From 5725019bd5fb3f89158e3faa4994b8daeb87c7f1 Mon Sep 17 00:00:00 2001
From: Nzroops <scanfing@foxmail.com>
Date: Tue, 20 Feb 2024 12:39:30 +0800
Subject: [PATCH 1/2] Update NavigationView.Properties.cs

UpdateMenuItemsTemplate And AddItemsToDictionaries when MenuItems changed.
---
 .../NavigationView.Properties.cs              | 52 ++++++++++++++++++-
 1 file changed, 51 insertions(+), 1 deletion(-)

diff --git a/src/Wpf.Ui/Controls/NavigationView/NavigationView.Properties.cs b/src/Wpf.Ui/Controls/NavigationView/NavigationView.Properties.cs
index 592ef644c..5a500562c 100644
--- a/src/Wpf.Ui/Controls/NavigationView/NavigationView.Properties.cs
+++ b/src/Wpf.Ui/Controls/NavigationView/NavigationView.Properties.cs
@@ -7,6 +7,7 @@
 // Copyright(c) Microsoft Corporation.All rights reserved.
 
 using System.Collections;
+using System.Collections.Specialized;
 using System.Windows.Controls;
 using Wpf.Ui.Animations;
 
@@ -82,7 +83,7 @@ public partial class NavigationView
         nameof(FooterMenuItemsProperty),
         typeof(IList),
         typeof(NavigationView),
-        new FrameworkPropertyMetadata(null)
+        new FrameworkPropertyMetadata(null, OnFooterMenuItemsPropertyChanged)
     );
 
     /// <summary>
@@ -513,16 +514,40 @@ private static void OnMenuItemsPropertyChanged(DependencyObject? d, DependencyPr
 
         if (navigationView.MenuItemsItemsControl is null)
         {
+            navigationView.UpdateCollectionChangedEvent(e.OldValue as IList, e.NewValue as IList);
             return;
         }
 
         if (navigationView.MenuItemsItemsControl.ItemsSource.Equals(enumerableNewValue))
         {
+            navigationView.UpdateMenuItemsTemplate(enumerableNewValue);
             return;
         }
 
         navigationView.MenuItemsItemsControl.ItemsSource = null;
         navigationView.MenuItemsItemsControl.ItemsSource = enumerableNewValue;
+        navigationView.UpdateMenuItemsTemplate(enumerableNewValue);
+        navigationView.AddItemsToDictionaries(enumerableNewValue);
+
+        navigationView.UpdateCollectionChangedEvent(e.OldValue as IList, e.NewValue as IList);
+    }
+
+    private void UpdateCollectionChangedEvent(IList? oldMenuItems, IList? newMenuItems)
+    {
+        if(oldMenuItems is INotifyCollectionChanged notifyCollection)
+        {
+            notifyCollection.CollectionChanged -= OnMenuItems_CollectionChanged;
+        }
+        if(newMenuItems is INotifyCollectionChanged newNotifyCollection)
+        {
+            newNotifyCollection.CollectionChanged += OnMenuItems_CollectionChanged;
+        }
+    }
+
+    private void OnMenuItems_CollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
+    {
+        UpdateMenuItemsTemplate(e.NewItems);
+        AddItemsToDictionaries(e.NewItems);
     }
 
     private static void OnMenuItemsSourcePropertyChanged(
@@ -551,6 +576,31 @@ DependencyPropertyChangedEventArgs e
         navigationView.FooterMenuItems = enumerableNewValue;
     }
 
+    private static void OnFooterMenuItemsPropertyChanged(DependencyObject? d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is not NavigationView navigationView || e.NewValue is not IList enumerableNewValue)
+        {
+            return;
+        }
+
+        if (navigationView.FooterMenuItemsItemsControl is null)
+        {
+            navigationView.UpdateCollectionChangedEvent(e.OldValue as IList, e.NewValue as IList);
+            return;
+        }
+
+        if (navigationView.FooterMenuItemsItemsControl.ItemsSource.Equals(enumerableNewValue))
+        {
+            return;
+        }
+
+        navigationView.FooterMenuItemsItemsControl.ItemsSource = null;
+        navigationView.FooterMenuItemsItemsControl.ItemsSource = enumerableNewValue;
+        navigationView.UpdateMenuItemsTemplate(enumerableNewValue);
+        navigationView.AddItemsToDictionaries(enumerableNewValue);
+        navigationView.UpdateCollectionChangedEvent(e.OldValue as IList, e.NewValue as IList);
+    }
+
     private static void OnPaneDisplayModePropertyChanged(
         DependencyObject? d,
         DependencyPropertyChangedEventArgs e

From 43af1005b1c4d960cdf9a2257022c058b9dcccce Mon Sep 17 00:00:00 2001
From: Nzroops <scanfing@foxmail.com>
Date: Tue, 20 Feb 2024 13:58:02 +0800
Subject: [PATCH 2/2] add null check befor
 UpdateMenuItemsTemplate/AddItemsToDictionaries when
 MenuItems_CollectionChanged #964

---
 .../Controls/NavigationView/NavigationView.Properties.cs     | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/Wpf.Ui/Controls/NavigationView/NavigationView.Properties.cs b/src/Wpf.Ui/Controls/NavigationView/NavigationView.Properties.cs
index 5a500562c..4c5ecd779 100644
--- a/src/Wpf.Ui/Controls/NavigationView/NavigationView.Properties.cs
+++ b/src/Wpf.Ui/Controls/NavigationView/NavigationView.Properties.cs
@@ -546,6 +546,11 @@ private void UpdateCollectionChangedEvent(IList? oldMenuItems, IList? newMenuIte
 
     private void OnMenuItems_CollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
     {
+        if (e.NewItems is null)
+        {
+            return;
+        }
+
         UpdateMenuItemsTemplate(e.NewItems);
         AddItemsToDictionaries(e.NewItems);
     }