c++编程 实现下载文件

下载文件要用到操作系统的API函数，下面是一个WINDOWS系统中的实现：

//---------------------------------------------------------------------------

#include
#include
#include
#define MAXBLOCKSIZE 1024
#pragma comment( lib, "wininet.lib" ) ;

void download(const char *Url,const char *save_as)/*将Url指向的地址的文件下载到save_as指向的本地文件*/
{
byte Temp[MAXBLOCKSIZE];
ULONG Number = 1;

FILE *stream;
HINTERNET hSession = InternetOpen((LPCWSTR)"RookIE/1.0", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
if (hSession != NULL)
{
HINTERNET handle2 = InternetOpenUrl(hSession, (LPCWSTR)Url, NULL, 0, INTERNET_FLAG_DONT_CACHE, 0);
if (handle2 != NULL)
{

if( (stream = fopen( save_as, "wb" )) != NULL )
{
while (Number > 0)
{
InternetReadFile(handle2, Temp, MAXBLOCKSIZE - 1, &Number);

fwrite(Temp, sizeof (char), Number , stream);
}
fclose( stream );
}

InternetCloseHandle(handle2);
handle2 = NULL;
}
InternetCloseHandle(hSession);
hSession = NULL;
}
}

int main(int argc, char* argv[]){

download("http://www.baidu.com/","c:\\index.html");/*调用示例，下载百度的首页到c:\index.html文件*/
return 0;
}

//---------------------------------------------------------------------------