户端用于通信的Socket
SOCKADDR_IN addr_server; //服务器的地址数据结构
addr_server.sin_family = AF_INET;
addr_server.sin_port = htons(4567);//端口号为4567
addr_server.sin_addr.S_un.S_addr = inet_addr("127.0.0.1"); //127.0.0.1为本电脑IP地址
SOCKADDR_IN sock;
int len = sizeof(sock);
while (true) {
cout << "请输入要传送的数据:";
cin >> sendBuf;
sendto(sock_Client, sendBuf, strlen(sendBuf), 0, (SOCKADDR*)&addr_server, sizeof(SOCKADDR));
//int last=recv(sock_Client, receBuf, strlen(receBuf), 0); // (调用recv和recvfrom都可以)
int last = recvfrom(sock_Client, receBuf, strlen(receBuf), 0, (SOCKADDR*)&sock, &len);
if (last>0) {
receBuf[last] = '\0'; //给字符数组加一个'\0'，表示结束了。不然输出有乱码
if (strcmp(receBuf, "bye") == 0) {
cout << "服务器关闭" << endl;//当服务器发来bye时，关闭socket
closesocket(sock_Client);
break;
} else {
printf("接收到数据：%s\n", receBuf);
}
}
}
closesocket(sock_Client);
WSACleanup();
return 0;
}