Fix breadcrumb memory leakage issue

demo/Sandbox/ViewModels/MainWindowViewModel.cs

@@ -5,26 +5,5 @@ namespace Sandbox.ViewModels;
 
 public partial class MainWindowViewModel : ViewModelBase
 {
-    public ObservableCollection<DataGridItem> Items { get; set; }
-
-    public MainWindowViewModel()
-    {
-        Items = new ObservableCollection<DataGridItem>()
-        {
-            new DataGridItem() { Name = "John Doe", Age = 42 },
-            new DataGridItem() { Name = "Jane Doe", Age = 39 },
-            new DataGridItem() { Name = "Sammy Doe", Age = 13 },
-            new DataGridItem() { Name = "Barry Doe", Age = 7 },
-            new DataGridItem() { Name = "Molly Doe", Age = 5 },
-        };
-    }
-
 
-}
-
-public class DataGridItem
-{
-    public string? Name { get; set; }
-    public int Age { get; set; }
-    public IPAddress? Address { get; set; }
 }

demo/Sandbox/Views/MainWindow.axaml

@@ -7,19 +7,28 @@
         mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
         x:Class="Sandbox.Views.MainWindow"
         x:DataType="vm:MainWindowViewModel"
-        xmlns:sys="using:System"
         Icon="/Assets/avalonia-logo.ico"
         Title="Sandbox">
-
     <Design.DataContext>
         <!-- This only sets the DataContext for the previewer in an IDE,
              to set the actual DataContext for runtime, set the DataContext property in code (look at App.axaml.cs) -->
         <vm:MainWindowViewModel />
     </Design.DataContext>
-    <u:UrsaView>
-        <Panel>
-            <Button Content="???" Click="Button_OnClick"></Button>
-            <u:OverlayDialogHost HostId="root"></u:OverlayDialogHost>
-        </Panel>
-    </u:UrsaView>
+    <StackPanel>
+        <Button Content="???" Click="Button_OnClick"></Button>
+        <ContentControl Name="content">
+            <ContentControl.DataTemplates>
+                <DataTemplate DataType="x:Int32">
+                    <u:Breadcrumb Separator="·" Classes="Margin">
+                        <u:BreadcrumbItem Content="a" />
+                        <u:BreadcrumbItem Content="b" />
+                        <u:BreadcrumbItem Content="c" />
+                    </u:Breadcrumb>
+                </DataTemplate>
+                <DataTemplate DataType="x:Double">
+                    <TextBlock Text="Hello World"/>
+                </DataTemplate>
+            </ContentControl.DataTemplates>
+        </ContentControl>
+    </StackPanel>
 </Window>

demo/Sandbox/Views/MainWindow.axaml.cs

@@ -13,6 +13,13 @@ public MainWindow()
 
     private async void Button_OnClick(object? sender, RoutedEventArgs e)
     {
-        var res = await OverlayDialog.ShowModal(new TextBlock() { Text = "sdfksjdl" }, "root");
+        if (content.Content is int s)
+        {
+            content.Content = 1.1;
+        }
+        else
+        {
+            content.Content = 1;
+        }
     }
 }

src/Ursa/Controls/Breadcrumb/Breadcrumb.cs

@@ -73,8 +73,21 @@ public IDataTemplate? IconTemplate
     static Breadcrumb()
     {
         ItemsPanelProperty.OverrideDefaultValue<Breadcrumb>(_defaultPanel);
+        SeparatorProperty.Changed.AddClassHandler<Breadcrumb, object?>((b, args) => b.OnSeparatorChanged(args));
     }
-
+
+    private void OnSeparatorChanged(AvaloniaPropertyChangedEventArgs<object?> args)
+    {
+        if (GetSeparatorInstance(Separator) is { } a)
+        {
+            var breadcrumbItems = this.GetVisualDescendants().OfType<BreadcrumbItem>().ToList();
+            foreach (var item in breadcrumbItems)
+            {
+                item.Separator = a;
+            }
+        }
+    }
+
     protected override bool NeedsContainerOverride(object? item, int index, out object? recycleKey)
     {
         return NeedsContainer<BreadcrumbItem>(item, out recycleKey);
@@ -94,11 +107,6 @@ protected override void PrepareContainerForItemOverride(Control container, objec
             {
                 breadcrumbItem.Separator = a;
             }
-            SeparatorProperty.Changed.AddClassHandler<Breadcrumb, object?>((_, args) =>
-            {
-                if (GetSeparatorInstance(args.NewValue.Value) is { } b)
-                    breadcrumbItem.Separator = b;
-            });
         }
 
         if (container == item) return;