首先从原理上解释一下采用Socket接口的网络通讯,这里以最常用的C/S模式作为范例,首先,服务端有一个进程(或多个进程)在指定的端口等待客户来连接,服务程序等待客户的连接信息,一旦连接上之后,就可以按设计的数据交换方法和格式进行数据传输。客户端在需要的时刻发出向服务端的连接请求。这里为了便于理解,提到了一些调用及其大致的功能。使用socket调用后,仅产生了一个可以使用的socket描述符,这时还不能进行通信,还要使用其他的调用,以使得socket所指的结构中使用的信息被填写完。
在使用TCP协议时,一般服务端进程先使用socket调用得到一个描述符,然后使用bind调用将一个名字与socket描述符连接起来,对于Internet域就是将Internet地址联编到socket。之后,服务端使用listen调用指出等待服务请求队列的长度。然后就可以使用accept调用等待客户端发起连接,一般是阻塞等待连接,一旦有客户端发出连接,accept返回客户的地址信息,并返回一个新的socket描述符,该描述符与原先的socket有相同的特性,这时服务端就可以使用这个新的socket进行读写操作了。一般服务端可能在accept返回后创建一个新的进程进行与客户的通信,父进程则再到accept调用处等待另一个连接。客户端进程一般先使用socket调用得到一个socket描述符,然后使用connect向指定的服务器上的指定端口发起连接,一旦连接成功返回,就说明已经建立了与服务器的连接,这时就可以通过socket描述符进行读写操作了。
.NetFrameWork为Socket通讯提供了System.Net.Socket命名空间,在这个命名空间里面有以下几个常用的重要类分别是:
Socket类 这个低层的类用于管理连接,WebRequest,TcpClient和UdpClient在内部使用这个类。
NetworkStream类 这个类是从Stream派生出来的,它表示来自网络的数据流
TcpClient类 允许创建和使用TCP连接
TcpListener类 允许监听传入的TCP连接请求
UdpClient类 用于UDP客户创建连接(UDP是另外一种TCP协议,但没有得到广泛的使用,主要用于本地网络)
下面我们来看一个基于Socket的双机通信代码的C#版本
(本文来源于图老师网站,更多请访问http://m.tulaoshi.com/bianchengyuyan/)首先创建Socket对象的实例,这可以通过Socket类的构造方法来实现:
public Socket(AddressFamily addressFamily,SocketType socketType,ProtocolType protocolType);
其中,addressFamily 参数指定 Socket 使用的寻址方案,socketType 参数指定 Socket 的类型,protocolType 参数指定 Socket 使用的协议。
下面的示例语句创建一个 Socket,它可用于在基于 TCP/IP 的网络(如 Internet)上通讯。
Socket temp = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
若要使用 UDP 而不是 TCP,需要更改协议类型,如下面的示例所示:
(本文来源于图老师网站,更多请访问http://m.tulaoshi.com/bianchengyuyan/)
Socket temp = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
一旦创建 Socket,在客户端,你将可以通过Connect方法连接到指定的服务器(你可以在Connect方法前Bind端口,就是以指定的端口发起连接,如果不事先Bind端口号的话,系统会默认在1024到5000随机绑定一个端口号),并通过Send方法向远程服务器发送数据,而后可以通过Receive从服务端接收数据;而在服务器端,你需要使用Bind方法绑定所指定的接口使Socket与一个本地终结点相联,并通过Listen方法侦听该接口上的请求,当侦听到用户端的连接时,调用Accept完成连接的操作,创建新的Socket以处理传入的连接请求。使用完 Socket 后,使用 Close 方法关闭 Socket。
可以看出,以上许多方法包含EndPoint类型的参数,在Internet中,TCP/IP 使用一个网络地址和一个服务端口号来唯一标识设备。网络地址标识网络上的特定设备;端口号标识要连接到的该设备上的特定服务。网络地址和服务端口的组合称为终结点,在 .NET 框架中正是由 EndPoint 类表示这个终结点,它提供表示网络资源或服务的抽象,用以标志网络地址等信息。.Net同时也为每个受支持的地址族定义了 EndPoint 的子代;对于 IP 地址族,该类为 IPEndPoint。IPEndPoint 类包含应用程序连接到主机上的服务所需的主机和端口信息,通过组合服务的主机IP地址和端口号,IPEndPoint 类形成到服务的连接点。
用到IPEndPoint类的时候就不可避免地涉及到计算机IP地址,System.Net命名空间中有两种类可以得到IP地址实例:
IPAddress类:IPAddress 类包含计算机在 IP 网络上的地址。其Parse方法可将 IP 地址字符串转换为 IPAddress 实例。下面的语句创建一个 IPAddress 实例:
IPAddress myIP = IPAddress.Parse("192.168.0.1");
需要知道的是:Socket 类支持两种基本模式:同步和异步。其区别在于:在同步模式中,按块传输,对执行网络操作的函数(如 Send 和 Receive)的调用一直等到所有内容传送操作完成后才将控制返回给调用程序。在异步模式中,是按位传输,需要指定发送的开始和结束。同步模式是最常用的模式,我们这里的例子也是使用同步模式。
下面看一个完整的例子,client向server发送一段测试字符串,server接收并显示出来,给予client成功响应。
//client端using System;using System.Text;using System.IO;using System.Net;using System.Net.Sockets;namespace socketsample{ class Class1 { static void Main() { try { int port = 2000; string host = "127.0.0.1"; IPAddress ip = IPAddress.Parse(host); IPEndPoint ipe = new IPEndPoint(ip, port);//把ip和端口转化为IPEndPoint实例 Socket c = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);//创建一个Socket Console.WriteLine("Conneting..."); c.Connect(ipe);//连接到服务器 string sendStr = "hello!This is a socket test"; byte[] bs = Encoding.ASCII.GetBytes(sendStr); Console.WriteLine("Send Message"); c.Send(bs, bs.Length, 0);//发送测试信息 string recvStr = ""; byte[] recvBytes = new byte[1024]; int bytes; bytes = c.Receive(recvBytes, recvBytes.Length, 0);//从服务器端接受返回信息 recvStr += Encoding.ASCII.GetString(recvBytes, 0, bytes); Console.WriteLine("Client Get Message:{0}", recvStr);//显示服务器返回信息 c.Close(); } catch (ArgumentNullException e) { Console.WriteLine("ArgumentNullException: {0}", e); } catch (SocketException e) { Console.WriteLine("SocketException: {0}", e); } Console.WriteLine("Press Enter to Exit"); Console.ReadLine(); } }}//server端using System;using System.Text;using System.IO;using System.Net;using System.Net.Sockets;namespace Project1{ class Class2 { static void Main() { try { int port = 2000; string host = "127.0.0.1"; IPAddress ip = IPAddress.Parse(host); IPEndPoint ipe = new IPEndPoint(ip, port); Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);//创建一个Socket类 s.Bind(ipe);//绑定2000端口 s.Listen(0);//开始监听 Console.WriteLine("Wait for connect"); Socket temp = s.Accept();//为新建连接创建新的Socket。 Console.WriteLine("Get a connect"); string recvStr = ""; byte[] recvBytes = new byte[1024]; int bytes; bytes = temp.Receive(recvBytes, recvBytes.Length, 0);//从客户端接受信息 recvStr += Encoding.ASCII.GetString(recvBytes, 0, bytes); Console.WriteLine("Server Get Message:{0}",recvStr);//把客户端传来的信息显示出来 string sendStr = "Ok!Client Send Message Sucessful!"; byte[] bs = Encoding.ASCII.GetBytes(sendStr); temp.Send(bs, bs.Length, 0);//返回客户端成功信息 temp.Close(); s.Close(); } catch (ArgumentNullException e) { Console.WriteLine("ArgumentNullException: {0}", e); } catch (SocketException e) { Console.WriteLine("SocketException: {0}", e); } Console.WriteLine("Press Enter to Exit"); Console.ReadLine(); } }}
上面的例子是用的Socket类,System.Net.Socket命名空间还提供了两个抽象高级类TCPClient和UDPClient和用于通讯流处理的NetWorkStream,让我们看下例子
客户端
TcpClient tcpClient=new TcpCLient(主机IP,端口号);NetworkStream ns=tcp.Client.GetStream();
服务端
TcpListener tcpListener=new TcpListener(监听端口);tcpListener.Start();TcpClient tcpClient=tcpListener.AcceptTcpClient();NetworkStream ns=tcpClient.GetStream();
服务端用TcpListener监听,然后把连接的对象实例化为一个TcpClient,调用TcpClient.GetStream()方法,返回网络流实例化为一个NetworlStream流,下面就是用流的方法进行Send,Receive
如果是UdpClient的话,就直接UdpClient实例化,然后调用UdpClient的Send和Receive方法,需要注意的事,UdpClient没有返回网络流的方法,就是说没有GetStream方法,所以无法流化,而且使用Udp通信的时候,不要服务器监听。
现在我们大致了解了.Net Socket通信的流程,下面我们来作一个稍微复杂点的程序,一个广播式的C/S聊天程序。
客户端设计需要一个1个ListBox,用于显示聊天内容,一个TextBox输入你要说的话,一个Button发送留言,一个Button建立连接。
点击建立连接的Button后出来一个对话框,提示输入连接服务器的IP,端口,和你的昵称,启动一个接受线程,负责接受从服务器传来的信息并显示在ListBox上面。
服务器端2个Button,一个启动服务,一个T掉已建立连接的客户端,一个ListBox显示连接上的客户端的Ip和端口。
比较重要的地方是字符串编码的问题,需要先把需要传送的字符串按照UTF8编码,然后接受的时候再还原成为GB2312,不然中文显示会是乱码。
还有一个就是接收线程,我这里简单写成一个While(ture)循环,不断判断是否有信息流入,有就接收,并显示在ListBox上,这里有问题,在.Net2.0里面,交错线程修改窗体空间属性的时候会引发一个异常,不可以直接修改,需要定义一个委托来修改。
当客户端需要断开连接的时候,比如点击窗体右上角的XX,就需要定义一个this.FormClosing += new System.Windows.Forms.FormClosingEventHandler(this.Closing);(.Net2.0是FormClosing系统事件),在Closing()函数里面,发送Close字符给服务端,服务器判断循环判断所有的连接上的客户端传来的信息,如果是以Close开头,断开与其的连接。看到这里,读者就会问了,如果我在聊天窗口输入Close是不是也断开连接呢?不是的,在聊天窗口输入的信息传给服务器的时候开头都要加上Ip信息和昵称,所以不会冲突。
客户端
