自己写的端口扫描程序

在开始研究编程之前，我想当一名黑客，很羡慕那些牛人写的那些端口扫描工具，比如x-scan，我当时就想，这种厉害的程序是怎么写出来的呢？后来开始研究编程了，先是用的vb，vb开始有了一定的研究以后，就写了一个端口扫描工具，但是占用的系统资源超大，每次运行的时候cpu使用率都是100，很恐怖，也变相的否定了我的程序，现在一直研究c#，虽然没有达到精通的程度，但是也可以自己写一些自己需要的工具了，于是又想写一个端口扫描工具，而且也真的写了出来。虽然说现在的端口扫描工具已经有很多了，而且好的也不少，但是自己写就是想圆自己原来的梦想，就写了这么一个。每次看到这个程序，就会想起原来的那些日子，呵呵 原来已经走过来了，但是仍然是无法忘记的。这个程序的开发环境是.net2005，也就是.net2.0，程序有点简陋。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.Threading;
namespace WindowsApplication5
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void button3_Click(object sender, EventArgs e)
{
AboutBox1 myabout = new AboutBox1();
myabout.Show();

}

private void textBox4_TextChanged(object sender, EventArgs e)
{

}
IPAddress ipRemote;
int startport;
int endport;
int a;
int b;
int nowport;
TcpClient tc;

string myhost;
Thread startscan;
bool localscan = false;

//TimeSpan d1 = DateTime.Now.TimeOfDay;

private void scan()
{
textBox1.ReadOnly = true;
button1.Enabled = false;
int progmax = b - a + 1; //设置进度条的范围
int pvalue = 0;
this.progress1.Maximum = progmax;

this.progress1.Value = pvalue;
for (nowport = a; nowport <=endport; nowport++)
{
tc = new TcpClient();

tc.SendTimeout = tc.ReceiveTimeout = 2000;
//nowport = a;
try
{
//tc = new TcpClient();

//tc.SendTimeout = tc.ReceiveTimeout = 1000;

if (checkBox1.Checked)
{
tc.Connect(myhost, nowport);
}
else
{
tc.Connect(ipRemote, nowport);
}
if (tc.Connected)
{

this.listBox1.Items.Add(nowport.ToString() + " is open");
//label4.Text = nowport.ToString();
listBox1.Refresh();

}

}
catch
{
//容错处理

this.listBox1.Items.Add(nowport.ToString() + " is closed");
//label4.Text = nowport.ToString();
listBox1.Refresh();

}
finally
{
tc.Close();
tc = null;
label4.Text = nowport.ToString();
pvalue++;
progress1.Value = pvalue;
//Thread.Sleep(10);
}

}

textBox1.ReadOnly = false;
if (checkBox1.Checked)
{
localscan = true;
}
else
{
localscan = false;
}
checkBox1.Enabled = true;
button1.Enabled = true;
this.label4.Text = "";

startscan.Abort();

}
private void button1_Click(object sender, EventArgs e)
{
if (checkBox1.Checked)
{
textBox1.Text = textBox1.Text;
textBox4.Text = "Now scan:" + textBox1.Text;
checkBox1.Enabled = false;
}
else
{
try
{

ipRemote = IPAddress.Parse(textBox1.Text);

}

catch //判断给定的IP地址的合法性
{

MessageBox.Show("输入的IP地址不合法！", "错误！");

return;

}
}
try//判断端口是否合法
{
startport = int.Parse(textBox2.Text);
endport = int.Parse(textBox3.Text);
}
catch
{
MessageBox.Show("请输入合法的数字","错误！");
return;
}
if (startport < 1 | startport > 65536 | endport<1 | endport >65535)
{
MessageBox.Show("windows的端口在1-65535之间","错误！");
}
if (endport < startport)
{
a = endport;
b = startport;

}
else
{
a = startport;
b = endport;
}
//创建扫描线程
startscan = new Thread(new ThreadStart(scan));
startscan.Start();

}

private void Form1_Load(object sender, EventArgs e)
{

this.textBox1.Text = "192.168.2.5";

//this.button2.Enabled = false;

}

private void button4_Click(object sender, EventArgs e)
{

listBox1.Items.Clear();
textBox4.Clear();
}

private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
if (this.checkBox1.Checked)
{
myhost = Dns.GetHostName();
textBox1.Text = myhost;
textBox1.ReadOnly = true;

}
else {
textBox1.ReadOnly = false;
textBox1.Text = "";
}

}

private void button2_Click(object sender, EventArgs e)
{
try
{
startscan.Abort();
textBox1.ReadOnly = false;
if (checkBox1.Checked)
{
localscan = true;
}
else
{
localscan = false;
}
this.label4.Text = "";
checkBox1.Enabled = true;
button1.Enabled = true;

}
catch
{
MessageBox.Show("扫描线程还没有启动","错误！");
}

}

private void groupBox2_Enter(object sender, EventArgs e)
{

}

private void groupBox1_Enter(object sender, EventArgs e)
{

}
}
}