www.pudn.com > despop3client_demo.zip > Pop3Client.cs

using System; 
using System.Collections; 
using System.IO; 
using System.Net; 
using System.Net.Sockets; 
using System.Threading; 
using System.Text; 
using System.Text.RegularExpressions; 
using System.Diagnostics; 
 
namespace Pop3 
{ 
	public class Pop3Client 
	{ 
		private Pop3Credential m_credential; 
 
		private const int m_pop3port = 110; 
		private const int MAX_BUFFER_READ_SIZE = 256; 
		 
		private long m_inboxPosition = 0; 
		private long m_directPosition = -1; 
 
		private Socket m_socket = null; 
  
		private Pop3Message m_pop3Message = null; 
 
		public Pop3Credential UserDetails 
		{ 
			set { m_credential = value; } 
			get { return m_credential; } 
		} 
 
		public string From 
		{ 
			get { return m_pop3Message.From; } 
		} 
 
		public string To 
		{ 
			get { return m_pop3Message.To; } 
		} 
 
		public string Subject 
		{ 
			get { return m_pop3Message.Subject; } 
		} 
 
		public string Body 
		{ 
			get { return m_pop3Message.Body; } 
		} 
 
		public IEnumerator MultipartEnumerator 
		{ 
			get { return m_pop3Message.MultipartEnumerator; } 
		} 
 
		public bool IsMultipart 
		{ 
			get { return m_pop3Message.IsMultipart; } 
		} 
 
 
		public Pop3Client(string user, string pass, string server) 
		{ 
			m_credential = new Pop3Credential(user,pass,server); 
		} 
 
		private Socket GetClientSocket() 
		{ 
			Socket s = null; 
			 
			try 
			{ 
				IPHostEntry hostEntry = null; 
         
				// Get host related information. 
				hostEntry = Dns.Resolve(m_credential.Server); 
 
				// Loop through the AddressList to obtain the supported  
				// AddressFamily. This is to avoid an exception that  
				// occurs when the host IP Address is not compatible  
				// with the address family  
				// (typical in the IPv6 case). 
				 
				foreach(IPAddress address in hostEntry.AddressList) 
				{ 
					IPEndPoint ipe = new IPEndPoint(address, m_pop3port); 
				 
					Socket tempSocket =  
						new Socket(ipe.AddressFamily,  
						SocketType.Stream, ProtocolType.Tcp); 
 
					tempSocket.Connect(ipe); 
 
					if(tempSocket.Connected) 
					{ 
						// we have a connection. 
						// return this socket ... 
						s = tempSocket; 
						break; 
					} 
					else 
					{ 
						continue; 
					} 
				} 
			} 
			catch(Exception e) 
			{ 
				throw new Pop3ConnectException(e.ToString()); 
			} 
 
			// throw exception if can't connect ... 
			if(s == null) 
			{ 
				throw new Pop3ConnectException("Error : connecting to " 
					+m_credential.Server); 
			} 
			 
			return s; 
		} 
 
		//send the data to server 
		private void Send(String data)  
		{ 
			if(m_socket == null) 
			{ 
				throw new Pop3MessageException("Pop3 connection is closed"); 
			} 
 
			try 
			{ 
				// Convert the string data to byte data  
				// using ASCII encoding. 
				 
				byte[] byteData = Encoding.ASCII.GetBytes(data+"\r\n"); 
				 
				// Begin sending the data to the remote device. 
				m_socket.Send(byteData); 
			} 
			catch(Exception e) 
			{ 
				throw new Pop3SendException(e.ToString()); 
			} 
		} 
 
		private string GetPop3String() 
		{ 
			if(m_socket == null) 
			{ 
				throw new  
					Pop3MessageException("Connection to POP3 server is closed"); 
			} 
 
			byte[] buffer = new byte[MAX_BUFFER_READ_SIZE]; 
			string line = null; 
 
			try 
			{ 
				int byteCount =  
					m_socket.Receive(buffer,buffer.Length,0); 
 
				line =  
					Encoding.ASCII.GetString(buffer, 0, byteCount); 
			} 
			catch(Exception e) 
			{ 
				throw new Pop3ReceiveException(e.ToString()); 
			} 
 
			return line; 
		} 
 
		private void LoginToInbox() 
		{ 
			string returned; 
 
