更新

WPFDark/Internals/PropertyChangeNotifier.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Windows;
+using System.Windows.Data;
+
+namespace WPFDark.Internals
+{
+    // https://stackoverflow.com/questions/23682232/how-can-i-fix-the-dependencypropertydescriptor-addvaluechanged-memory-leak-on-at
+    // https://agsmith.wordpress.com/2008/04/07/propertydescriptor-addvaluechanged-alternative/
+
+    internal sealed class PropertyChangeNotifier : DependencyObject, IDisposable
+    {
+        private readonly WeakReference _propertySource;
+
+        public PropertyChangeNotifier(DependencyObject propertySource, DependencyProperty property)
+            : this(propertySource, new PropertyPath(property))
+        {
+        }
+
+        public PropertyChangeNotifier(DependencyObject propertySource, PropertyPath property)
+        {
+            if (null == propertySource)
+                throw new ArgumentNullException(nameof(propertySource));
+
+            if (null == property)
+                throw new ArgumentNullException(nameof(property));
+
+            _propertySource = new WeakReference(propertySource);
+
+            var binding = new Binding
+            {
+                Path = property,
+                Mode = BindingMode.OneWay,
+                Source = propertySource
+            };
+            BindingOperations.SetBinding(this, ValueProperty, binding);
+        }
+
+        public DependencyObject? PropertySource
+        {
+            get
+            {
+                try
+                {
+                    return _propertySource.IsAlive
+                        ? _propertySource.Target as DependencyObject
+                        : null;
+                }
+                catch
+                {
+                    return null;
+                }
+            }
+        }
+
+        public static readonly DependencyProperty ValueProperty = DependencyProperty.Register("Value",
+            typeof(object), typeof(PropertyChangeNotifier), new FrameworkPropertyMetadata(null, OnPropertyChanged));
+
+        private static void OnPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+        {
+            var notifier = (PropertyChangeNotifier) d;
+            notifier.ValueChanged?.Invoke(notifier, EventArgs.Empty);
+        }
+
+        public object Value
+        {
+            get => GetValue(ValueProperty);
+            set => SetValue(ValueProperty, value);
+        }
+
+        public event EventHandler? ValueChanged;
+
+        public void Dispose()
+        {
+            BindingOperations.ClearBinding(this, ValueProperty);
+        }
+    }
+}