Fix issue with collection change inside item invoked crashing Navigat…

…ionView (microsoft/microsoft-ui-xaml#3138)
Kinnara · Aug 19, 2020 · 08209c5 · 08209c5
1 parent 02f76b4
commit 08209c5
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Showing 3 changed files with 81 additions and 4 deletions.
diff --git a/ModernWpf.Controls/NavigationView/NavigationView.cs b/ModernWpf.Controls/NavigationView/NavigationView.cs
@@ -782,7 +782,13 @@ void RaiseItemInvokedForNavigationViewItem(NavigationViewItem nvi)
             {
                 var inspectingDataSource = (InspectingDataSource)itemsSourceView;
                 var itemIndex = parentIR.GetElementIndex(nvi);
-                nextItem = inspectingDataSource.GetAt(itemIndex);
+
+                // Check that index is NOT -1, meaning it is actually realized
+                if (itemIndex != -1)
+                {
+                    // Something went wrong, item might not be realized yet.
+                    nextItem = inspectingDataSource.GetAt(itemIndex);
+                }
             }
 
             // Determine the recommeded transition direction.

diff --git a/test/NavigationView_TestUI/Common/NavigationViewPageDataContext.xaml b/test/NavigationView_TestUI/Common/NavigationViewPageDataContext.xaml
@@ -9,7 +9,7 @@
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     mc:Ignorable="d">
 
-    <Grid>
+    <StackPanel Orientation="Horizontal">        
         <muxcontrols:NavigationView
             x:Name="NavView"
             AutomationProperties.Name="NavView"
@@ -28,6 +28,19 @@
                 </StackPanel>
             </StackPanel>
         </muxcontrols:NavigationView>
-    </Grid>
+
+        <muxcontrols:NavigationView
+                Width="400" PaneDisplayMode="Left"
+                MenuItemsSource="{x:Bind Pages, Mode=OneWay}"
+                ItemInvoked="NavigationView_ItemInvoked">
+            <muxcontrols:NavigationView.MenuItemTemplate>
+                <DataTemplate>
+                    <muxcontrols:NavigationViewItem Content="{Binding Name}" AutomationProperties.Name="{Binding Name}"/>
+                </DataTemplate>
+            </muxcontrols:NavigationView.MenuItemTemplate>
+
+            <TextBlock Text="{Binding SelectedPage.Name}" />
+        </muxcontrols:NavigationView>
+    </StackPanel>
 
 </local:TestPage>
diff --git a/test/NavigationView_TestUI/Common/NavigationViewPageDataContext.xaml.cs b/test/NavigationView_TestUI/Common/NavigationViewPageDataContext.xaml.cs
@@ -13,11 +13,33 @@
 using NavigationView = ModernWpf.Controls.NavigationView;
 using NavigationViewSelectionChangedEventArgs = ModernWpf.Controls.NavigationViewSelectionChangedEventArgs;
 using NavigationViewItem = ModernWpf.Controls.NavigationViewItem;
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+using System.Collections.Generic;
 
 namespace MUXControlsTestApp
 {
-    public sealed partial class NavigationViewPageDataContext : TestPage
+    public sealed partial class NavigationViewPageDataContext : TestPage, INotifyPropertyChanged
     {
+        public event PropertyChangedEventHandler PropertyChanged;
+
+        private void NotifyPropertyChanged([CallerMemberName] string propertyName = null)
+        {
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+        }
+
+        private NavViewPageData[] _pages;
+
+        public NavViewPageData[] Pages
+        {
+            get => _pages;
+            set
+            {
+                _pages = value;
+                NotifyPropertyChanged(nameof(Pages));
+            }
+        }
+
         public NavigationViewPageDataContext()
         {
             this.InitializeComponent();
@@ -32,6 +54,32 @@ public NavigationViewPageDataContext()
             }
 
             NavView.SelectedItem = NavView.MenuItems[0];
+
+            Pages = new[]
+            {
+                new NavViewPageData("FirstInvokeChangeItem"),
+                new NavViewPageData("SecondInvokeChangeItem"),
+                new NavViewPageData("ThirdInvokeChangeItem"),
+                new NavViewPageData("FourthInvokeChangeItem"),
+                new NavViewPageData("FifthInvokeChangeItem"),
+                new NavViewPageData("SixthInvokeChangeItem"),
+                new NavViewPageData("SeventhInvokeChangeItem"),
+            };
+        }
+
+        private void NavigationView_ItemInvoked(NavigationView sender, ModernWpf.Controls.NavigationViewItemInvokedEventArgs args)
+        {
+            if (_pages != null && _pages.Length == 0)
+            {
+                return;
+            }
+
+            var page = Pages[0];
+            var newPages = new List<NavViewPageData>();
+            newPages.Add(new NavViewPageData($"Clicked {page.Name}"));
+            newPages.AddRange(Pages);
+
+            Pages = newPages.ToArray();
         }
 
         private void NavView_SelectionChanged(NavigationView sender, NavigationViewSelectionChangedEventArgs args)
@@ -45,5 +93,15 @@ private void GetNavViewActiveVisualStates_Click(object sender, RoutedEventArgs e
             var visualstates = Utilities.VisualStateHelper.GetCurrentVisualStateName(NavView);
             NavViewActiveVisualStatesResult.Text = string.Join(",", visualstates);
         }
+
+        public class NavViewPageData
+        {
+            public string Name { get; set; }
+
+            public NavViewPageData(string name)
+            {
+                Name = name;
+            }
+        }
     }
 }