#include <afx.h>

#include <afxinet.h>

#define RECVPACK_SIZE 2048

bool DownloadSaveFiles(char* url,char *strSaveFile) {//下载文件并保存为新文件名

    bool ret=false;

    CInternetSession Sess("lpload");

    Sess.SetOption(INTERNET_OPTION_CONNECT_TIMEOUT     , 2000); //2秒的连接超时

    Sess.SetOption(INTERNET_OPTION_SEND_TIMEOUT        , 2000); //2秒的发送超时

    Sess.SetOption(INTERNET_OPTION_RECEIVE_TIMEOUT     , 2000); //2秒的接收超时

    Sess.SetOption(INTERNET_OPTION_DATA_SEND_TIMEOUT   , 2000); //2秒的发送超时

    Sess.SetOption(INTERNET_OPTION_DATA_RECEIVE_TIMEOUT, 2000); //2秒的接收超时

    DWORD dwFlag = INTERNET_FLAG_TRANSFER_BINARY|INTERNET_FLAG_DONT_CACHE|INTERNET_FLAG_RELOAD ;

    CHttpFile* cFile   = NULL;

    char      *pBuf    = NULL;

    int        nBufLen = 0   ;

    do {

        try{

            cFile = (CHttpFile*)Sess.OpenURL(url,1,dwFlag);

            DWORD dwStatusCode;

            cFile->QueryInfoStatusCode(dwStatusCode);

            if (dwStatusCode == HTTP_STATUS_OK) {

                //查询文件长度

                DWORD nLen=0;

                cFile->QueryInfo(HTTP_QUERY_CONTENT_LENGTH, nLen);

                //CString strFilename = GetFileName(url,TRUE);

                nBufLen=nLen;

                if (nLen <= 0) break;//

                //分配接收数据缓存

                pBuf = (char*)malloc(nLen+8);

                ZeroMemory(pBuf,nLen+8);

                char *p=pBuf;

                while (nLen>0) {

                    //每次下载8K

                    int n = cFile->Read(p,(nLen<RECVPACK_SIZE)?nLen:RECVPACK_SIZE);

                    //接收完成退出循环

                    if (n <= 0) break;//

                    //接收缓存后移

                    p+= n ;

                    //剩余长度递减

                    nLen -= n ;

                }

                //如果未接收完中断退出

                if (nLen != 0) break;

                //接收成功保存到文件

                CFile file(strSaveFile, CFile::modeCreate | CFile::modeWrite);

                file.Write(pBuf,nBufLen);

                file.Close();

                ret = true;

            }

        } catch(...) {

            break;//

        }

    } while(0);

    //释放缓存

    if (pBuf) {

        free(pBuf);

        pBuf=NULL;

        nBufLen = 0 ;

    }

    //关闭下载连接

    if (cFile) {

        cFile->Close();

        Sess.Close();

        delete cFile;

    }

    return ret;

}

int main() {

    DownloadSaveFiles("http://www.nirsoft.net/utils/nircmd.zip","d:\\cppdld_nircmd.zip");

    return 0;

}