Fixing issues with DynamicResource usage

Author: batzen

src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/ResourceDictionary.cs

@@ -109,7 +109,7 @@ private void CopyToWithoutLock(DictionaryEntry[] array, int arrayIndex)
                 entry.Value = value; // refresh the entry value in case it was changed in the previous call
             }
         }
-        
+
         // This is set when the RD is loaded from unsafe xps doc. This will be checked while creating reader for RD source.
         internal bool IsUnsafe { get; set; }
 
@@ -157,7 +157,7 @@ public Uri Source
                 // that it is being passed down by the Baml parsing code, and it is trying to give us more
                 // information to avoid possible ambiguities in assembly resolving. Use the VersionedUri
                 // to resolve, and the set _source to the OriginalUri so we don't change the return of Source property.
-                // The versioned Uri is not stored, if the version info is needed while debugging, once this method 
+                // The versioned Uri is not stored, if the version info is needed while debugging, once this method
                 // returns _reader should be set, from there BamlSchemaContext.LocalAssembly contains the version info.
                 if (uriWrapper == null)
                 {
@@ -169,10 +169,10 @@ public Uri Source
                     _source = uriWrapper.OriginalUri;
                     sourceUri = uriWrapper.VersionedUri;
                 }
-                
+
                 Clear();
-                
-                
+
+
                 Uri uri = BindUriHelper.GetResolvedUri(_baseUri, sourceUri);
 
                 WebRequest request = WpfWebRequestHelper.CreateRequest(uri);
@@ -1737,10 +1737,7 @@ private object FetchResource(
                     {
                         // Cache the deferredResourceReference so that it can be validated
                         // in case of a dictionary change prior to its inflation
-                        if (_deferredResourceReferences == null)
-                        {
-                            _deferredResourceReferences = new DeferredResourceReferenceList();
-                        }
+                        _deferredResourceReferences ??= new DeferredResourceReferenceList();
 
                         if (_deferredResourceReferences.Get(resourceKey) is { } existingDeferredResourceReference
                             && existingDeferredResourceReference.Dictionary == this)
@@ -1749,14 +1746,7 @@ private object FetchResource(
                         }
                         else
                         {
-                            if (_ownerApps != null)
-                            {
-                                deferredResourceReference = new DeferredAppResourceReference(this, resourceKey);
-                            }
-                            else
-                            {
-                                deferredResourceReference = new DeferredResourceReference(this, resourceKey);
-                            }
+                            deferredResourceReference = _ownerApps is not null ? new DeferredAppResourceReference(this, resourceKey) : new DeferredResourceReference(this, resourceKey);
 
                             _deferredResourceReferences.AddOrSet(deferredResourceReference);
                         }
@@ -1781,10 +1771,29 @@ private object FetchResource(
         /// </summary>
         private void ValidateDeferredResourceReferences(object resourceKey)
         {
-            if (_deferredResourceReferences != null)
+            if (_deferredResourceReferences is null)
+            {
+                return;
+            }
+
+            if (resourceKey is null)
+            {
+                foreach (DeferredResourceReference deferredResourceReference in _deferredResourceReferences)
+                {
+                    Inflate(deferredResourceReference);
+                }
+            }
+            else
             {
                 DeferredResourceReference deferredResourceReference = _deferredResourceReferences.Get(resourceKey);
 
+                Inflate(deferredResourceReference);
+            }
+
+            return;
+
+            void Inflate(DeferredResourceReference deferredResourceReference)
+            {
                 if (deferredResourceReference is not null)
                 {
                     // This will inflate the deferred reference, causing it
@@ -2504,9 +2513,9 @@ private enum PrivateFlags : byte
 
         /// <summary>
         /// This wrapper class exists so SourceUriTypeConverterMarkupExtension can pass
-        /// a more complete Uri to help resolve to the correct assembly, while also passing 
+        /// a more complete Uri to help resolve to the correct assembly, while also passing
         /// the original Uri so that ResourceDictionary.Source still returns the original value.
-        /// </summary> 
+        /// </summary>
         internal class ResourceDictionarySourceUriWrapper : Uri
         {
             public ResourceDictionarySourceUriWrapper(Uri originalUri, Uri versionedUri) : base(originalUri.OriginalString, UriKind.RelativeOrAbsolute)

src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/ResourceReferenceExpression.cs

