vc 保存http服务器文件到本地-优快云博客

本文介绍了一个使用Wininet.h库中的函数实现从指定URL获取数据并保存到本地文件的方法。该方法首先通过InternetOpen和InternetOpenUrl函数建立连接，然后使用HttpQueryInfo获取文件大小，并利用InternetReadFile读取数据。

#include "Wininet.h"

#pragma comment(lib, "Wininet.lib")

BOOL GetDataFromUrl(LPCTSTR pszUrl, LPBYTE lpData, DWORD& dwDataSize, DWORD& dwBytesRead)
{
CString str;
HINTERNET hSession = ::InternetOpen(_T("YourSectionName") , INTERNET_OPEN_TYPE_PRECONFIG , NULL , NULL , 0);
if(hSession == NULL)
return FALSE;

HINTERNET hHttpFile = ::InternetOpenUrl(hSession , pszUrl , NULL , 0 , 0 , 0);
if(hHttpFile == NULL)
{
::InternetCloseHandle(hSession);
return FALSE;
}

TCHAR szSizeBuffer [MAX_PATH];
DWORD dwLengthSizeBuffer = sizeof(szSizeBuffer);
BOOL bRetun = FALSE;
if(::HttpQueryInfo(hHttpFile, HTTP_QUERY_CONTENT_LENGTH, szSizeBuffer, &dwLengthSizeBuffer, NULL))
{
DWORD dwFileSize = _ttol(szSizeBuffer);
dwBytesRead = 0;
if(dwDataSize < dwFileSize)
{
dwDataSize = dwFileSize;
}
else if(::InternetReadFile(hHttpFile , lpData , dwFileSize , &dwBytesRead))
{
bRetun=TRUE;
}
}

::InternetCloseHandle(hHttpFile);
::InternetCloseHandle(hSession);
return bRetun;

}

BOOL SaveHttpFile(LPCTSTR pszUrl, LPCTSTR lpszFile)

{
DWORD dataSize = 0;
DWORD dwByte = 0;
GetDataFromUrl(pszUrl, NULL, dataSize, dwByte);
if(dataSize == 0)
return FALSE;

CFile file;
if(!file.Open(lpszFile, CFile::modeCreate|CFile::modeWrite))
return FALSE;

LPBYTE lpData = new BYTE[dataSize];
memset(lpData, 0, dataSize);
BOOL bRet = GetDataFromUrl(pszUrl, lpData, dataSize, dwByte);

if(bRet)
file.Write(lpData, dwByte);

delete []lpData;
return bRet;
}