c++电子邮件接收程序 源码下载（基于POP3协议）

【核心代码】

// MailClientDlg.cpp : implementation file
//

#include "stdafx.h"
#include "MailClient.h"
#include "MailClientDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
	CAboutDlg();

// Dialog Data
	//{{AFX_DATA(CAboutDlg)
	enum { IDD = IDD_ABOUTBOX };
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CAboutDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
	//}}AFX_VIRTUAL

// Implementation
protected:
	//{{AFX_MSG(CAboutDlg)
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
	//{{AFX_DATA_INIT(CAboutDlg)
	//}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAboutDlg)
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
	//{{AFX_MSG_MAP(CAboutDlg)
		// No message handlers
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMailClientDlg dialog

CMailClientDlg::CMailClientDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CMailClientDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CMailClientDlg)
	m_Address="pop3.126.com";
	m_Login = _T("");
	m_Mail = _T("");
	m_Password = _T("");
	m_Account = _T("");
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CMailClientDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CMailClientDlg)
	DDX_Text(pDX, IDC_EDIT_ADDRESS, m_Address);
	DDX_Text(pDX, IDC_EDIT_LOGIN, m_Login);
	DDX_Text(pDX, IDC_EDIT_MAIL, m_Mail);
	DDX_Text(pDX, IDC_EDIT_PASSWORD, m_Password);
	DDX_Text(pDX, IDC_EDIT_ACCOUNT, m_Account);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CMailClientDlg, CDialog)
	//{{AFX_MSG_MAP(CMailClientDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_CONNECT, OnConnect)
	ON_BN_CLICKED(IDC_RECEIVE, OnReceive)
	ON_BN_CLICKED(IDC_QUIT, OnQuit)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMailClientDlg message handlers

BOOL CMailClientDlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	// Add "About..." menu item to system menu.

	// IDM_ABOUTBOX must be in the system command range.
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != NULL)
	{
		CString strAboutMenu;
		strAboutMenu.LoadString(IDS_ABOUTBOX);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// Set the icon for this dialog.  The framework does this automatically
	//  when the application's main window is not a dialog
	SetIcon(m_hIcon, TRUE);			// Set big icon
	SetIcon(m_hIcon, FALSE);		// Set small icon
	
	// TODO: Add extra initialization here
	
	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CMailClientDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialog::OnSysCommand(nID, lParam);
	}
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CMailClientDlg::OnPaint() 
{
	if (IsIconic())
	{
		CPaintDC dc(this); // device context for painting

		SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

		// Center icon in client rectangle
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon   1) / 2;
		int y = (rect.Height() - cyIcon   1) / 2;

		// Draw the icon
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{
		CDialog::OnPaint();
	}
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CMailClientDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

void CMailClientDlg::OnConnect() 
{
	// TODO: Add your control notification handler code here
	WSADATA WSAData;
	if (WSAStartup(MAKEWORD(2,2),&WSAData)!=0)
	{
       MessageBox("初始化Winsock失败！");
	   return;
	}

	Socket=socket(AF_INET,SOCK_STREAM,0);
	if (Socket==INVALID_SOCKET)
	{
      MessageBox("创建Socket失败！");
	  WSACleanup();
	  return;
	}

	UpdateData(TRUE);

	int IpAddress;
	IpAddress=inet_addr(m_Address);
	if (IpAddress==INADDR_NONE)
	{
        hostent* pHostent=gethostbyname(m_Address);
	if (pHostent)
		IpAddress=(*(in_addr*)pHostent->h_addr).s_addr;
	}

	sockaddr_in serveraddr;
	memset(&serveraddr,0,sizeof(serveraddr));
	serveraddr.sin_family=AF_INET;
	serveraddr.sin_port=htons(110);
    serveraddr.sin_addr.s_addr=IpAddress;


	int nConnect;
	nConnect=connect(Socket, (sockaddr*)&serveraddr,sizeof(sockaddr));
	if (nConnect==SOCKET_ERROR)
	{
       MessageBox("连接建立失败！");
	   closesocket(Socket);
	   WSACleanup();
	   return;
	}

	m_Login ="Client: Connect to ";
	m_Login =m_Address;
	m_Login ="...\r\n";
	if (!RecvRespond())
		return;
	else
	{
       if (RespondStatus==true)
	   {
          m_Login ="Server: ";
		  m_Login =Respond;
	   }
	   else
	   {
         MessageBox("连接响应错误！");
		 closesocket(Socket);
		 WSACleanup();
		 return;
	   }
	}

	memset(Command,0,MAX_SIZE);//合成USER命令
	memcpy(Command,"USER ",strlen("USER "));
	memcpy(Command strlen("USER "),m_Account,strlen(m_Account));
	memcpy(Command strlen("USER ") strlen(m_Account),"\r\n",2);
	if (!SendCommand())//发送USER命令
		return;
	m_Login ="Client: ";
	m_Login =Command;
	if (!RecvRespond())
		return;
	else
	{
		if (RespondStatus==true)//判断USER响应状态
        {
           m_Login ="Server: ";
		   m_Login =Respond;
		}
		else
		{
           MessageBox("USER响应错误！");
		   closesocket(Socket);
		   WSACleanup();
		   return;
		}
	}