@@ -278,7 +278,10 @@ private void InvalidateCacheValue()
                     }
                 }
 
-                deferredResourceReference.RemoveFromDictionary();
+                // This will inflate the deferred reference, causing it
+                // to be removed from the list.  The list may also be
+                // purged of dead references.
+                deferredResourceReference.GetValue(BaseValueSourceInternal.Unknown);
             }
 
             StopListeningForFreezableChanges(resource);
@@ -341,8 +344,8 @@ private void InvalidateMentorCache()
         internal void InvalidateExpressionValue(object sender, EventArgs e)
         {
             // VS has a scenario where a TreeWalk invalidates all reference expressions on a DependencyObject.
-            // If there is a dependency between RRE's, 
-            // invalidating one RRE could cause _targetObject to be null on the other RRE. Hence this check. 
+            // If there is a dependency between RRE's,
+            // invalidating one RRE could cause _targetObject to be null on the other RRE. Hence this check.
             if (_targetObject == null)
             {
                 return;
@@ -404,7 +407,7 @@ private void ListenForFreezableChanges(object resource)
                     {
                         _weakContainerRRE = new ResourceReferenceExpressionWeakContainer(this);
                     }
-                    
+
                     // Hook up the event to the weak container to prevent memory leaks (Bug436021)
                     _weakContainerRRE.AddChangedHandler(resourceAsFreezable);
                     WriteInternalState(InternalState.IsListeningForFreezableChanges, true);
@@ -435,7 +438,7 @@ private void StopListeningForFreezableChanges(object resource)
                     }
                 }
 
-                // It is possible that a freezable was unfrozen during the call to ListForFreezableChanges 
+                // It is possible that a freezable was unfrozen during the call to ListForFreezableChanges
                 // but was frozen before the call to StopListeningForFreezableChanges
                 WriteInternalState(InternalState.IsListeningForFreezableChanges, false);
             }
@@ -512,8 +515,8 @@ private enum InternalState : byte
         #region ResourceReferenceExpressionWeakContainer
 
         /// <summary>
-        /// ResourceReferenceExpressionWeakContainer handles the Freezable.Changed event 
-        /// without holding a strong reference to ResourceReferenceExpression. 
+        /// ResourceReferenceExpressionWeakContainer handles the Freezable.Changed event
+        /// without holding a strong reference to ResourceReferenceExpression.
         /// </summary>
         private class ResourceReferenceExpressionWeakContainer : WeakReference
         {
@@ -542,7 +545,7 @@ public void AddChangedHandler(Freezable resource)
                 }
 
                 _resource = resource;
-            
+
                 Debug.Assert(!_resource.IsFrozen);
                 _resource.Changed += new EventHandler(this.InvalidateTargetSubProperty);
             }
@@ -558,7 +561,7 @@ public void RemoveChangedHandler()
 
             private Freezable _resource;
         }
-        #endregion 
+        #endregion
     }
 
     /// <summary>

src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/SystemResources.cs

@@ -1412,7 +1412,7 @@ private static IntPtr SystemThemeFilterMessage(IntPtr hwnd, int msg, IntPtr wPar
                     }
 
                     SystemParameters.InvalidateWindowFrameThicknessProperties();
-                    
+
                     if(ThemeManager.IsFluentThemeEnabled)
                     {
                         ThemeManager.ApplySystemTheme();
@@ -1733,8 +1733,7 @@ internal override object GetValue(BaseValueSourceInternal valueSource)
             // the dictionary else just retun the cached value
             if (_dictionary != null)
             {
-                bool canCache;
-                object value  = _dictionary.GetValue(_keyOrValue, out canCache);
+                object value  = _dictionary.GetValue(_keyOrValue, out bool canCache);
                 if (canCache)
                 {
                     // Note that we are replacing the _keyorValue field
@@ -1790,8 +1789,7 @@ internal override Type GetValueType()
             {
                 // Take a peek at the element type of the ElementStartRecord
                 // within the ResourceDictionary's deferred content.
-                bool found;
-                return _dictionary.GetValueType(_keyOrValue, out found);
+                return _dictionary.GetValueType(_keyOrValue, out bool _);
             }
             else
             {
@@ -1800,7 +1798,7 @@ internal override Type GetValueType()
         }
 
