iOS Reachability

gistfile1.cs

using MonoTouch.CoreFoundation;
using MonoTouch.SystemConfiguration;
using Xamarin.Forms;
using System;
using WebServices.iOS;
using System.Threading.Tasks;

[assembly:Dependency(typeof(AppleConnectivityServiceImpl))]

namespace WebServices.iOS
{
	public class AppleConnectivityServiceImpl : IConnectivityService
    {
        string currentHostUrl;
        bool reachable = true;
        NetworkReachability remoteHostReachability;
		Action<bool> connectivityChanged;

		public void CreateConnectivityWatchDog (Action<bool> connectivityChanged, string hostUrl)
		{
			this.connectivityChanged = connectivityChanged;

			if (string.IsNullOrWhiteSpace(hostUrl))
			{
				// See "Link-Local-Address": http://en.wikipedia.org/wiki/Link-local_address
				hostUrl = "169.254.0.0";
			}

			if (remoteHostReachability == null || hostUrl != currentHostUrl)
			{
				if (remoteHostReachability != null)
				{
					remoteHostReachability.Unschedule(CFRunLoop.Current, CFRunLoop.ModeDefault);
				}

				// Create new instance if host address changed.
				currentHostUrl = hostUrl;
				
				// Does not work with iOS 8.0.2. Used to work.
				//remoteHostReachability = new NetworkReachability(currentHostUrl); // e.g. "http://www.google.com
				
				// This works:
				remoteHostReachability = new NetworkReachability(new IPAddress(0);)
				
				remoteHostReachability.SetNotification(HandleReachabilityChanged);
				remoteHostReachability.Schedule(CFRunLoop.Current, CFRunLoop.ModeDefault);
			}

			// Trigger callback.
			if (this.connectivityChanged != null)
			{
				this.connectivityChanged (true);
			}
		}


		private void HandleReachabilityChanged(NetworkReachabilityFlags flags)
        {
			Console.WriteLine (flags);
            var requiresConnection = (flags & NetworkReachabilityFlags.ConnectionRequired) > 0;
            // It's reachable if Reachable flag is set and no connection is required.
            reachable = !requiresConnection && (flags & NetworkReachabilityFlags.Reachable) > 0;

			// Trigger callback.
			if (this.connectivityChanged != null)
			{
				this.connectivityChanged (reachable);
			}
        }
    }
}