C/C++实现http下载文件

一、使用MFC 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) {
                    //每次下载8K
                    int n = cFile->Read(p,(nLen 0)
				{
					InternetReadFile(handle2, Temp, MAXBLOCKSIZE - 1, &Number);
 
					fwrite(Temp, sizeof(char), Number, stream);
				}
				fclose(stream);
			}
 
			InternetCloseHandle(handle2);
			handle2 = NULL;
		}
		InternetCloseHandle(hSession);
		hSession = NULL;
	}
}

三、使用Windows提供的urlmon库

#include 
#include 
#include 
#include 
#include 
#include 
 
#pragma comment(lib, "urlmon.lib")
 
using namespace std;
 
BOOL FileExistsStatus(const CHAR* path)
{
	DWORD dwAttribute = GetFileAttributes(path);
	if (dwAttribute == 0XFFFFFFFF) return false; //0XFFFFFFFF表示文件不存在
	else return true;
}
 
BOOL DownloadFiles(const CHAR* url, const CHAR* downloadPath)
{
	if (URLDownloadToFile(NULL, url, downloadPath, 0, 0) == S_OK && FileExistsStatus(downloadPath)) return true;
	else return false;
}
 
int main(int argc, char* argv[])
{
	if (DownloadFiles(argv[1], argv[2])) printf("OK!\n");
	else printf("Error!\n");
	return 0;
}