C/C++实现FTP文件上传下载的示例详解

HINTERNET InternetOpen(
  LPCWSTR lpszAgent,  // 用户代理字符串，标识应用程序的名称
  DWORD   dwAccessType, // 访问类型，可以是 DIRECT、PRECONFIG 或 PROXY
  LPCWSTR lpszProxyName, // 代理服务器名称
  LPCWSTR lpszProxyBypass, // 代理服务器的绕过列表
  DWORD   dwFlags // 一些标志，例如INTERNET_FLAG_ASYNC（异步操作）
);

HINTERNET InternetConnect(
  HINTERNET     hInternet,       // InternetOpen 返回的句柄
  LPCWSTR       lpszServerName,  // 服务器的主机名
  INTERNET_PORT nServerPort,      // 服务器的端口号
  LPCWSTR       lpszUsername,    // 用户名
  LPCWSTR       lpszPassword,    // 密码
  DWORD         dwService,       // 服务类型，例如 INTERNET_SERVICE_HTTP
  DWORD         dwFlags,         // 一些标志，例如 INTERNET_FLAG_RELOAD
  DWORD_PTR     dwContext        // 应用程序定义的上下文
);

BOOL InternetWriteFile(
  HINTERNET hFile,           // 由 InternetOpenUrl 或 HttpOpenRequest 返回的文件句柄
  LPCVOID   lpBuffer,        // 指向包含要写入的数据的缓冲区的指针
  DWORD     dwNumberOfBytesToWrite,  // 要写入的字节数
  LPDWORD   lpdwNumberOfBytesWritten  // 指向接收实际写入的字节数的指针
);

BOOL InternetReadFile(
  HINTERNET hFile,         // 由 InternetOpenUrl 或 HttpOpenRequest 返回的文件句柄
  LPVOID    lpBuffer,      // 指向接收数据的缓冲区的指针
  DWORD     dwNumberOfBytesToRead,  // 要读取的字节数
  LPDWORD   lpdwNumberOfBytesRead  // 指向接收实际读取的字节数的指针
);

#include <iostream>
#include <Windows.h>
#include <WinInet.h>

#pragma comment(lib, "WinInet.lib")

// 保存文件到本地
BOOL FtpSaveToFile(char *pszFileName, BYTE *pData, DWORD dwDataSize)
{
	// 创建空文件
	HANDLE hFile = CreateFile(pszFileName, GENERIC_READ | GENERIC_WRITE,
		FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, CREATE_ALWAYS,
		FILE_ATTRIBUTE_ARCHIVE, NULL);
	if (INVALID_HANDLE_VALUE == hFile)
		return FALSE;

	DWORD dwRet = 0;

	// 写出数据到文件
	WriteFile(hFile, pData, dwDataSize, &dwRet, NULL);

	// 关闭句柄
	CloseHandle(hFile);
	return TRUE;
}

BOOL FTPDownload(char *szHostName, char *szUserName, char *szPassword, char *szUrlPath, char *SavePath)
{
	HINTERNET hInternet, hConnect, hFTPFile = NULL;
	BYTE *pDownloadData = NULL;
	DWORD dwDownloadDataSize = 0;
	DWORD dwBufferSize = 4096;
	BYTE *pBuf = NULL;
	DWORD dwBytesReturn = 0;
	DWORD dwOffset = 0;
	BOOL bRet = FALSE;

	// 建立会话并打开FTP操作
	hInternet = InternetOpen("WinInet Ftp", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
	hConnect = InternetConnect(hInternet, szHostName, INTERNET_INVALID_PORT_NUMBER,szUserName, szPassword, INTERNET_SERVICE_FTP, INTERNET_FLAG_PASSIVE, 0);
	hFTPFile = FtpOpenFile(hConnect, szUrlPath, GENERIC_READ, FTP_TRANSFER_TYPE_BINARY | INTERNET_FLAG_RELOAD, NULL);
	
