Email客户端

开发平台：
Visual C++

Form1.cs：源码内容
							using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Net ;
using System.IO;
using System.Net.Sockets ;
using System.Text ;
//Download by http://www.codefans.net
namespace MailPOP3
{
	/// <summary>
	/// Form1 的摘要说明。
	/// </summary>
	public class Form1 : System.Windows.Forms.Form
	{
		private System.Windows.Forms.GroupBox groupBox1;
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.Label label2;
		private System.Windows.Forms.Label label3;
		private System.Windows.Forms.Label label4;
		private System.Windows.Forms.GroupBox groupBox2;
		private System.Windows.Forms.GroupBox groupBox3;
		private System.Windows.Forms.TextBox servername;
		private System.Windows.Forms.TextBox mailport;
		private System.Windows.Forms.TextBox password;
		private System.Windows.Forms.TextBox username;
		private System.Windows.Forms.Button receive;
		private System.Windows.Forms.RichTextBox richTextBox1;
		private System.Windows.Forms.RichTextBox richTextBox2;
		/// <summary>
		/// 必需的设计器变量。
		/// </summary>
		private System.ComponentModel.Container components = null;
		public Form1()
		{
			//
			// Windows 窗体设计器支持所必需的
			//
			InitializeComponent();
			//
			// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
			//
		}
		/// <summary>
		/// 清理所有正在使用的资源。
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}
		#region Windows 窗体设计器生成的代码
		/// <summary>
		/// 设计器支持所需的方法 - 不要使用代码编辑器修改
		/// 此方法的内容。
		/// </summary>
		private void InitializeComponent()
		{
			this.groupBox1 = new System.Windows.Forms.GroupBox();
			this.label1 = new System.Windows.Forms.Label();
			this.servername = new System.Windows.Forms.TextBox();
			this.mailport = new System.Windows.Forms.TextBox();
			this.password = new System.Windows.Forms.TextBox();
			this.username = new System.Windows.Forms.TextBox();
			this.label2 = new System.Windows.Forms.Label();
			this.label3 = new System.Windows.Forms.Label();
			this.label4 = new System.Windows.Forms.Label();
			this.groupBox2 = new System.Windows.Forms.GroupBox();
			this.groupBox3 = new System.Windows.Forms.GroupBox();
			this.receive = new System.Windows.Forms.Button();
			this.richTextBox1 = new System.Windows.Forms.RichTextBox();
			this.richTextBox2 = new System.Windows.Forms.RichTextBox();
			this.groupBox1.SuspendLayout();
			this.groupBox2.SuspendLayout();
			this.groupBox3.SuspendLayout();
			this.SuspendLayout();
			// 
			// groupBox1
			// 
			this.groupBox1.Controls.Add(this.label1);
			this.groupBox1.Controls.Add(this.servername);
			this.groupBox1.Controls.Add(this.mailport);
			this.groupBox1.Controls.Add(this.password);
			this.groupBox1.Controls.Add(this.username);
			this.groupBox1.Controls.Add(this.label2);
			this.groupBox1.Controls.Add(this.label3);
			this.groupBox1.Controls.Add(this.label4);
			this.groupBox1.Location = new System.Drawing.Point(4, 4);
			this.groupBox1.Name = "groupBox1";
			this.groupBox1.Size = new System.Drawing.Size(490, 82);
			this.groupBox1.TabIndex = 0;
			this.groupBox1.TabStop = false;
			this.groupBox1.Text = "接收邮件服务器设置";
			// 
			// label1
			// 
			this.label1.Location = new System.Drawing.Point(10, 26);
			this.label1.Name = "label1";
			this.label1.Size = new System.Drawing.Size(64, 16);
			this.label1.TabIndex = 1;
			this.label1.Text = "服务器名:";
			// 
			// servername
			// 
			this.servername.Location = new System.Drawing.Point(76, 22);
			this.servername.Name = "servername";
			this.servername.Size = new System.Drawing.Size(174, 21);
			this.servername.TabIndex = 0;
			this.servername.Text = "";
			// 
			// mailport
			// 
			this.mailport.Location = new System.Drawing.Point(76, 52);
			this.mailport.Name = "mailport";
			this.mailport.Size = new System.Drawing.Size(174, 21);
			this.mailport.TabIndex = 0;
			this.mailport.Text = "";
			// 
			// password
			// 
			this.password.Location = new System.Drawing.Point(306, 52);
			this.password.Name = "password";
			this.password.Size = new System.Drawing.Size(174, 21);
			this.password.TabIndex = 0;
			this.password.Text = "";
			// 
			// username
			// 
			this.username.Location = new System.Drawing.Point(306, 22);
			this.username.Name = "username";
			this.username.Size = new System.Drawing.Size(174, 21);
			this.username.TabIndex = 0;
			this.username.Text = "";
			// 
			// label2
			// 
			this.label2.Location = new System.Drawing.Point(38, 56);
			this.label2.Name = "label2";
			this.label2.Size = new System.Drawing.Size(36, 14);
			this.label2.TabIndex = 1;
			this.label2.Text = "端口:";
			// 
			// label3
			// 
