Merge pull request #987 from Caliburn-Micro/alert-fix-72

missed if statement

Author: vb2ae

src/Caliburn.Micro.Platform/Platforms/uap/AttachedCollection.81.cs

@@ -1,4 +1,5 @@
-namespace Caliburn.Micro {
+namespace Caliburn.Micro
+{
     using System.Linq;
 
 
@@ -15,69 +16,79 @@
     /// </summary>
     /// <typeparam name="T">The type of item in the attached collection.</typeparam>
     public class AttachedCollection<T> : DependencyObjectCollection, IAttachedObject
-        where T : DependencyObject, IAttachedObject {
+        where T : DependencyObject, IAttachedObject
+    {
         private DependencyObject associatedObject;
 
         /// <summary>
         /// Creates an instance of <see cref="AttachedCollection&lt;T&gt;"/>
         /// </summary>
-        public AttachedCollection() {
+        public AttachedCollection()
+        {
             VectorChanged += OnVectorChanged;
         }
 
         /// <summary>
         /// Attaches the collection.
         /// </summary>
         /// <param name="dependencyObject">The dependency object to attach the collection to.</param>
-        public void Attach(DependencyObject dependencyObject) {
+        public void Attach(DependencyObject dependencyObject)
+        {
             associatedObject = dependencyObject;
             this.OfType<IAttachedObject>().Apply(x => x.Attach(associatedObject));
         }
 
         /// <summary>
         /// Detaches the collection.
         /// </summary>
-        public void Detach() {
+        public void Detach()
+        {
             this.OfType<IAttachedObject>().Apply(x => x.Detach());
             associatedObject = null;
         }
 
         /// <summary>
         /// The currently attached object.
         /// </summary>
-        public DependencyObject AssociatedObject {
+        public DependencyObject AssociatedObject
+        {
             get { return associatedObject; }
         }
 
         /// <summary>
         /// Called when an item is added from the collection.
         /// </summary>
         /// <param name="item">The item that was added.</param>
-        protected virtual void OnItemAdded(DependencyObject item) {
-            if (associatedObject != null) {
-                if (item is IAttachedObject)
-                    ((IAttachedObject) item).Attach(associatedObject);
+        protected virtual void OnItemAdded(DependencyObject item)
+        {
+            if (associatedObject != null && item is IAttachedObject attached)
+            {
+                attached.Attach(associatedObject);
             }
         }
 
         /// <summary>
         /// Called when an item is removed from the collection.
         /// </summary>
         /// <param name="item">The item that was removed.</param>
-        protected virtual void OnItemRemoved(DependencyObject item) {
+        protected virtual void OnItemRemoved(DependencyObject item)
+        {
             var attached = item as IAttachedObject;
-            if (attached != null && attached.AssociatedObject != null) {
+            if (attached != null && attached.AssociatedObject != null)
+            {
                 attached.Detach();
             }
         }
 
-        private void OnVectorChanged(IObservableVector<DependencyObject> sender, IVectorChangedEventArgs @event) {
-            switch (@event.CollectionChange) {
+        private void OnVectorChanged(IObservableVector<DependencyObject> sender, IVectorChangedEventArgs @event)
+        {
+            switch (@event.CollectionChange)
+            {
                 case CollectionChange.ItemInserted:
-                    OnItemAdded(this[(int) @event.Index]);
+                    OnItemAdded(this[(int)@event.Index]);
                     break;
                 case CollectionChange.ItemRemoved:
-                    OnItemRemoved(this[(int) @event.Index]);
+                    OnItemRemoved(this[(int)@event.Index]);
                     break;
                 case CollectionChange.Reset:
                     this.Apply(OnItemRemoved);