* QControlKit.csproj:

* MainPage.xaml.cs:
* AppDelegate.cs:
* QControlKitXamDemo.csproj:
* QCueViewModel.cs:
* QControlKitXamDemo.iOS.csproj:
* QControlKitXamDemo.Android.csproj: Update Packages

* QServer.cs:
* QBrowser.cs:
* QWorkspace.cs:
* QEventArgs.cs:
* QEventHandlers.cs: Refine Server Found/Lost and Workspace
  Added/Removed

QControlKit/QBrowser.cs

@@ -5,61 +5,79 @@ using Serilog;
 
 using QControlKit.Constants;
 using QControlKit.Events;
+using System;
+using System.Collections.Generic;
+using System.Linq;
 
 namespace QControlKit
 {
     public class QBrowser
     {
-
-        ZeroconfResolver.ResolverListener zeroconfTCPBrowser;
-
         public ObservableCollection<QServer> servers = new ObservableCollection<QServer>();
 
         public event QServerFoundHandler ServerFound;
+        public event QServerLostHandler ServerLost;
         public event QServerUpdatedHandler ServerUpdatedWorkspaces;
 
         public QBrowser()
         {
-            zeroconfTCPBrowser = ZeroconfResolver.CreateListener(QBonjour.TCPService);
-            zeroconfTCPBrowser.ServiceFound += ZeroconfHostFound;
-            zeroconfTCPBrowser.ServiceLost += ZeroconfHostLost;
+            ProbeForQLabInstances();
         }
 
-        private void ZeroconfHostLost(object sender, IZeroconfHost e)
+        public async void ProbeForQLabInstances()
         {
-            Log.Information($"[browser] Lost {e.DisplayName} : {e.IPAddress}");
+            IReadOnlyList<IZeroconfHost> results = await
+                    ZeroconfResolver.ResolveAsync(QBonjour.TCPService,TimeSpan.FromSeconds(3));
 
-        }
-
-        private void ZeroconfHostFound(object sender, IZeroconfHost e)
-        {
-            
-            
-            foreach(var service in e.Services)
+            foreach (var zeroconfHost in results)
             {
-                if (service.Key.Equals(QBonjour.TCPService))
+                foreach (var service in zeroconfHost.Services)
                 {
-                    Log.Information($"Found {e.DisplayName} : {e.IPAddress} : {service.Value.Port}");
-
-                    QServer server = serverForAddress(e.IPAddress);
-
-                    if(server == null)
+                    if (service.Key.Equals(QBonjour.TCPService))
                     {
-                        QServer serverToAdd = new QServer(e.IPAddress, service.Value.Port);
-                        serverToAdd.name = e.DisplayName;
-                        serverToAdd.zeroconfHost = e;
-                        servers.Add(serverToAdd);
-                        serverToAdd.refreshWorkspaces();
-                        serverToAdd.ServerUpdated += OnServerUpdatedWorkspace;
-                        OnServerFound(serverToAdd);
-                    }
-                    else
-                    {
-                        server.name = e.DisplayName;
+
+                        QServer server = serverForAddress(zeroconfHost.IPAddress);
+
+                        if (server == null)
+                        {
+                            Log.Information($"[qbrowser] Found {zeroconfHost.DisplayName} : {zeroconfHost.IPAddress} : {service.Value.Port}");
+                            QServer serverToAdd = new QServer(zeroconfHost.IPAddress, service.Value.Port);
+                            serverToAdd.name = zeroconfHost.DisplayName;
+                            serverToAdd.zeroconfHost = zeroconfHost;
+                            servers.Add(serverToAdd);
+                            serverToAdd.refreshWorkspaces();
+                            serverToAdd.ServerUpdated += OnServerUpdatedWorkspace;
+                            OnServerFound(serverToAdd);
+                        }
+                        else
+                        {
+                            server.name = zeroconfHost.DisplayName;
+                            server.refreshWorkspaces();
+                        }
                     }
                 }
             }
 
+            List<QServer> qServers = servers.ToList();
+
+            foreach(var server in qServers)
+            {
+                bool serverToBeRemoved = true;
+                foreach(var zeroconfHost in results){
+                    QServer existingServer = serverForAddress(zeroconfHost.IPAddress);
+                    if(server != null)
+                    {
+                        serverToBeRemoved = false;
+                    }
+                }
+                if (serverToBeRemoved)
+                {
+                    server.disconnect();
+                    servers.Remove(server);
+                    Log.Information($"[qbrowser] Lost {server.name} : {server.host} : {server.port}");
+                    OnServerLost(server);
+                }
+            }
         }
 
         public QServer serverForAddress(string address)
@@ -93,6 +111,11 @@ namespace QControlKit
             ServerFound?.Invoke(this, new QServerFoundArgs { server = server });
         }
 
+        protected virtual void OnServerLost(QServer server)
+        {
+            ServerLost?.Invoke(this, new QServerLostArgs { server = server });
+        }
+
         protected virtual void OnServerUpdatedWorkspace(object source, QServerUpdatedArgs args)
         {
             ServerUpdatedWorkspaces?.Invoke(this, args);
@@ -104,7 +127,6 @@ namespace QControlKit
             {
                 server.disconnect();
             }
-            zeroconfTCPBrowser.Dispose();
         }
     }
 }