Program.cs

using System;
using System.Diagnostics;
using System.Threading;
using System.Net.NetworkInformation;
using nanoFramework.Runtime.Native;
using Windows.Devices.Gpio;

namespace WiFiAP
{
    public class Program
    {
        // Start Simple WebServer
        static WebServer server = new WebServer();

        // Connected Station count
        static int connectedCount = 0;

        // GPIO pin used to put device into AP set-up mode
        const int SETUP_PIN = 5;

        public static void Main()
        {
            Debug.WriteLine("Welcome to WiFI Soft AP world!");

            GpioPin setupButton = GpioController.GetDefault().OpenPin(SETUP_PIN);
            setupButton.SetDriveMode(GpioPinDriveMode.InputPullUp);

            // If Wireless station is not enabled then start Soft AP to allow Wireless configuration
            // or Button pressed
            if (!Wireless80211.IsEnabled() || (setupButton.Read() == GpioPinValue.Low))
            {
                Wireless80211.Disable();

                if (WirelessAP.Setup() == false)
                {
                    // Reboot device to Activate Access Point on restart
                    Debug.WriteLine($"Setup Soft AP, Rebooting device");
                    Power.RebootDevice();
                }

                Debug.WriteLine($"Running Soft AP, waiting for client to connect");
                Debug.WriteLine($"Soft AP IP address :{WirelessAP.GetIP()}");

                // Link up Network event to show Stations connecting/disconnecting to Access point.
                NetworkChange.NetworkAPStationChanged += NetworkChange_NetworkAPStationChanged; ;
            }
            else
            {
                Debug.WriteLine($"Running in normal mode, connecting to Access point");
                string IpAdr = Wireless80211.WaitIP();
                Debug.WriteLine($"Connected as {IpAdr}");
            }


            // Just wait for now
            // Here you would have the reset of your program using the client WiFI link
            Thread.Sleep(Timeout.Infinite);
        }

        /// <summary>
        /// Event handler for Stations connecting or Disconnecting
        /// </summary>
        /// <param name="NetworkIndex">The index of Network Interface raising event</param>
        /// <param name="e">Event argument</param>
        private static void NetworkChange_NetworkAPStationChanged(int NetworkIndex, NetworkAPStationEventArgs e)
        {
            Debug.WriteLine($"NetworkAPStationChanged event Index:{NetworkIndex} Connected:{e.IsConnected} Station:{e.StationIndex} ");

            // if connected then get information on the connecting station 
            if (e.IsConnected)
            {
                WirelessAPConfiguration wapconf = WirelessAPConfiguration.GetAllWirelessAPConfigurations()[0];
                WirelessAPStation station = wapconf.GetConnectedStations(e.StationIndex);

                string macString = BitConverter.ToString(station.MacAddres);
                Debug.WriteLine($"Station mac {macString} Rssi:{station.Rssi} PhyMode:{station.PhyModes} ");

                connectedCount++;

                // Start web server when it connects otherwise the bind to network will fail as 
                // no connected network. Start web server when first station connects 
                if (connectedCount == 1)
                {
                    // Wait for Station to be fully connected before starting web server
                    // other you will get a Network error
                    Thread.Sleep(2000); 
                    server.Start();
                }
                }
            else
            {
                // Station disconnected. When no more station connected then stop web server
                if (connectedCount > 0)
                {
                    connectedCount--;
                    if (connectedCount == 0)
                        server.Stop();
                }
            }

        }
    }
}