C#使用POP3接收电子邮件

using System;

using System.Drawing;

using System.Collections;

using System.ComponentModel;

using System.Windows.Forms;

using System.Data;

using System.Net;

using System.Net.Sockets;

using System.IO;

namespace EmailReceiver

{

/// <summary>

/// Form1 的摘要说明。

/// </summary>

public class Form1 : System.Windows.Forms.Form

{

private System.Windows.Forms.Label label1;

private System.Windows.Forms.Label label2;

private System.Windows.Forms.Label label3;

private System.Windows.Forms.TextBox textBox1;

private System.Windows.Forms.TextBox textBox2;

private System.Windows.Forms.TextBox textBox3;

private System.Windows.Forms.TextBox textBox4;

private System.Windows.Forms.Button button1;

private System.Windows.Forms.Button button2;

private TcpClient Server;

private string SendString;

private byte[] BufferString;

private NetworkStream networkstream;

private StreamReader streamreader;

private System.Windows.Forms.RichTextBox richTextBox1;

private System.Windows.Forms.Button button3;

private System.Windows.Forms.Label label4;

/// <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 Form Designer generated code

/// <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.label1 = new System.Windows.Forms.Label();

this.label2 = new System.Windows.Forms.Label();

this.label3 = new System.Windows.Forms.Label();

this.textBox1 = new System.Windows.Forms.TextBox();

this.textBox2 = new System.Windows.Forms.TextBox();

this.textBox3 = new System.Windows.Forms.TextBox();

this.textBox4 = new System.Windows.Forms.TextBox();

this.button1 = new System.Windows.Forms.Button();

this.button2 = new System.Windows.Forms.Button();

this.richTextBox1 = new System.Windows.Forms.RichTextBox();

this.button3 = new System.Windows.Forms.Button();

this.label4 = new System.Windows.Forms.Label();

this.SuspendLayout();

//

// label1

//

this.label1.Location = new System.Drawing.Point(16, 8);

this.label1.Name = "label1";

this.label1.Size = new System.Drawing.Size(88, 16);

this.label1.TabIndex = 0;

this.label1.Text = "POP3 Server:";

//

// label2

//

this.label2.Location = new System.Drawing.Point(16, 40);

this.label2.Name = "label2";

this.label2.Size = new System.Drawing.Size(72, 16);

this.label2.TabIndex = 1;

this.label2.Text = "User Name:";

//

// label3

//

this.label3.Location = new System.Drawing.Point(16, 72);

this.label3.Name = "label3";

this.label3.Size = new System.Drawing.Size(72, 16);

this.label3.TabIndex = 2;

this.label3.Text = "Password:";

//

// textBox1

//

this.textBox1.Location = new System.Drawing.Point(96, 8);

this.textBox1.Name = "textBox1";

this.textBox1.Size = new System.Drawing.Size(168, 21);

this.textBox1.TabIndex = 3;

this.textBox1.Text = "";

//

// textBox2

//

this.textBox2.Location = new System.Drawing.Point(96, 40);

this.textBox2.Name = "textBox2";

this.textBox2.Size = new System.Drawing.Size(168, 21);

this.textBox2.TabIndex = 4;

this.textBox2.Text = "";

//

// textBox3

//

this.textBox3.Location = new System.Drawing.Point(96, 72);

this.textBox3.Name = "textBox3";

this.textBox3.PasswordChar = '*';

this.textBox3.Size = new System.Drawing.Size(168, 21);

this.textBox3.TabIndex = 5;

this.textBox3.Text = "";

//

// textBox4

//

this.textBox4.Location = new System.Drawing.Point(136, 152);

this.textBox4.Multiline = true;

this.textBox4.Name = "textBox4";

this.textBox4.Size = new System.Drawing.Size(64, 24);

this.textBox4.TabIndex = 6;

this.textBox4.Text = "";

this.textBox4.WordWrap = false;

//

// button1

//

this.button1.Location = new System.Drawing.Point(64, 112);

this.button1.Name = "button1";

this.button1.Size = new System.Drawing.Size(72, 24);

this.button1.TabIndex = 7;

this.button1.Text = "Connect";

this.button1.Click += new System.EventHandler(this.ConnectBtn_click);

