feat: remove virtualization subscription feature to avoid potential issue of

src/Ursa/Controls/ComboBox/MultiComboBox.cs

@@ -7,6 +7,7 @@ using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
+using Avalonia.Interactivity;
 using Irihi.Avalonia.Shared.Helpers;
 
 namespace Ursa.Controls;
@@ -59,35 +60,9 @@ public class MultiComboBox: SelectingItemsControl
         return new MultiComboBoxItem();
     }
 
-    private Dictionary<int, IDisposable?> _disposables = new Dictionary<int, IDisposable?>();
-
     protected override void PrepareContainerForItemOverride(Control container, object? item, int index)
     {
         base.PrepareContainerForItemOverride(container, item, index);
-        if(_disposables.TryGetValue(index, out var d))
-        {
-            d?.Dispose();
-            _disposables.Remove(index);
-        }
-        if (container is MultiComboBoxItem comboBoxItem)
-        {
-            comboBoxItem.IsSelected = SelectedItems?.Contains(item) ?? false;
-            var disposable = MultiComboBoxItem.IsSelectedProperty.Changed.Subscribe(a =>
-            {
-                if (a.Sender == comboBoxItem)
-                {
-                    if (comboBoxItem.IsSelected)
-                    {
-                        SelectedItems?.Add(item);
-                    }
-                    else
-                    {
-                        SelectedItems?.Remove(item);
-                    }
-                }
-            });
-            _disposables[index] = disposable;
-        }
     }
 
     internal void ItemFocused(MultiComboBoxItem dropDownItem)
@@ -97,5 +72,4 @@ public class MultiComboBox: SelectingItemsControl
             dropDownItem.BringIntoView();
         }
     }
-    
 }

src/Ursa/Controls/ComboBox/MultiComboBoxItem.cs

@@ -2,12 +2,15 @@
 using Avalonia.Controls;
 using Avalonia.Controls.Mixins;
 using Avalonia.Input;
+using Avalonia.LogicalTree;
 using Irihi.Avalonia.Shared.Helpers;
 
 namespace Ursa.Controls;
 
 public class MultiComboBoxItem: ContentControl
 {
+    private MultiComboBox? _parent;
+    
     public static readonly StyledProperty<bool> IsSelectedProperty = AvaloniaProperty.Register<MultiComboBoxItem, bool>(
         nameof(IsSelected));
 
@@ -22,7 +25,23 @@ public class MultiComboBoxItem: ContentControl
         IsSelectedProperty.AffectsPseudoClass<MultiComboBoxItem>(":selected");
         PressedMixin.Attach<MultiComboBoxItem>();
         FocusableProperty.OverrideDefaultValue<MultiComboBoxItem>(true);
+        IsSelectedProperty.Changed.AddClassHandler<MultiComboBoxItem, bool>((item, args) =>
+            item.OnSelectionChanged(args));
     }
+
+    private void OnSelectionChanged(AvaloniaPropertyChangedEventArgs<bool> args)
+    {
+        var parent = this.FindLogicalAncestorOfType<MultiComboBox>();
+        if (args.NewValue.Value)
+        {
+            parent?.SelectedItems?.Add(this.DataContext);
+        }
+        else
+        {
+            parent?.SelectedItems?.Remove(this.DataContext);
+        }
+    }
+
     public MultiComboBoxItem()
     {
         this.GetObservable(IsFocusedProperty).Subscribe(a=> {
@@ -33,6 +52,14 @@ public class MultiComboBoxItem: ContentControl
         });
     }
 
+    protected override void OnAttachedToLogicalTree(LogicalTreeAttachmentEventArgs e)
+    {
+        base.OnAttachedToLogicalTree(e);
+        _parent = this.FindLogicalAncestorOfType<MultiComboBox>();
+        if(this.IsSelected)
+            _parent?.SelectedItems?.Add(this.DataContext);
+    }
+
     protected override void OnPointerPressed(PointerPressedEventArgs e)
     {
         base.OnPointerPressed(e);