			// send username ... 
			Send("user "+m_credential.User); 
		 
			// get response ... 
			returned = GetPop3String(); 
 
			if( !returned.Substring(0,3).Equals("+OK") ) 
			{ 
				throw new Pop3LoginException("login not excepted"); 
			} 
 
			// send password ... 
			Send("pass "+m_credential.Pass); 
 
			// get response ... 
			returned = GetPop3String(); 
 
			if( !returned.Substring(0,3).Equals("+OK") ) 
			{ 
				throw new  
					Pop3LoginException("login/password not accepted"); 
			} 
		} 
 
		public long MessageCount 
		{ 
			get  
			{ 
				long count = 0; 
			 
				if(m_socket==null) 
				{ 
					throw new Pop3MessageException("Pop3 server not connected"); 
				} 
 
				Send("stat"); 
 
				string returned = GetPop3String(); 
 
				// if values returned ... 
				if( Regex.Match(returned, 
					@"^.*\+OK[ |	]+([0-9]+)[ |	]+.*$").Success ) 
				{ 
						// get number of emails ... 
						count = long.Parse( Regex 
						.Replace(returned.Replace("\r\n","") 
						, @"^.*\+OK[ |	]+([0-9]+)[ |	]+.*$" ,"$1") ); 
				} 
 
				return(count); 
			} 
		} 
 
 
		public void CloseConnection() 
		{			 
			Send("quit"); 
 
			m_socket = null; 
			m_pop3Message = null; 
		} 
 
		public bool DeleteEmail() 
		{ 
			bool ret = false; 
 
			Send("dele "+m_inboxPosition); 
 
			string returned = GetPop3String(); 
 
			if( Regex.Match(returned, 
				@"^.*\+OK.*$").Success ) 
			{ 
				ret = true; 
			} 
 
			return ret; 
		} 
 
		public bool NextEmail(long directPosition) 
		{ 
			bool ret; 
 
			if( directPosition >= 0 ) 
			{ 
				m_directPosition = directPosition; 
				ret = NextEmail(); 
			} 
			else 
			{ 
				throw new Pop3MessageException("Position less than zero"); 
			} 
 
			return ret; 
		} 
 
		public bool NextEmail() 
		{ 
			string returned; 
 
			long pos; 
 
			if(m_directPosition == -1) 
			{ 
				if(m_inboxPosition == 0) 
				{ 
					pos = 1; 
				} 
				else 
				{ 
					pos = m_inboxPosition + 1; 
				} 
			} 
			else 
			{ 
				pos = m_directPosition+1; 
				m_directPosition = -1; 
			} 
 
			// send username ... 
			Send("list "+pos.ToString()); 
		 
			// get response ... 
			returned = GetPop3String(); 
 
			// if email does not exist at this position 
			// then return false ... 
 
			if( returned.Substring(0,4).Equals("-ERR") ) 
			{ 
				return false; 
			} 
 
			m_inboxPosition = pos; 
 
			// strip out CRLF ... 
			string[] noCr = returned.Split(new char[]{ '\r' }); 
 
			// get size ... 
			string[] elements = noCr[0].Split(new char[]{ ' ' }); 
 
			long size = long.Parse(elements[2]); 
 
			// ... else read email data 
			m_pop3Message = new Pop3Message(m_inboxPosition,size,m_socket); 
 
			return true; 
		} 
 
		public void OpenInbox() 
		{ 
			// get a socket ... 
			m_socket = GetClientSocket(); 
 
			// get initial header from POP3 server ... 
			string header = GetPop3String(); 
 
			if( !header.Substring(0,3).Equals("+OK") ) 
			{ 
				throw new Exception("Invalid initial POP3 response"); 
			} 
		 
			// send login details ... 
			LoginToInbox(); 
		} 
	} 
}