一段扫描端口的代码，希望高人帮我改一个小bug

Question

问题描述，加断点调试，openPort有值，但直接运行openPort就为空了。这是怎么回事啊
C# codestatic List<string> openPort=new List<string>();
string scanPort="";
static void Main(string[] args)  
        {  
           
           
            Scan(ip, startPort, endPort);   //端口扫描   
               for(int i=0;i<openPort.Count;i++)
               {
                  scanPort++;
               }
             
        }   static void Scan(IPAddress ip, int startPort, int endPort)  
        {  
            Random rand = new Random((int)DateTime.Now.Ticks);  
            Console.WriteLine("Begin Scan...");  
            for (int port = startPort; port < endPort; port++)  
            {  
                Socket scanSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);  
                //寻找一个未使用的端口进行绑定   
                do  
                {  
                    try  
                    {  
                        scanSocket.Bind(new IPEndPoint(IPAddress.Any, rand.Next(65535)));  
                        break;  
                    }  
                    catch  
                    {   
                        //绑定失败   
                    }  
                } while (true);  
                 
                try  
                {  
                    scanSocket.BeginConnect(new IPEndPoint(ip, port), ScanCallBack, new ArrayList() { scanSocket, port});  
                }  
                catch  
                {  
                   
                    continue;  
                }  
                
            }  
  
            Console.WriteLine("Port Scan Completed!");  
        }  
  
        /// <summary>   
        /// BeginConnect的回调函数   
        /// </summary>   
        /// <param name="result">异步Connect的结果</param>   
        static void ScanCallBack(IAsyncResult result)  
        {  
            //解析 回调函数输入 参数   
            ArrayList arrList = (ArrayList)result.AsyncState;  
            Socket scanSocket = (Socket)arrList[0];  
            int port = (int)arrList[1];  
            //判断端口是否开放   
            if (result.IsCompleted && scanSocket.Connected)  
            {  
               openPort.Add("port {0,5}\tOpen.", port);  
            }  
            else  
            {  
                openPort.Add("port {0,5}\tClosed.", port);    
            }  
            //关闭套接字   
            scanSocket.Close();  
        }  

Answer 1

啥意思， openPort不是个变量吗，怎么叫运行 openPort

Answer 2

using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Sockets;
using System.Collections;namespace Test
{    public class Demo
    {
        static List<string> openPort = new List<string>();
        string scanPort = "";        static void Main(string[] args)
        {
            IPAddress ip = IPAddress.Parse("192.168.1.68");
            Int32 scanPort = 0;            Scan(ip, UInt16.MinValue, UInt16.MaxValue,1000);   //端口扫描   
            for (int i = 0; i < openPort.Count; i++)
            {
                scanPort++;
            }
        }        static void Scan(IPAddress ip, UInt16 startPort, UInt16 endPort, UInt16 maxCount)
        {
            Random rand = new Random((int)DateTime.Now.Ticks);
            Console.WriteLine("Begin Scan...");
            for (int port = startPort; port < endPort; port++)
            {
                Socket scanSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
                //寻找一个未使用的端口进行绑定   
                do
                {
                    try
                    {
                        scanSocket.Bind(new IPEndPoint(IPAddress.Any, rand.Next(65535)));
                        break;
                    }
                    catch
                    {
                        //绑定失败   
                    }
                } while (true);                try
                {
                    scanSocket.BeginConnect(new IPEndPoint(ip, port), ScanCallBack, new ArrayList() { scanSocket, port });
                }
                catch
                {
                    continue;
                }                if (openPort.Count >= maxCount)
                {
                    return;
                }
            }            Console.WriteLine("Port Scan Completed!");
        }        /// <summary>   
        /// BeginConnect的回调函数   
        /// </summary>   
        /// <param name="result">异步Connect的结果</param>   
        static void ScanCallBack(IAsyncResult result)
        {
            //解析 回调函数输入 参数   
            ArrayList arrList = (ArrayList)result.AsyncState;
            Socket scanSocket = (Socket)arrList[0];
            int port = (int)arrList[1];
            //判断端口是否开放   
            if (result.IsCompleted && scanSocket.Connected)
            {
                openPort.Add(String.Format("port {0,5}\tOpen.", port));
            }
            else
            {
                openPort.Add(String.Format("port {0,5}\tClosed.", port));
            }
            //关闭套接字   
            scanSocket.Close();        }
    }
}

Answer 3

就是直接运行项目   ，openPort取不到值

Answer 4

 带Main(string[] args)参数的用vs直接启动是取不到值。编译成exe然后在控制台里运行并输入参数。

Answer 5

string scanPort="";static void Main(string[] args)  
{  
     Scan(ip, startPort, endPort);   //端口扫描   
     for(int i=0;i<openPort.Count;i++)
    {
        scanPort++;    }
} 
上面你的代码中scanPort不是定义为一个string变量么，怎么你在下面这里把它进行++操作呢？没看懂

Answer 6

如果我把方法写到一个类中呢，然后在Main函数下调用可以吗