// Form1.Designer.csnamespace ClientTest{ partial class Form1 { /// summary /// Required designer variable. /// /summary private System.ComponentModel.IContainer components = null; /// summary /// Clean up any resources being used. /// /summary /// param name="disposing"true if managed resources should be disposed; otherwise, false./param protected override void Dispose(bool disposing) { if (disposing && (components != null)) { components.Dispose(); } base.Dispose(disposing); } #region Windows Form Designer generated code /// summary /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// /summary private void InitializeComponent() { this.listBox1 = new System.Windows.Forms.ListBox(); this.button1 = new System.Windows.Forms.Button(); this.textBox1 = new System.Windows.Forms.TextBox(); this.button3 = new System.Windows.Forms.Button(); this.SuspendLayout(); // // listBox1 // this.listBox1.FormattingEnabled = true; this.listBox1.ItemHeight = 12; this.listBox1.Location = new System.Drawing.Point(12, 12); this.listBox1.Name = "listBox1"; this.listBox1.Size = new System.Drawing.Size(268, 148); this.listBox1.TabIndex = 0; // // button1 // this.button1.Location = new System.Drawing.Point(12, 166); this.button1.Name = "button1"; this.button1.Size = new System.Drawing.Size(268, 35); this.button1.TabIndex = 1; this.button1.Text = "连接"; this.button1.UseVisualStyleBackColor = true; this.button1.Click += new System.EventHandler(this.button1_Click); // // textBox1 // this.textBox1.Location = new System.Drawing.Point(12, 207); this.textBox1.Multiline = true; this.textBox1.Name = "textBox1"; this.textBox1.Size = new System.Drawing.Size(211, 54); this.textBox1.TabIndex = 3; // // button3 // this.button3.Location = new System.Drawing.Point(229, 207); this.button3.Name = "button3"; this.button3.Size = new System.Drawing.Size(51, 54); this.button3.TabIndex = 4; this.button3.Text = "发言"; this.button3.UseVisualStyleBackColor = true; this.button3.Click += new System.EventHandler(this.button3_Click); // // Form1 // this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F); this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; this.ClientSize = new System.Drawing.Size(292, 273); this.Controls.Add(this.button3); this.Controls.Add(this.textBox1); this.Controls.Add(this.button1); this.Controls.Add(this.listBox1); this.Name = "Form1"; this.Text = "客户端"; this.FormClosing += new System.Windows.Forms.FormClosingEventHandler(this.Closing); this.Load += new System.EventHandler(this.Form1_Load); this.ResumeLayout(false); this.PerformLayout(); } #endregion private System.Windows.Forms.ListBox listBox1; private System.Windows.Forms.Button button1; private System.Windows.Forms.TextBox textBox1; private System.Windows.Forms.Button button3; }}//Form1.csusing System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Text;using System.Windows.Forms;using System.Net.Sockets;using System.IO;using System.Threading;namespace ClientTest{ public partial class Form1 : Form { Socket client; public string host = "";//要连接的服务器IP int port = 2000; Thread Data; public string nick = "";//给自己起一个昵称,呵呵 Encoding utf8 = Encoding.UTF8; Encoding gb2312 = Encoding.GetEncoding("GB2312"); delegate