Activated event handler must be async in Caliburn.Micro 5

Author: abparticular

src/ServiceControl.Config/Framework/Rx/RxScreen.cs

@@ -37,7 +37,7 @@ public class RxScreen : RxViewAware, IScreen, IChild, IModalResult
         /// <summary>
         /// Raised after activation occurs.
         /// </summary>
-        public event EventHandler<ActivationEventArgs> Activated = (sender, e) => { };
+        public event AsyncEventHandler<ActivationEventArgs> Activated = (sender, e) => Task.CompletedTask;
 
         public IEventAggregator EventAggregator { get; set; }
 
@@ -70,7 +70,7 @@ async Task IActivate.ActivateAsync(CancellationToken cancellationToken)
             Log.Info("Activating {0}.", this);
             await OnActivate();
 
-            Activated(this, new ActivationEventArgs
+            await Activated(this, new ActivationEventArgs
             {
                 WasInitialized = initialized
             });

src/ServiceControl.Config/Framework/Rx/RxViewAware.cs

@@ -2,6 +2,7 @@
 {
     using System;
     using System.Collections.Generic;
+    using System.Threading.Tasks;
     using Caliburn.Micro;
 
     public class RxViewAware : RxPropertyChanged, IViewAware
@@ -61,7 +62,7 @@ public virtual object GetView(object context = null)
         static void AttachViewReadyOnActivated(IActivate activatable, object nonGeneratedView)
         {
             var viewReference = new WeakReference(nonGeneratedView);
-            EventHandler<ActivationEventArgs> handler = null;
+            AsyncEventHandler<ActivationEventArgs> handler = null;
             handler = (s, e) =>
             {
                 ((IActivate)s).Activated -= handler;
@@ -70,6 +71,8 @@ static void AttachViewReadyOnActivated(IActivate activatable, object nonGenerate
                 {
                     PlatformProvider.Current.ExecuteOnLayoutUpdated(view, ((RxViewAware)s).OnViewReady);
                 }
+
+                return Task.CompletedTask;
             };
             activatable.Activated += handler;
         }