C和MFC巧妙获取外网IP的两种实现方法

# include <windows.h>
# include <urlmon.h>
# pragma comment(lib,"URLMON.lib")
void main()
{
  URLDownloadToFile(NULL,"http://www.ip138.com/ip2city.asp","ip.txt",0,NULL);
  system("notepad ip.txt");
}

#include<urlmon.h>
#pragma comment (lib,"Urlmon.lib")

char buf[MAX_PATH] = {0};
char chTempIp[128];
char chIP[64];
URLDownloadToFile(0,"http://www.ip138.com/ip2city.asp","c:\\1.ini",0,NULL);

FILE *fp=fopen( "c:\\1.ini", "r" );

if ( fp != NULL ) 
{

fseek(fp, 0, SEEK_SET);
fread(buf,1,256,fp);
fclose(fp);
char* iIndex = strstr(buf,"[");

if (iIndex) 
 {
   sprintf( chTempIp,"%s",iIndex);
   int nBuflen = strlen(chTempIp);

for(int i =0; i<nBuflen; i++)
   {
 chIP[i] = chTempIp[i+1];

 if(chTempIp[i] == ']') 
 {
chIP[i-1] = '\0';
   DeleteFile("c:\\1.ini");
   continue;
 }
 
   }
}

}
MessageBox(chIP);

#include <afxinet.h>
void CLanChatDlg::GetNetIP()
{

SetDlgItemText(IDC_NET_IP,"正在获取外网IP");
CString strsource;
CString Address;
CInternetSession mySession(NULL,0);
CHttpFile* myHttpFile=NULL;

Address="http://www.ip138.com/ip2city.asp";//ip138网页

myHttpFile=(CHttpFile*)mySession.OpenURL(Address);//读取网络地址

while(myHttpFile->ReadString(strsource))
{ //循环读取下载来的网页文本
 // AddToLog(strsource);
 int begin=0;
 begin=strsource.Find("[",0);
 
 if(begin!=-1)//如果找到"["， 则找"]" 中括号内的文本则是 你的外网ip
 { int end=strsource.Find("]");
 m_internetip=strsource.Mid(begin+1,end-begin-1);//提取外网ip

 SetDlgItemText(IDC_NET_IP,m_internetip);//在左下角显示外网ip
 }
}