public static bool HasConnection()
{
    try
    {
        System.Net.IPHostEntry i = System.Net.Dns.GetHostEntry("www.google.com");
        return true;
    }
    catch
    {
        return false;
    }
}

工作

多线程版本的ping:

  using System;
  using System.Collections.Generic;
  using System.Diagnostics;
  using System.Net.NetworkInformation;
  using System.Threading;


  namespace OnlineCheck
  {
      class Program
      {

          static bool isOnline = false;

          static void Main(string[] args)
          {
              List<string> ipList = new List<string> {
                  "1.1.1.1", // Bad ip
                  "2.2.2.2",
                  "4.2.2.2",
                  "8.8.8.8",
                  "9.9.9.9",
                  "208.67.222.222",
                  "139.130.4.5"
                  };

              int timeOut = 1000 * 5; // Seconds


              List<Thread> threadList = new List<Thread>();

              foreach (string ip in ipList)
              {

                  Thread threadTest = new Thread(() => IsOnline(ip));
                  threadList.Add(threadTest);
                  threadTest.Start();
              }

              Stopwatch stopwatch = Stopwatch.StartNew();

              while (!isOnline && stopwatch.ElapsedMilliseconds <= timeOut)
              {
                   Thread.Sleep(10); // Cooldown the CPU
              }

              foreach (Thread thread in threadList)
              { 
                  thread.Abort(); // We love threads, don't we?
              }


              Console.WriteLine("Am I online: " + isOnline.ToYesNo());
              Console.ReadKey();
          }

          static bool Ping(string host, int timeout = 3000, int buffer = 32)
          {
              bool result = false;

              try
              {
                  Ping ping = new Ping();                
                  byte[] byteBuffer = new byte[buffer];                
                  PingOptions options = new PingOptions();
                  PingReply reply = ping.Send(host, timeout, byteBuffer, options);
                  result = (reply.Status == IPStatus.Success);
              }
              catch (Exception ex)
              {

              }

              return result;
          }

          static void IsOnline(string host)
          {
              isOnline =  Ping(host) || isOnline;
          }
      }

      public static class BooleanExtensions
      {
          public static string ToYesNo(this bool value)
          {
              return value ? "Yes" : "No";
          }
      }
  }

private bool ping()
{
    System.Net.NetworkInformation.Ping pingSender = new System.Net.NetworkInformation.Ping();
    System.Net.NetworkInformation.PingReply reply = pingSender.Send(address);
    if (reply.Status == System.Net.NetworkInformation.IPStatus.Success)
    {                
        return true;
    }
    else
    {                
        return false;
    }
}

使用NetworkMonitor监控网络状态和internet连接。

示例:

namespace AmRoNetworkMonitor.Demo
{
    using System;

    internal class Program
    {
        private static void Main()
        {
            NetworkMonitor.StateChanged += NetworkMonitor_StateChanged;
            NetworkMonitor.StartMonitor();

            Console.WriteLine("Press any key to stop monitoring.");
            Console.ReadKey();
            NetworkMonitor.StopMonitor();

            Console.WriteLine("Press any key to close program.");
            Console.ReadKey();
        }

        private static void NetworkMonitor_StateChanged(object sender, StateChangeEventArgs e)
        {
            Console.WriteLine(e.IsAvailable ? "Is Available" : "Is Not Available");
        }
    }
}

public static bool CheckForInternetConnection(int timeoutMs = 10000, string url = null)
{
    try
    {
        url ??= CultureInfo.InstalledUICulture switch
        {
            { Name: var n } when n.StartsWith("fa") => // Iran
                "http://www.aparat.com",
            { Name: var n } when n.StartsWith("zh") => // China
                "http://www.baidu.com",
            _ =>
                "http://www.gstatic.com/generate_204",
        };

        var request = (HttpWebRequest)WebRequest.Create(url);
        request.KeepAlive = false;
        request.Timeout = timeoutMs;
        using (var response = (HttpWebResponse)request.GetResponse())
            return true;
    }
    catch
    {
        return false;
    }
}

我在我的3g路由器/调制解调器上的那些方法上有问题，因为如果互联网断开连接，路由器将页面重定向到它的响应页面，所以你仍然得到一个蒸汽，你的代码认为有互联网。 苹果(或其他)有一个热点删除页面，总是返回特定的响应。下面的示例返回“Success”响应。所以你会完全确定你可以连接互联网，并得到真实的回应!

public static bool CheckForInternetConnection()
{
    try
    {       
        using (var webClient = new WebClient())
        using (var stream = webClient.OpenRead("http://captive.apple.com/hotspot-detect.html"))
        {
            if (stream != null)
            {
                //return true;
                stream.ReadTimeout = 1000;
                using (var reader = new StreamReader(stream, Encoding.UTF8, false))
                {
                    string line;
                    while ((line = reader.ReadLine()) != null)
                    {
                        if (line == "<HTML><HEAD><TITLE>Success</TITLE></HEAD><BODY>Success</BODY></HTML>")
                        {
                            return true;
                        }
                        Console.WriteLine(line);
                    }
                }

            }
            return false;
        }
    }
    catch
    {

    }
    return false;
}