下了一个下载函数,有2个问题
发现 A:运行时候,对话框好象死掉一样不会动;
B:下载的文件过大时会程序会死掉;(就是不能支持大文件下载 >50M)
#include <Wininet.h>
连接器->输入 Wininet.lib
int CupdateDlg::InternetGetFile(CString szUrl, CString szFileName)
{
DWORD dwFlags;
InternetGetConnectedState(&dwFlags, 0);
CHAR strAgent[64];
HINTERNET hOpen;
if(!(dwFlags & INTERNET_CONNECTION_PROXY))
hOpen = InternetOpenA(strAgent, INTERNET_OPEN_TYPE_PRECONFIG_WITH_NO_AUTOPROXY, NULL, NULL, 0);
else
hOpen = InternetOpenA(strAgent, INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
if(!hOpen)
{
AfxMessageBox("Internet连接错误!");
return -1;
}
DWORD dwSize;
CHAR szHead[] = "Accept: */*\r\n\r\n";
VOID* szTemp[65536];
HINTERNET hConnect;
CFile file;
if ( !(hConnect = InternetOpenUrlA ( hOpen, szUrl, szHead,
lstrlenA (szHead), INTERNET_FLAG_DONT_CACHE | INTERNET_FLAG_PRAGMA_NOCACHE | INTERNET_FLAG_RELOAD, 0)))
{
AfxMessageBox("不能打开该URL!");
return -1;
}
if (file.Open(szFileName,CFile::modeWrite|CFile::modeCreate)==FALSE )
{
AfxMessageBox("不能打开本地的文件!");
return -1;
}
DWORD dwByteToRead = 0;
DWORD dwSizeOfRq = 4;
DWORD dwBytes = 0;
if (!HttpQueryInfo(hConnect, HTTP_QUERY_CONTENT_LENGTH | HTTP_QUERY_FLAG_NUMBER,
(LPVOID)&dwByteToRead, &dwSizeOfRq, NULL))
{
dwByteToRead = 0;
}
CString tempstring;
do
{
if (!InternetReadFile (hConnect, szTemp, 65536, &dwSize))
{
AfxMessageBox("读文件出错!");
file.Close();
return -1;
}
if (dwSize==0)
break;
else
file.Write(szTemp,dwSize);
dwBytes+=dwSize;
}while (TRUE);
file.Close();
InternetCloseHandle(hOpen);
return 0;
}