winsock 客户端套接字无效答案

【问题标题】：winsock client socket is invalidwinsock 客户端套接字无效
【发布时间】：2016-03-20 10:08:39
【问题描述】：

我想连接到一个特定的服务器，这个客户端代码使用winsock。但是创建的套接字是无效的，所以我得到“INVALID SOCKET”。

//Creating a socket for connecting to server
SOCKET hSocket;
hSocket = socket(AF_INET, SOCK_STREAM,0);
if (hSocket == INVALID_SOCKET)   //this is true!
{
    cout << "INVALID SOCKET" << endl;
}

/* This code assumes a socket has been created and its handle
is stored in a variable called hSocket */
sockaddr_in sockAddr;

sockAddr.sin_family = AF_INET;
sockAddr.sin_port = htons(54123);
sockAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");

// Connect to the server
if (connect(hSocket, (sockaddr*)(&sockAddr), sizeof(sockAddr)) != 0)
{
    cout << "ERROR while connecting" << endl;
}

【问题讨论】：

标签： c++ sockets client-server winsock

【解决方案1】：

我能想到的唯一问题是你没有WSAStartup()winsock。如果您没有，请检查https://msdn.microsoft.com/en-us/library/windows/desktop/ms742213%28v=vs.85%29.aspx。您也可以使用WSAGetLastError 来查看问题所在。

在代码顶部添加：

WSADATA wsaData;

//activate ws2_32.lib
int res = WSAStartup(MAKEWORD(2, 0), &wsaData);
if (res == 0){
    cout << "WSAStartup successful" << endl;
}
else {
    cout << "Error WSAStartup" << endl;
    return -201;
}

【讨论】：