Example #1
0
        public static void RemoveHandler(LongLivedViewModel source, EventHandler handler)
        {
            _ = source ?? throw new ArgumentNullException(nameof(source));
            _ = handler ?? throw new ArgumentNullException(nameof(handler));

            CurrentManager.ProtectedRemoveHandler(source, handler);
        }
Example #2
0
        private void ToggleEventHandlingMechanism(object sender, RoutedEventArgs e)
        {
            _longLivedViewModel   = new LongLivedViewModel();
            _testWeakEventManager = (EventPattern)((int)(_testWeakEventManager + 1) % 3);

            DataContext = _longLivedViewModel;

            TestWeakEventManager(_longLivedViewModel);
        }
Example #3
0
        public void ShortLivedViewModel_CustomWeakEventManagerReferenceToLongLivedViewModel_HandlesEventRaisedOnLongLivedViewModel()
        {
            var longLivedViewModel  = new LongLivedViewModel();
            var shortLivedViewModel = new ShortLivedViewModel(longLivedViewModel, EventPattern.CustomEventManager);

            // act
            longLivedViewModel.RaiseEvent();

            Assert.AreEqual("ShortLivedViewModel - handled event", longLivedViewModel.Log);
        }
Example #4
0
        ShortLivedViewModel_StrongReferenceToLongLivedViewModel_ShortLivedViewModelUnreferenced_AttemptGarbageCollection_ShortLivedViewModelKeptAliveByStrongReference_HandlesEventRaisedOnLongLivedViewModel()
        {
            var longLivedViewModel  = new LongLivedViewModel();
            var shortLivedViewModel = new ShortLivedViewModel(longLivedViewModel, EventPattern.StrongReference);

            shortLivedViewModel = null;
            GC.Collect();

            // act
            longLivedViewModel.RaiseEvent();

            Assert.AreEqual("ShortLivedViewModel - handled event", longLivedViewModel.Log);
        }
Example #5
0
        ShortLivedViewModel_CustomWeakEventManagerReferenceToLongLivedViewModel_ShortLivedViewModelUnreferenced_AttemptGarbageCollection_ShortLivedViewModelGarbageCollected()
        {
            var longLivedViewModel  = new LongLivedViewModel();
            var shortLivedViewModel = new ShortLivedViewModel(longLivedViewModel, EventPattern.CustomEventManager);
            var weakReferenceShortLivedViewModel = new WeakReference(shortLivedViewModel);

            shortLivedViewModel = null;

            // act
            GC.Collect();

            Assert.IsFalse(weakReferenceShortLivedViewModel.IsAlive);
        }
Example #6
0
        ShortLivedViewModel_StrongReferenceToLongLivedViewModel_ShortLivedViewModelUnreferenced_AttemptGarbageCollection_ShortLivedViewModelKeptAliveByStrongReference()
        {
            var longLivedViewModel  = new LongLivedViewModel();
            var shortLivedViewModel = new ShortLivedViewModel(longLivedViewModel, EventPattern.StrongReference);
            var weakReferenceShortLivedViewModel = new WeakReference(shortLivedViewModel);

            shortLivedViewModel = null;

            // act
            GC.Collect();

            Assert.IsTrue(weakReferenceShortLivedViewModel.IsAlive);
        }
Example #7
0
        ShortLivedViewModel_CustomWeakEventManagerReferenceToLongLivedViewModel_ShortLivedViewModelUnreferenced_AttemptGarbageCollection_ShortLivedViewModelGarbageCollected_DoesNotHandleEventRaisedOnLongLivedViewModel()
        {
            var longLivedViewModel  = new LongLivedViewModel();
            var shortLivedViewModel = new ShortLivedViewModel(longLivedViewModel, EventPattern.CustomEventManager);

            shortLivedViewModel = null;
            GC.Collect();

            // act
            longLivedViewModel.RaiseEvent();

            Assert.IsEmpty(longLivedViewModel.Log);
        }
Example #8
0
        private void TestWeakEventManager(LongLivedViewModel longLivedViewModel)
        {
            switch (_testWeakEventManager)
            {
            case EventPattern.StrongReference:
                longLivedViewModel.Log = "Using strong reference";
                break;

            case EventPattern.GenericWeakEventManager:
                longLivedViewModel.Log = "Using generic WeakEventManager";
                break;

            case EventPattern.CustomEventManager:
                longLivedViewModel.Log = "Using custom WeakEventManager";
                break;
            }

            var shortLivedViewModel = new ShortLivedViewModel(longLivedViewModel, _testWeakEventManager);
            var weakReferenceShortLivedViewModel = new WeakReference(shortLivedViewModel);

            longLivedViewModel.Log = "Raise event on LongLivedViewModel";
            // expect shortLivedViewModel to handle event
            longLivedViewModel.RaiseEvent();

            longLivedViewModel.Log = "Clear reference to ShortLivedViewModel";

            shortLivedViewModel = null;

            longLivedViewModel.Log = "Force garbage collection";
            GC.Collect();

            longLivedViewModel.Log = $"ShortLivedViewModel.IsAlive = {weakReferenceShortLivedViewModel.IsAlive}";

            longLivedViewModel.Log = "Raise event on LongLivedViewModel";
            // shortLivedViewModel will only handle the event if not using the WeakEventManager
            longLivedViewModel.RaiseEvent();
        }