windows基于阿帕奇服务器，实现vc++文件下载功能

描述

windows基于阿帕奇服务器，实现vc++文件下载功能，要比上传功能简单一些，可以不需要php服务器，只要一个url路径就可以了。

下载函数代码

BOOL CDlgTest1::DownloadFileFromServer(const CString& strFileURLInServer, const CString & strFileLocalFullPath)
{
	ASSERT(strFileURLInServer != "");
	ASSERT(strFileLocalFullPath != "");
	CInternetSession session;
	CHttpConnection* pHttpConnection = NULL;
	CHttpFile* pHttpFile = NULL;
	CString strServer, strObject;
	INTERNET_PORT wPort;

	DWORD dwType;
	const int nTimeOut = 2000;
	session.SetOption(INTERNET_OPTION_CONNECT_TIMEOUT, nTimeOut); //重试之间的等待延时
	session.SetOption(INTERNET_OPTION_CONNECT_RETRIES, 1);   //重试次数
	char* pszBuffer = NULL; 

	try
	{
		AfxParseURL(strFileURLInServer, dwType, strServer, strObject, wPort);
		pHttpConnection = session.GetHttpConnection(strServer, wPort);
		pHttpFile = pHttpConnection->OpenRequest(CHttpConnection::HTTP_VERB_GET, strObject);
		if(pHttpFile->SendRequest() == FALSE)
			return false;
		
		DWORD dwStateCode;
		pHttpFile->QueryInfoStatusCode(dwStateCode);
		if(dwStateCode == HTTP_STATUS_OK)
		{
			HANDLE hFile = CreateFile(strFileLocalFullPath, GENERIC_WRITE,
							FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL,
							NULL);  //创建本地文件
			if(hFile == INVALID_HANDLE_VALUE)
			{
				pHttpFile->Close();
				pHttpConnection->Close();
				session.Close();
				return false;
			}
 
			char szInfoBuffer[1000];  //返回消息
			DWORD dwFileSize = 0;   //文件长度
			DWORD dwInfoBufferSize = sizeof(szInfoBuffer);
			BOOL bResult = FALSE;
			bResult = pHttpFile->QueryInfo(HTTP_QUERY_CONTENT_LENGTH,
							(void*)szInfoBuffer,&dwInfoBufferSize,NULL);

			dwFileSize = atoi(szInfoBuffer);
			const int BUFFER_LENGTH = 1024 * 10;
			pszBuffer = new char[BUFFER_LENGTH];  //读取文件的缓冲
			DWORD dwWrite, dwTotalWrite;
			dwWrite = dwTotalWrite = 0;
			UINT nRead = pHttpFile->Read(pszBuffer, BUFFER_LENGTH); //读取服务器上数据
			while(nRead > 0)
			{
				WriteFile(hFile, pszBuffer, nRead, &dwWrite, NULL);  //写到本地文件
				dwTotalWrite += dwWrite;
				nRead = pHttpFile->Read(pszBuffer, BUFFER_LENGTH);
			}

			delete[]pszBuffer;
			pszBuffer = NULL;
			CloseHandle(hFile);
		}
		else
		{
			delete[]pszBuffer;
			pszBuffer = NULL;
			if(pHttpFile != NULL)
			{
				pHttpFile->Close();
				delete pHttpFile;
				pHttpFile = NULL;
			}
			if(pHttpConnection != NULL)
			{
				pHttpConnection->Close();
				delete pHttpConnection;
				pHttpConnection = NULL;
			}
			session.Close();
			return false;
		}
	}
	catch(...)
	{
		delete[]pszBuffer;
		pszBuffer = NULL;
		if(pHttpFile != NULL)
		{
			pHttpFile->Close();
			delete pHttpFile;
			pHttpFile = NULL;
		}
		if(pHttpConnection != NULL)
		{
			pHttpConnection->Close();
			delete pHttpConnection;
			pHttpConnection = NULL;
		}
		session.Close();
		return false;
	}

	if(pHttpFile != NULL)
	{
		pHttpFile->Close();
		delete pHttpFile;
		pHttpFile = NULL;
	}

	if(pHttpConnection != NULL)
	{
		pHttpConnection->Close();
		delete pHttpConnection;
		pHttpConnection = NULL;
	}
	session.Close();
	return true;
}

代码分析

1.先调用AfxParseURL来获取URL参数。

2.连接对象

  pHttpConnection = session.GetHttpConnection(strServer, wPort);
  pHttpFile = pHttpConnection->OpenRequest(CHttpConnection::HTTP_VERB_GET, strObject);
3.创建本地文件

   HANDLE hFile = CreateFile(strFileLocalFullPath, GENERIC_WRITE,
       FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL,
       NULL); 

4.读取服务器上数据

   UINT nRead = pHttpFile->Read(pszBuffer, BUFFER_LENGTH); //读取服务器上数据
   while(nRead > 0)
   {
    WriteFile(hFile, pszBuffer, nRead, &dwWrite, NULL);  //写到本地文件
    dwTotalWrite += dwWrite;
    nRead = pHttpFile->Read(pszBuffer, BUFFER_LENGTH);
   }

 

测试可以从服务器上下载文件。

 

 转载请注明原创链接：http://blog.csdn.net/wujunokay/article/details/12838023