Modifying Notify Events to Invoke through Threads to avoid possible DeadLocks

Author: ShawnLaMountain

src/ThunderDesign.Net-PCL.Threading/Collections/ObservableCollectionThreadSafe.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
+using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Threading;
 using ThunderDesign.Net.Threading.Extentions;
@@ -16,6 +17,7 @@ public ObservableCollectionThreadSafe(List<T> list) : base(list) { }
         #endregion
 
         #region event handlers
+        public override event NotifyCollectionChangedEventHandler CollectionChanged;
         protected override event PropertyChangedEventHandler PropertyChanged;
         #endregion
 
@@ -198,13 +200,26 @@ public ObservableCollectionThreadSafe(List<T> list) : base(list) { }
 
         public T GetItemByIndex(int index)
         {
-            return this[index];
+            _ReaderWriterLockSlim.EnterReadLock();
+            try
+            {
+                return this[index];
+            }
+            finally
+            {
+                _ReaderWriterLockSlim.ExitReadLock();
+            }
         }
 
         protected override void OnPropertyChanged(PropertyChangedEventArgs e)
         {
             this.NotifyPropertyChanged(PropertyChanged, e.PropertyName);
         }
+
+        protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
+        {
+            this.NotifyCollectionChanged(CollectionChanged, e);
+        }
         #endregion
 
         #region variables

src/ThunderDesign.Net-PCL.Threading/Collections/ObservableDictionaryThreadSafe.cs

@@ -20,6 +20,7 @@ public ObservableDictionaryThreadSafe(IDictionary<TKey, TValue> dictionary, IEqu
         #region event handlers
         public event NotifyCollectionChangedEventHandler CollectionChanged;
         public event PropertyChangedEventHandler PropertyChanged;
+
         #endregion
 
         #region properties
@@ -100,7 +101,6 @@ protected virtual void OnCollectionChanged(NotifyCollectionChangedEventArgs args
         {
             this.NotifyCollectionChanged(CollectionChanged, args);
         }
-
         #endregion
     }
 }

src/ThunderDesign.Net-PCL.Threading/Extentions/INotifyCollectionChangedExtension.cs

@@ -1,4 +1,5 @@
 using System.Collections.Specialized;
+using ThunderDesign.Net.Threading.HelperClasses;
 
 namespace ThunderDesign.Net.Threading.Extentions
 {
@@ -9,9 +10,10 @@ public static void NotifyCollectionChanged(
             NotifyCollectionChangedEventHandler handler,
             NotifyCollectionChangedEventArgs args)
         {
-            //ThreadHelper.RunAndForget(() => handler?.Invoke(sender, args));
+            // Calling 'Invoke' can cause DeadLocks and 'BeginInvoke' can cause System.PlatformNotSupportedException errors so calling Invoke from within a Thread
+            //handler?.Invoke(sender, args);
             //handler?.BeginInvoke(sender, args, ar => { }, null);
-            handler?.Invoke(sender, args);
+            ThreadHelper.RunAndForget(() => handler?.Invoke(sender, args));
         }
     }
 }

src/ThunderDesign.Net-PCL.Threading/Extentions/INotifyPropertyChangedExtension.cs

@@ -1,5 +1,6 @@
 using System.ComponentModel;
 using System.Runtime.CompilerServices;
+using ThunderDesign.Net.Threading.HelperClasses;
 
 namespace ThunderDesign.Net.Threading.Extentions
 {
@@ -19,9 +20,10 @@ public static void NotifyPropertyChanged(
             PropertyChangedEventHandler handler,
             PropertyChangedEventArgs args)
         {
-            //ThreadHelper.RunAndForget(() => handler?.Invoke(sender, args));
+            // Calling 'Invoke' can cause DeadLocks and 'BeginInvoke' can cause System.PlatformNotSupportedException errors so calling Invoke from within a Thread
+            //handler?.Invoke(sender, args);
             //handler?.BeginInvoke(sender, args, ar => { }, null);
-            handler?.Invoke(sender, args);
+            ThreadHelper.RunAndForget(() => handler?.Invoke(sender, args));
         }
 
         public static bool SetProperty<T>(

src/ThunderDesign.Net-PCL.Threading/HelperClasses/ThreadHelper.cs

@@ -33,6 +33,5 @@ public static void RunAndForget(Action action, Action<Exception> handler = null)
                     TaskContinuationOptions.OnlyOnFaulted);
             }
         }
-
     }
 }