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");
        }
    }
}

如果你想在网络/连接发生变化时通知用户/采取行动。 使用NLM API:

https://msdn.microsoft.com/en-us/library/ee264321.aspx http://www.codeproject.com/Articles/34650/How-to-use-the-Windows-NLM-API-to-get-notified-of

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;
    }
}

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;
    }
}

我有三个网络连接测试。

参考系统。Net和system.net.socket 增加以下测试功能:

测试1

public bool IsOnlineTest1()
{
    try
    {
        IPHostEntry dummy = Dns.GetHostEntry("https://www.google.com");
        return true;
    }
    catch (SocketException ex)
    {
        return false;
    }
}

测试2

public bool IsOnlineTest2()
{
    try
    {
        IPHostEntry dummy = Dns.GetHostEntry("https://www.google.com");
        return true;
    }
    catch (SocketException ex)
    {
        return false;
    }
}

测试3

public bool IsOnlineTest3()
{
    System.Net.WebRequest req = System.Net.WebRequest.Create("https://www.google.com");
    System.Net.WebResponse resp = default(System.Net.WebResponse);
    try
    {
        resp = req.GetResponse();
        resp.Close();
        req = null;
        return true;
    }
    catch (Exception ex)
    {
        req = null;
        return false;
    }
}

执行测试

如果您创建了一个名为CheckList的字符串和布尔字典，则可以将每个测试的结果添加到CheckList中。

现在，递归遍历每个KeyValuePair使用for…每一个循环。

如果检查表的值为true，则您知道有Internet连接。

bool bb = System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable();

if (bb == true)
    MessageBox.Show("Internet connections are available");
else
    MessageBox.Show("Internet connections are not available");