         // remove this DeferredResourceReference from its ResourceDictionary
-        internal virtual void RemoveFromDictionary()
+        protected virtual void RemoveFromDictionary()
         {
             if (_dictionary != null)
             {
@@ -1970,7 +1968,7 @@ internal override Type GetValueType()
         }
 
         // remove this DeferredResourceReference from its ResourceDictionary
-        internal override void RemoveFromDictionary()
+        protected override void RemoveFromDictionary()
         {
             // DeferredThemeResourceReferences are never added to the dictionary's
             // list of deferred references, so they don't need to be removed.
@@ -2034,11 +2032,11 @@ internal override bool IsUnset
         #endregion Properties
     }
 
-    internal class DeferredResourceReferenceList
+    internal class DeferredResourceReferenceList : IEnumerable<DeferredResourceReference>
     {
         private readonly object _syncRoot = new();
         private readonly Dictionary<object, WeakReference<DeferredResourceReference>> _entries = new();
-        private int _potentiallyDeadEntryCount = 0;
+        private int _potentiallyDeadEntryCount;
 
         public void AddOrSet(DeferredResourceReference deferredResourceReference)
         {
@@ -2111,6 +2109,11 @@ private void PurgeIfRequired()
         }
 
         private void Purge()
+        {
+            Purge(null);
+        }
+
+        private void Purge(List<DeferredResourceReference> aliveItems)
         {
             lock (_syncRoot)
             {
@@ -2119,10 +2122,14 @@ private void Purge()
 
                 foreach (KeyValuePair<object, WeakReference<DeferredResourceReference>> entry in _entries)
                 {
-                    if (entry.Value.TryGetTarget(out _) == false)
+                    if (entry.Value.TryGetTarget(out var item) is false)
                     {
                         deadKeys.Add(entry.Key);
                     }
+                    else
+                    {
+                        aliveItems?.Add(item);
+                    }
                 }
 
                 foreach (object deadKey in deadKeys)
@@ -2131,5 +2138,17 @@ private void Purge()
                 }
             }
         }
+
+        public IEnumerator<DeferredResourceReference> GetEnumerator()
+        {
+            var aliveItems = new List<DeferredResourceReference>(_entries.Count);
+            Purge(aliveItems);
+            return aliveItems.GetEnumerator();
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return GetEnumerator();
+        }
     }
 }

src/Microsoft.DotNet.Wpf/src/WindowsBase/System/Windows/DependencyObject.cs

@@ -863,7 +863,7 @@ internal bool ProvideSelfAsInheritanceContext( DependencyObject doValue, Depende
             // on side-effects from setting the "Freezable context".  Freezable's
             // implementation does its own checks of the conditions omitted here.
             // Enhancement suggestion: Freezable should follow the same rules for
-            // InheritanceContext as everyone else 
+            // InheritanceContext as everyone else
 
 
             if (doValue != null &&
@@ -910,7 +910,7 @@ internal bool RemoveSelfAsInheritanceContext( DependencyObject doValue, Dependen
             // on side-effects from setting the "Freezable context".  Freezable's
             // implementation does its own checks of the conditions omitted here.
             // Enhancement suggestion: Freezable should follow the same rules for
-            // InheritanceContext as everyone else 
+            // InheritanceContext as everyone else
 
 
             if (doValue != null &&
@@ -3534,6 +3534,7 @@ internal enum UpdateResult
     }
 
     [FriendAccessAllowed] // Built into Base, also used by Framework.
+    [Flags]
     internal enum RequestFlags
     {
         FullyResolved = 0x00,