	// 获取文件大小并初始化缓冲区
	dwDownloadDataSize = FtpGetFileSize(hFTPFile, NULL);
	pDownloadData = new BYTE[dwDownloadDataSize];
	RtlZeroMemory(pDownloadData, dwDownloadDataSize);
	pBuf = new BYTE[dwBufferSize];
	RtlZeroMemory(pBuf, dwBufferSize);
	
	// 循环接收数据
	do
	{
		// 读取数据
		bRet = InternetReadFile(hFTPFile, pBuf, dwBufferSize, &dwBytesReturn);
		if (FALSE == bRet)
			break;
		
		// 将读取到的数据追加到内存
		RtlCopyMemory((pDownloadData + dwOffset), pBuf, dwBytesReturn);
		dwOffset = dwOffset + dwBytesReturn;
	} while (dwDownloadDataSize > dwOffset);

	// 保存变量中的数据为文件
	FtpSaveToFile(SavePath, pDownloadData, dwDownloadDataSize);
	
	// 释放内存
	delete[]pDownloadData;
	pDownloadData = NULL;
	return TRUE;
}

int main(int argc, char * argv[])
{
	BOOL bRET = FTPDownload("127.0.0.1", "admin", "admin", "/lyshark.jpg", "d://newtest/lyshark.jpg");
	if (bRET == TRUE)
	{
		printf("已下载文件 \n");
	}
	else
	{
		printf("下载失败 \n");
	}

	system("pause");
	return 0;
}

#include <iostream>
#include <Windows.h>
#include <WinInet.h>

#pragma comment(lib, "WinInet.lib")

// 实现文件上传操作
BOOL FTPUpload(char *szHostName, char *szUserName, char *szPassword, char *szUrlPath, char *FilePath)
{
  HINTERNET hInternet, hConnect, hFTPFile = NULL;
  DWORD dwBytesReturn = 0;
  DWORD UploadDataSize = 0;
  BYTE *pUploadData = NULL;
  DWORD dwRet, bRet = 0;

  // 建立会话并打开FTP操作
  hInternet = InternetOpen("WinInet Ftp", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
  hConnect = InternetConnect(hInternet, szHostName, INTERNET_INVALID_PORT_NUMBER, szUserName, szPassword, 
    INTERNET_SERVICE_FTP, INTERNET_FLAG_PASSIVE, 0);
  hFTPFile = FtpOpenFile(hConnect, szUrlPath, GENERIC_WRITE, FTP_TRANSFER_TYPE_BINARY | INTERNET_FLAG_RELOAD, NULL);

  // 打开文件
  HANDLE hFile = CreateFile(FilePath, GENERIC_READ | GENERIC_WRITE,FILE_SHARE_READ | 
    FILE_SHARE_WRITE, NULL, OPEN_EXISTING,FILE_ATTRIBUTE_ARCHIVE, NULL);
  if (INVALID_HANDLE_VALUE == hFile)
    return FALSE;

  // 获取文件大小
  UploadDataSize = GetFileSize(hFile, NULL);
  pUploadData = new BYTE[UploadDataSize];
  // 读取文件到缓冲区
  ReadFile(hFile, pUploadData, UploadDataSize, &dwRet, NULL);
  UploadDataSize = dwRet;

  // 开始上传数据
  bRet = InternetWriteFile(hFTPFile, pUploadData, UploadDataSize, &dwBytesReturn);
  if (FALSE == bRet)
  {
    delete[]pUploadData;
    return FALSE;
  }
  delete[]pUploadData;
  return TRUE;
}

int main(int argc, char * argv[])
{
	BOOL bRET = FTPUpload("127.0.0.1", "admin", "admin", "/abc.exe", "c://nc.exe");
	if (bRET == TRUE)
	{
		printf("已上传文件 \n");
	}
	else
	{
		printf("上传失败 \n");
	}

	system("pause");
	return 0;
}