			this.label3.Location = new System.Drawing.Point(260, 26);
			this.label3.Name = "label3";
			this.label3.Size = new System.Drawing.Size(48, 14);
			this.label3.TabIndex = 1;
			this.label3.Text = "用户名:";
			// 
			// label4
			// 
			this.label4.Location = new System.Drawing.Point(272, 56);
			this.label4.Name = "label4";
			this.label4.Size = new System.Drawing.Size(36, 16);
			this.label4.TabIndex = 1;
			this.label4.Text = "密码:";
			// 
			// groupBox2
			// 
			this.groupBox2.Controls.Add(this.richTextBox1);
			this.groupBox2.Location = new System.Drawing.Point(4, 90);
			this.groupBox2.Name = "groupBox2";
			this.groupBox2.Size = new System.Drawing.Size(562, 100);
			this.groupBox2.TabIndex = 2;
			this.groupBox2.TabStop = false;
			this.groupBox2.Text = "邮件名称";
			// 
			// groupBox3
			// 
			this.groupBox3.Controls.Add(this.richTextBox2);
			this.groupBox3.Location = new System.Drawing.Point(2, 194);
			this.groupBox3.Name = "groupBox3";
			this.groupBox3.Size = new System.Drawing.Size(564, 224);
			this.groupBox3.TabIndex = 3;
			this.groupBox3.TabStop = false;
			this.groupBox3.Text = "邮件内容";
			// 
			// receive
			// 
			this.receive.Location = new System.Drawing.Point(498, 30);
			this.receive.Name = "receive";
			this.receive.Size = new System.Drawing.Size(64, 23);
			this.receive.TabIndex = 4;
			this.receive.Text = "接收邮件";
			this.receive.Click += new System.EventHandler(this.receive_Click);
			// 
			// richTextBox1
			// 
			this.richTextBox1.Dock = System.Windows.Forms.DockStyle.Fill;
			this.richTextBox1.Location = new System.Drawing.Point(3, 17);
			this.richTextBox1.Name = "richTextBox1";
			this.richTextBox1.Size = new System.Drawing.Size(556, 80);
			this.richTextBox1.TabIndex = 1;
			this.richTextBox1.Text = "";
			// 
			// richTextBox2
			// 
			this.richTextBox2.Dock = System.Windows.Forms.DockStyle.Fill;
			this.richTextBox2.Location = new System.Drawing.Point(3, 17);
			this.richTextBox2.Name = "richTextBox2";
			this.richTextBox2.Size = new System.Drawing.Size(558, 204);
			this.richTextBox2.TabIndex = 0;
			this.richTextBox2.Text = "";
			// 
			// Form1
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
			this.ClientSize = new System.Drawing.Size(568, 424);
			this.Controls.Add(this.receive);
			this.Controls.Add(this.groupBox3);
			this.Controls.Add(this.groupBox2);
			this.Controls.Add(this.groupBox1);
			this.MaximizeBox = false;
			this.Name = "Form1";
			this.Text = "邮件接收";
			this.groupBox1.ResumeLayout(false);
			this.groupBox2.ResumeLayout(false);
			this.groupBox3.ResumeLayout(false);
			this.ResumeLayout(false);
		}
		#endregion
		/// <summary>
		/// 应用程序的主入口点。
		/// </summary>
		[STAThread]
		static void Main() 
		{
			Application.Run(new Form1());
		}
		private void receive_Click(object sender, System.EventArgs e)
		{
			int mailnumber;
			//连接服务器
			TcpClient tcpClient=new TcpClient();
			try
			{
				//连接POP3服务器
				tcpClient.Connect(servername.Text,Int32.Parse (mailport.Text));
			}
			catch
			{
				//显示错误信息
				MessageBox.Show ("无法连接到POP3服务器"+servername.Text+"的"+mailport.Text+"端口!");
			}
			//从POP3邮件服务器取得回复
			NetworkStream netStream=tcpClient.GetStream ();
			if (netStream==null)
			{
				throw new Exception ("无法取得回复");
			}
			string returnMsg=ReadFromNetStream(ref netStream);
			checkForError(returnMsg);
			richTextBox1.AppendText("连接应答:"+returnMsg+"rn");
			//发送用户名信息
			richTextBox1.AppendText("C:USER "+this.username.Text+"rn");
			WriteToNetStream(ref netStream,"USER "+this.username.Text);
			returnMsg=ReadFromNetStream(ref netStream);
			checkForError(returnMsg);
			richTextBox1.AppendText("POP3SERVER:"+returnMsg+"rn");
			//发送用户密码信息
			richTextBox1.AppendText("C:PASSWORD "+this.password.Text+"rn");
			WriteToNetStream(ref netStream,"PASS "+this.password .Text);
			returnMsg=ReadFromNetStream(ref netStream);
			checkForError(returnMsg);
			richTextBox1.AppendText("POP3SERVER:"+returnMsg+"rn");
			//检查邮件
			mailnumber=EmailCheck(ref netStream);
			richTextBox1.AppendText("邮件数:"+mailnumber+"　rn");
			//接收邮件
			for (int i=1;i<=mailnumber;i++)
			{
				richTextBox1.AppendText("C:RETR "+i.ToString() +"　rn");
				WriteToNetStream(ref netStream,"RETR "+i.ToString());
				returnMsg=ReadFromNetStream(ref netStream);
				checkForError(returnMsg);
				richTextBox1.AppendText("POP3SERVER:"+returnMsg+"rn");
				ReadMail(ref netStream,i);
			}
			//断开与POP3服务器的连接
			richTextBox1.AppendText("C:QUIT rn");
			WriteToNetStream(ref netStream,"QUIT ");
			returnMsg=ReadFromNetStream(ref netStream);
			checkForError(returnMsg);
			richTextBox1.AppendText("POP3SERVER:"+returnMsg+"rn");
		}
				
