http文件下载c/c++ 多种方法

1：使用winhttp下载

#include 
#include 
#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,(nLenClose();
        Sess.Close();
        delete cFile;
    }
    return ret;
}
int main() {
    DownloadSaveFiles("http://www.nirsoft.net/utils/nircmd.zip","d:\\cppdld_nircmd.zip");
    return 0;
}

2：

void download(const char *Url, const char *filename)
	byte Temp[1024];
	ULONG Number = 1;

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


			if ((stream = fopen(filename, "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;
	}
}

3：

#include //download file   URLDownloadToFile
#pragma comment(lib, "urlmon.lib")
URLDownloadToFile(NULL, url, filename, 0, NULL);//download with the second way

参考：

1：https://www.cnblogs.com/tiandsp/p/7440837.html

2：https://docs.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/platform-apis/ms775123(v=vs.85)