获取本机IP

// ConsoleApplication12.cpp : This file contains the 'main' function. Program execution begins and ends there.
//
#include <winsock2.h>
#include <windows.h>
#include <WS2tcpip.h>
#include <IPTypes.h>
#include <iphlpapi.h>
#include <iostream>

#pragma comment(lib, "ws2_32.lib")
#pragma comment(lib, "IPHLPAPI.lib")

using namespace std;



void get_local_ip()
{
    ULONG rCode = 0;
    ULONG Length = sizeof(IP_ADAPTER_INFO);
    std::string IpAddr;

    PIP_ADAPTER_INFO pIpAdapterInfo = new IP_ADAPTER_INFO();

    rCode = GetAdaptersInfo(pIpAdapterInfo, &Length);

    if (ERROR_BUFFER_OVERFLOW == rCode) {
        //重新申请内存空间用来存储所有网卡信息        
        delete pIpAdapterInfo;
        pIpAdapterInfo = (PIP_ADAPTER_INFO)new BYTE[Length];
        rCode = GetAdaptersInfo(pIpAdapterInfo, &Length);
    }
    if (rCode == ERROR_SUCCESS) {
        //返回第一张网卡的第一个IP地址
        for (UINT i = 0; i < 16; i++) {
            if (!pIpAdapterInfo->IpAddressList.IpAddress.String[i])
                break;

            IpAddr += pIpAdapterInfo->IpAddressList.IpAddress.String[i];

        }
    }
    if (pIpAdapterInfo) {
        delete pIpAdapterInfo;
    }
    cout << IpAddr.c_str() << endl;
    //return IpAddr;
}


int main()
{
    get_local_ip();
    //cout << ip.c_str() << endl;
    std::cout << "Hello World!
" << endl;
    getchar();
}