		//邮件检查
		private int EmailCheck(ref NetworkStream NetStream)
		{
			richTextBox1.AppendText("C:STAT　rn");
			WriteToNetStream(ref NetStream,"STAT");
			string returnMsg=ReadFromNetStream(ref NetStream);
			checkForError(returnMsg);
			richTextBox1.AppendText("POP3SERVER:"+returnMsg+"rn");
			string[] TotalStat=returnMsg.Split (new char[] {' '});
			int mailNumber=Int32.Parse (TotalStat[1]);
			return mailNumber;
		}
		//向POP3服务器写入命令
		private void WriteToNetStream(ref NetworkStream NetStream,string Command)
		{
			string stringToSend=Command+"rn";
			Byte[] arrayToSend=Encoding.ASCII.GetBytes(stringToSend.ToCharArray());
			NetStream.Write(arrayToSend,0,arrayToSend.Length );
		}
		
		//从POP3读取数据
		private string ReadFromNetStream(ref NetworkStream NetStream)
		{
			StringBuilder strReceived=new StringBuilder();
			StreamReader sr=new StreamReader (NetStream);
			String strLine=sr.ReadLine ();
			while(strLine==null || strLine.Length ==0)
			{
				strLine=sr.ReadLine ();
			}
			strReceived.Append(strLine);
			if (sr.Peek ()!=-1)
			{
				while((strLine=sr.ReadLine ())!=null)
				{
					strReceived.Append(strLine);
				}
			}
			return strReceived.ToString();
		}
		//检查流中是否含有错误
		private void checkForError(String strMessage)
		{
			if (strMessage.IndexOf ("+OK")==-1)
				throw new Exception ("收到来自POP3服务器的错误信息:"+strMessage);
		}
       //读邮件
		private void ReadMail(ref NetworkStream NetStream,int number)
		{
			int k=0;
			bool check=false;
			byte[] bb=new byte [6400];
			while(!check)
			{
				k=NetStream.Read (bb,0,bb.Length );
				string read=System.Text .Encoding .UTF8.GetString (bb,0,k);
				int x=read.IndexOf ("rn.rn");
				if (x!=-1)
				{
					check=true;
				}
				richTextBox2.AppendText (read);
				richTextBox1.AppendText("C:DELE "+number.ToString ()+"rn");
				WriteToNetStream(ref NetStream,"DELE "+number.ToString ());
				string returnMsg=ReadFromNetStream(ref NetStream);
				checkForError(returnMsg);
				richTextBox1.AppendText("POP3SERVER:"+returnMsg+"rn");
			}
		}
	}
}

						