//

// button2

//

this.button2.Location = new System.Drawing.Point(176, 112);

this.button2.Name = "button2";

this.button2.Size = new System.Drawing.Size(80, 24);

this.button2.TabIndex = 8;

this.button2.Text = "Disconnect";

this.button2.Click += new System.EventHandler(this.DisconBtn_click);

//

// richTextBox1

//

this.richTextBox1.Location = new System.Drawing.Point(8, 184);

this.richTextBox1.Name = "richTextBox1";

this.richTextBox1.ScrollBars = System.Windows.Forms.RichTextBoxScrollBars.Vertical;

this.richTextBox1.Size = new System.Drawing.Size(304, 168);

this.richTextBox1.TabIndex = 11;

this.richTextBox1.Text = "";

//

// button3

//

this.button3.Location = new System.Drawing.Point(216, 152);

this.button3.Name = "button3";

this.button3.Size = new System.Drawing.Size(56, 24);

this.button3.TabIndex = 12;

this.button3.Text = "Receive";

this.button3.Click += new System.EventHandler(this.ReceiveBtn_click);

//

// label4

//

this.label4.Location = new System.Drawing.Point(8, 152);

this.label4.Name = "label4";

this.label4.Size = new System.Drawing.Size(112, 24);

this.label4.TabIndex = 13;

this.label4.Text = "Enter the number:";

//

// Form1

//

this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);

this.ClientSize = new System.Drawing.Size(328, 366);

this.Controls.AddRange(new System.Windows.Forms.Control[] {

this.label4,

this.button3,

this.richTextBox1,

this.button2,

this.button1,

this.textBox4,

this.textBox3,

this.textBox2,

this.textBox1,

this.label3,

this.label2,

this.label1});

this.Name = "Form1";

this.Text = "EmailReceiver";

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 ConnectBtn_click(object sender, System.EventArgs e)

{

Server=new TcpClient(textBox1.Text,110);

networkstream= Server.GetStream();

streamreader=new StreamReader(networkstream);

try

{

SendString="USER "+textBox2.Text+"\r\n";

BufferString=System.Text.Encoding.ASCII.GetBytes(SendString.ToCharArray());

networkstream.Write(BufferString,0,BufferString.Length);

richTextBox1.AppendText(streamreader.ReadLine()+"\r\n");

SendString="PASS "+textBox3.Text+"\r\n";

BufferString=System.Text.Encoding.ASCII.GetBytes(SendString.ToCharArray());

networkstream.Write(BufferString,0,BufferString.Length);

richTextBox1.AppendText(streamreader.ReadLine()+"\r\n");

SendString="STAT"+"\r\n";

BufferString=System.Text.Encoding.ASCII.GetBytes(SendString.ToCharArray());

networkstream.Write(BufferString,0,BufferString.Length);

richTextBox1.AppendText(streamreader.ReadLine()+"\r\n");

SendString="LIST"+"\r\n";

BufferString=System.Text.Encoding.ASCII.GetBytes(SendString.ToCharArray());

networkstream.Write(BufferString,0,BufferString.Length);

richTextBox1.AppendText(streamreader.ReadLine()+"\r\n");

}

catch(InvalidOperationException err)

{MessageBox.Show(err.ToString());}

}

private void DisconBtn_click(object sender, System.EventArgs e)

{

try

{

SendString="QUIT\r\n";

BufferString=System.Text.Encoding.ASCII.GetBytes(SendString.ToCharArray());

networkstream.Write(BufferString,0,BufferString.Length);

richTextBox1.AppendText(streamreader.ReadLine()+"\r\n");

networkstream.Close();

streamreader.Close();

}

catch{MessageBox.Show("The Connection has not exist!");}

}

private void ReceiveBtn_click(object sender, System.EventArgs e)

{

string TempString;

TempString=" ";

richTextBox1.Clear();

SendString="RETR "+textBox4.Text+"\r\n";

BufferString=System.Text.Encoding.ASCII.GetBytes(SendString.ToCharArray());

networkstream.Write(BufferString,0,BufferString.Length);

TempString=streamreader.ReadLine();

if(TempString[0]!='-')

{

while(TempString!=".")

{

TempString=streamreader.ReadLine();

}

TempString=streamreader.ReadLine();

while(TempString!=".")

{

richTextBox1.AppendText(TempString+"\r\n");

TempString=streamreader.ReadLine();

}

}

else

{

richTextBox1.AppendText("\r\n Error!\r\n");

}

}

}

}