用InternetOpen下载小文件 vc c++

#include "stdafx.h"
#include<windows.h>
#include<wininet.h>
#include<iostream.h>
#pragma comment(lib,"wininet.lib")
void  main()
{

    DWORD  byteread=0;
    char  buffer[100];
    memset(buffer,0,100);
    HINTERNET internetopen;

    internetopen=InternetOpen("Testing" ,INTERNET_OPEN_TYPE_PRECONFIG,NULL,NULL,0);
    if  (internetopen==NULL)
    {
        cout<<"Internet open failed!" <<endl;
        return ;
    }

    HINTERNET internetopenurl;
    internetopenurl=InternetOpenUrl(internetopen,"http://dt.163.com/images/news/0605/news02053101_5.jpg" ,NULL,0,INTERNET_FLAG_RELOAD,0);
    if  (internetopenurl==NULL)
    {
        cout<<"Internet open url failed!" <<endl;
        goto  there;
    }

    BOOL  hwrite;
    DWORD  written;
    HANDLE  createfile;
    createfile=CreateFile("c://sss.jpg" ,GENERIC_WRITE,0,0,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,0);
    if  (createfile==INVALID_HANDLE_VALUE)
    {
        cout<<"Create File failed!" <<endl;
        goto  next;
    }

    BOOL  internetreadfile;
    while (1)
    {
        internetreadfile=InternetReadFile(internetopenurl,buffer,sizeof (buffer),&byteread);
        if (byteread==0)
            break ;
        hwrite=WriteFile(createfile,buffer,sizeof (buffer),&written,NULL);
        if  (hwrite==0)
        {
            cout<<"Write to file failed!" <<endl;
            goto  here;
        }
    }

    cout<<"Finished downloading!" <<endl;

here:
    CloseHandle(createfile);
next:
    InternetCloseHandle(internetopenurl);
there:
    InternetCloseHandle(internetopen);

}