void SetSafe(string text); public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e)//连接服务器 { Form2 frm2 = new Form2(); frm2.ShowDialog();//显示一个对话框,输入服务器IP和自己的昵称 host = frm2.textBox2.Text; nick=frm2.textBox1.Text; try { client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); client.Connect(host, port);//连接服务器 } catch (Exception ex) { MessageBox.Show(ex.Message); } } private void Form1_Load(object sender, EventArgs e)//窗体载入时候开启一个数据处理线程,处理从服务器得到的数据 { Data = new Thread(new ThreadStart(DataStart)); Data.Start(); } public void DataStart()//只要能从服务器得到数据,就显示在ListBox上,这个过程一直循环 { while (true) { try { NetworkStream ns = new NetworkStream(client); StreamReader reader = new StreamReader(ns); string result =reader.ReadLine(); byte[] u = utf8.GetBytes(result); byte[] gb = Encoding.Convert(utf8, gb2312, u); string sGb = gb2312.GetString(gb); AddList(sGb); reader.Close(); ns.Close(); } catch { } Thread.Sleep(1000); } } private void button3_Click(object sender, EventArgs e)//发言 { try { string sendString = "("+ client.LocalEndPoint.ToString()+")"+nick+"说"+textBox1.Text + "rn"; byte[] butf = utf8.GetBytes(sendString); client.Send(butf);//按照昵称(IP)说的话的格式发送给服务器 } catch { } } private void AddList(object text) { // InvokeRequired required compares the thread ID of the // calling thread to the thread ID of the creating thread. // If these threads are different, it returns true. if (this.listBox1.InvokeRequired) { SetSafe d = new SetSafe(AddList); this.Invoke(d, new object[] { text }); } else { this.listBox1.Items.Add(text); } } private void Closing(object sender, System.EventArgs e)//断开连接,发送服务器"Close"信息 { try { Data.Abort(); Byte[] buf = System.Text.Encoding.UTF8.GetBytes("Close" + "rn"); client.Send(buf); } catch { } } }}//Form2.csusing System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Text;using System.Windows.Forms;namespace ClientTest{ public partial class Form2 : Form { public Form2() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { this.Hide(); } }}服务端// Form1.Designer.csnamespace ServerTest{ partial class Form1 { /// summary /// Required designer variable. /// /summary private System.ComponentModel.IContainer components = null; /// summary /// Clean up any resources being used. /// /summary /// param name="disposing"true if managed resources should be disposed; otherwise, false./param protected override void Dispose(bool disposing) { if (disposing && (components != null)) { components.Dispose(); } base.Dispose(disposing); } #region Windows Form Designer generated code /// summary /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// /summary private void InitializeComponent() { this.button1 = new System.Windows.Forms.Button(); this.listBox1 = new System.Windows.Forms.ListBox(); this.button2 = new System.Windows.Forms.Button(); this.SuspendLayout(); // // button1 // this.button1.Location = new System.Drawing.Point(12, 12); this.button1.Name = "button1"; this.button1.Size = new System.Drawing.Size(130, 44); this.button1.TabIndex = 0; this.button1.Text = "开启服务"; this.button1.UseVisualStyleBackColor = true; this.button1.Click += new System.EventHandler(this.button1_Click); // // listBox1 // this.listBox1.FormattingEnabled = true; this.listBox1.ItemHeight = 12; this.listBox1.Location = new System.Drawing.Point(12, 62); this.listBox1.Name = "listBox1"; this.listBox1.Size = new System.Drawing.Size(268, 196); this.listBox1.TabIndex = 1; // // button2 // this.button2.Location = new System.Drawing.Point(150, 12); this.button2.Name = "button2"; this.button2.Size = new System.Drawing.Size(130, 44); this.button2.TabIndex = 2; this.button2.Text = "T人"; this.button2.UseVisualStyleBackColor = true; this.button2.Click += new System.EventHandler(this.button2_Click); // // Form1 // this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F); this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; this.ClientSize = new System.Drawing.Size(292, 273); this.Controls.Add(this.button2); this.Controls.Add(this.listBox1); this.Controls.Add(this.button1); this.Name = "Form1"; this.Text = "服务端"; this.ResumeLayout(false); this.FormClosing+=new System.Windows.Forms.FormClosingEventHandler(Closing); } #endregion private System.Windows.Forms.Button button1; private System.Windows.Forms.ListBox listBox1; private System.Windows.Forms.Button button2; }}//Form1.csusing System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Text;using System.Windows.Forms;using System.Threading;using System.IO;using System.Net.Sockets;using System.Collections;namespace ServerTest{ public partial class Form1 : Form { int port = 2000;//绑定本机端口2000 TcpListener listener; delegate void SetSafe(string text); ArrayList conList=new ArrayList(); Encoding utf8 = Encoding.UTF8; Encoding gb2312 = Encoding.GetEncoding("GB2312"); Thread listenerThread; Thread DataThread; public Form1() { InitializeComponent(); } public void AcceptRequest() //连接处理线程 { try { while (true) { if (listener.Pending())//是否有等待连接队列 { Socket s = listener.AcceptSocket();//建立连接 conList.Add(s);//添加当前连接到已连接列表 if (s.Connected) { string ServerEndPoint = "欢迎登陆服务器" + s.LocalEndPoint.ToString() + "rn"; byte[] bgb = gb2312.GetBytes(ServerEndPoint); byte[] butf = Encoding.Convert(gb2312, utf8, bgb); s.Send(butf);//发送欢迎登陆信息 string mpoint = s.RemoteEndPoint.ToString(); AddList(mpoint);//把当前客户端IP,Port添加到ListBox显示 } } } } catch { } Thread.Sleep(1000); } public void ReceiveData()//数据处理线程 { while (true) { try { ArrayList CloseSocketList = new ArrayList();//关闭连接列表 CloseSocketList.Clear();//清空关闭连接列表 foreach (Socket s in conList)//循环每一个已建立的连接 { NetworkStream ns = new NetworkStream(s); StreamReader reader = new StreamReader(ns); if (ns.DataAvailable) { string result = reader.ReadLine(); byte[] u = utf8.GetBytes(result); byte[] gb = Encoding.Convert(utf8, gb2312, u); string sGb = gb2312.GetString(gb); if (sGb.StartsWith("Close"))//如果收到Close信息 { CloseSocketList.Add(s);//把当前连接添加到关闭连接列表 } else { foreach (Socket p in conList)//把从一个连接得到的信息发给所有的连接的客户端,就好比聊天室的聊天大厅,公共聊天 { string sendString = result + "rn"; byte[] butf = utf8.GetBytes(sendString); p.Send(butf); } } } reader.Close(); ns.Close(); } foreach (Socket s in CloseSocketList)//关闭关闭连接列表里面的连接 { DelList(s.RemoteEndPoint.ToString());//从ListBox删除关闭的连接 s.Close(); conList.Remove(s); } } catch { } Thread.Sleep(1000); } } private void button1_Click(object sender, EventArgs e)//启动服务器 { listener = new TcpListener(port);//开启2000端口的监听 listener.Start(); listenerThread = new Thread(new ThreadStart(AcceptRequest));//启动连接处理线程 listenerThread.Start(); DataThread = new Thread(new ThreadStart(ReceiveData));//启动数据处理线程 DataThread.Start(); } private void AddList(object text) { // InvokeRequired required compares the thread ID of the // calling thread to the thread ID of the creating thread. // If these threads are different, it returns true. if (this.listBox1.InvokeRequired) { SetSafe d = new SetSafe(AddList); this.Invoke(d, new object[] { text }); } else { this.listBox1.Items.Add(text); } } private void DelList(object text) { // InvokeRequired required compares the thread ID of the // calling thread to the thread ID of the creating thread. // If these threads are different, it returns true. if (this.listBox1.InvokeRequired) { SetSafe d = new SetSafe(DelList); this.Invoke(d, new object[] { text }); } else { this.listBox1.Items.Remove(text); } } private void button2_Click(object sender, EventArgs e)//踢指定的客户端连接 { try { string temp = listBox1.SelectedItem.ToString();//选择要踢的客户端 DelList(temp);//ListBox删除它 foreach (Socket f in conList) { if ((f.RemoteEndPoint.ToString()) == temp)//找到那个要踢的客户端 { string Message = "你被服务器T了" + "rn"; byte[] bgb = gb2312.GetBytes(Message); byte[] butf = Encoding.Convert(gb2312, utf8, bgb); f.Send(butf);//告诉他他被踢了 conList.Remove(f);//把它从已经连接列表中删除,断开连接 f.Close(); } } } catch { } } private void Closing(object sender, EventArgs e)//窗体关闭,断开所有连接,关闭所有线程 { try { foreach (Socket o in conList) { o.Close(); } listenerThread.Abort(); DataThread.Abort(); } catch { } } }}这个例子比较简单,实际在使用中会比较复杂,比如说我们的服务端要实现很多功能,举个网络游戏的例子,你要行走,要攻击,要加血,要回蓝,这每一个动作都对应一个命令,是以命令+内容+结束符的格式传送给服务器的,服务器在接收到信息,再对信息分类处理。下面我看一个这样的例子,是一个FTP的例子。客户端可以显示服务器的文件列表,可以选择要下载的文件,可以上传文件,服务器可以显示客户端的连接IP,可以断开指定的客户端。客户端//Form1.Designer.Csnamespace FTPClientTest{ partial class Form1 { /// summary /// Required designer variable. /// /summary private System.ComponentModel.IContainer components = null; /// summary /// Clean up any resources being used. /// /summary /// param name="disposing"true if managed resources should be disposed; otherwise, false./param protected override void Dispose(bool disposing) { if (disposing && (components != null)) { components.Dispose(); } base.Dispose(disposing); } #region Windows Form Designer generated code /// summary /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// /summary private void InitializeComponent() { this.listBox1 = new System.Windows.Forms.ListBox(); this.button1 = new System.Windows.Forms.Button(); this.button2 = new System.Windows.Forms.Button(); this.button3 = new System.Windows.Forms.Button(); this.button4 = new System.Windows.Forms.Button(); this.button5 = new System.Windows.Forms.Button(); this.SuspendLayout(); // // listBox1 // this.listBox1.FormattingEnabled = true; this.listBox1.ItemHeight = 12; this.listBox1.Location = new System.Drawing.Point(11, 9); this.listBox1.Name = "listBox1"; this.listBox1.Size = new System.Drawing.Size(271, 160); this.listBox1.TabIndex = 0; // // button1 // this