一个问题,请大家一起讨论下哈!

Question

我想在WEB下实现网段的扫描:
比如:我输入192.168.1.2---192.168.3.254(跨网段)
然后开启多线程把存在的IP地址在指定文本框中显示出来.
问了几个朋友说很难实现!!!
请问:要用到何种技术实现?应该注意什么问题?
如果能提供相关源代码必送分!

Answer 1

using System.Net;
using System.Net.Sockets;
using System.Threading;        private void Form1_Load(object sender, EventArgs e)
        {
            Control.CheckForIllegalCrossThreadCalls = false;
        }        private void button1_Click(object sender, EventArgs e)
        {
            Thread t = new Thread(new ThreadStart(iptest));
            t.IsBackground = true;
            t.Start();
        }        private void iptest()
        {
            string[] startip = textBox1.Text.Split(new char[] { '.' });
            string[] endip = textBox2.Text.Split(new char[] { '.' });
            string changeip = startip[2];
            string endchangeip = endip[2];
            string lastip = startip[3];
            string endlastip = endip[3];
            for (int i = Convert.ToInt32(changeip); i <= Convert.ToInt32(endchangeip); i++)
            {
                if (i != Convert.ToInt32(endchangeip))
                {
                    for (int m = Convert.ToInt32(lastip); m < 255; m++)
                    {
                        try
                        {
                            string testip = startip[0] + "." + startip[1] + "." + i.ToString() + "." + m.ToString();
                            IPAddress ip = IPAddress.Parse(testip);
                            IPHostEntry iphost = Dns.GetHostByAddress(ip);
                            if (iphost.HostName != null && iphost.HostName != "")
                            {
                                listBox1.Items.Add(iphost.HostName);
                                Application.DoEvents();
                            }
                        }
                        catch
                        { }
                    }
                }
                else
                {
                    for (int j = 0; j <= Convert.ToInt32(endchangeip); j++)
                    {
                        try
                        {
                            string testip = startip[0] + "." + startip[1] + "." + i.ToString() + "." + j.ToString();
                            IPAddress ip = IPAddress.Parse(testip);
                            IPHostEntry iphost = Dns.GetHostByAddress(ip);
                            if (iphost.HostName != null && iphost.HostName != "")
                            {
                                listBox1.Items.Add(iphost.HostName);
                            }
                        }
                        catch 
                        { }
                    }
                }            }
        }
根据输入的地址如果能得到返回的主机名说明主机存活，
据说用socket地址+端口可以扫描所有的端口，

Answer 2

注意:
我是在WEB 下实现 ,不是 WIN应用程序下实现.....