	memset(Command,0,MAX_SIZE);//合成PASS命令
	memcpy(Command,"PASS ",strlen("PASS "));
	memcpy(Command strlen("PASS "),m_Password,strlen(m_Password));
	memcpy(Command strlen("PASS ") strlen(m_Password),"\r\n",2);
	if (!SendCommand())
	  return;
	m_Login ="Client: PASS ******\r\n";
	if (!RecvRespond())
		return;
	else
	{
       if (RespondStatus==true)//判断PASS响应状态
	   {
          m_Login ="Server: ";
		  m_Login =Respond;
	   }
	   else
	   {
		   MessageBox("PASS响应错误！");
		   closesocket(Socket);
		   WSACleanup();
		   return;
	   }
	}

	UpdateData(FALSE);

}

void CMailClientDlg::OnReceive() 
{
	// TODO: Add your control notification handler code here
	memset(Command,0,MAX_SIZE);//合成STAT命令
	memcpy(Command,"STAT",strlen("STAT"));
    memcpy(Command strlen("STAT"),"\r\n",2);
	if (!SendCommand())
		return;
	m_Login ="Client: ";
	m_Login =Command;
	if (!RecvRespond())
		return;
	else
	{
       if (RespondStatus==true)//判断STAT响应状态
	   {
           m_Login ="Server: ";
		   m_Login =Respond;
	   }
	   else
	   {
         MessageBox("STAT响应错误！");
		 closesocket(Socket);
		 WSACleanup();
		 return;
	   }
	}

	char* pLast=strtok(Respond," ");
	pLast=strtok(NULL," ");
	int len=strlen(pLast);

	memset(Command,0,MAX_SIZE);//合成RETR命令,接收最新的邮件
	memcpy(Command,"RETR ",strlen("RETR "));
	//memcpy(Command strlen("RETR "),"1\r\n",3);
	memcpy(Command strlen("RETR "),pLast,len);
	memcpy(Command strlen("RETR ") len,"\r\n",2);
	if (!SendCommand())
		return;
	m_Login ="Client: ";
	m_Login =Command;
	if (!RecvRespond())
		return;
	else
	{
       if (RespondStatus==true)//判断RETR响应状态
	   {
          m_Login ="Server: ";
		  m_Login =Respond;
	   }
	   else
	   {
         MessageBox("RETR响应错误！");
		 closesocket(Socket);
		 WSACleanup();
		 return;
	   }  
	}

	while (true)
	{
       char MailBuf[MAX_SIZE];
	   memset(MailBuf,0,MAX_SIZE);
	   int nRecv;
	   nRecv=recv(Socket,MailBuf,MAX_SIZE,0);
	   if (nRecv==SOCKET_ERROR)//读取邮件信息
	   {
         MessageBox("RETR接收错误！");
		 closesocket(Socket);
		 WSACleanup();
		 return;
	   }

	   m_Mail =MailBuf;//显示邮件信息
	   if (strstr(MailBuf,"\r\n.\r\n"))
		   break;
	}

	UpdateData(FALSE);
}

void CMailClientDlg::OnQuit() 
{
	// TODO: Add your control notification handler code here
    memset(Command,0,MAX_SIZE);
	memcpy(Command,"QUIT",strlen("QUIT"));
	memcpy(Command strlen("QUIT"),"\r\n",2);
	if (!SendCommand())
		return;
	m_Login ="Client: ";
	m_Login =Command;
	if (!RecvRespond())
		return;
	else
	{
      if (RespondStatus==true)
	  {
        m_Login ="Server: ";
		  m_Login =Respond;
		  m_Mail="";
	  }
	  else
	  {
        MessageBox("QUIT响应错误！");
		closesocket(Socket);
		WSACleanup();
		return;       
	  }
	}

	UpdateData(FALSE);
	closesocket(Socket);
	WSACleanup();
}	

bool CMailClientDlg::RecvRespond()
{

	int nRecv;
	memset(Respond,0,MAX_SIZE);
	nRecv=recv(Socket,Respond,MAX_SIZE,0);
	if (nRecv==SOCKET_ERROR)
	{
       MessageBox("Socket接收失败！");
	   closesocket(Socket);
	   WSACleanup();
	   return false;
	}

	if (memcmp(Respond," OK",3)==0)
		RespondStatus=true;
	else
		RespondStatus=false;

	return true;
}

bool CMailClientDlg::SendCommand()
{
  int nSend;
  nSend=send(Socket,Command,strlen(Command),0);
  if (nSend==SOCKET_ERROR)
  {
     MessageBox("Socket发送失败！");
	 closesocket(Socket);
	 WSACleanup();
	 return false;
  }

  return true;
}