C# 获取本机可用端口

System.Net.NetworkInformation命名空间下提供IPGlobalProperties类，用来提供本地计算机有关的网络连接信息，获取本机可用端口的使用方式如下：

using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.NetworkInformation;
using System.Linq;

namespace Common
{
    public class AvailablePort
    {
        private const int MaxPort= 65535;

        /// <summary>
        /// 获取所有可用的TCP端口
        /// </summary>
        /// <param name="startPort"></param>
        /// <returns></returns>
        public static List<int> GetAllAvailableTCPPort(int startPort = 1000)
        {
            //提供本地计算机有关网络连接信息
            IPGlobalProperties iPGlobalProperties = IPGlobalProperties.GetIPGlobalProperties();
            //获取可用的TCP监听终结点信息
            IPEndPoint[] iPEndPoints = iPGlobalProperties.GetActiveTcpListeners();
            return iPEndPoints.Where(q => q.Port >= startPort && q.Port <= MaxPort).Select(q => q.Port).ToList();
        }

        /// <summary>
        /// 获取所有可用的UDP端口
        /// </summary>
        /// <param name="startPort"></param>
        /// <returns></returns>
        public static List<int> GetAllAvailableUDPPort(int startPort = 1000)        {
            //提供本地计算机有关网络连接信息
            IPGlobalProperties iPGlobalProperties = IPGlobalProperties.GetIPGlobalProperties();
            //获取可用的UDP监听终结点信息
            IPEndPoint[] iPEndPoints = iPGlobalProperties.GetActiveUdpListeners();
            return iPEndPoints.Where(q => q.Port >= startPort && q.Port <= MaxPort).Select(q => q.Port).ToList();
        }

        /// <summary>
        /// 获取所有TCP连接
        /// </summary>
        /// <param name="startPort"></param>
        /// <returns></returns>
        public static void GetAllTCPConnect(int startPort = 1000)
        {
            //提供本地计算机有关网络连接信息
            IPGlobalProperties iPGlobalProperties = IPGlobalProperties.GetIPGlobalProperties();
            //获取TCP连接信息
            TcpConnectionInformation[] iPEndPoints = iPGlobalProperties.GetActiveTcpConnections();
            foreach (var item in iPEndPoints)
            {
                Console.WriteLine($"Local:{item.LocalEndPoint.Address},Remote:{item.RemoteEndPoint.Address},State:{item.State}");
            }
        }
    }
}