Fix the AOT issue with custom binding of IsSelected property through CVS in Mail List.

Wino.Mail.WinUI/Controls/ListView/WinoListView.cs

@@ -69,7 +69,7 @@ public partial class WinoListView : Microsoft.UI.Xaml.Controls.ListView
             && container.Item != mailItemViewModel)
         {
             container.Item = mailItemViewModel;
-            container.IsSelected = mailItemViewModel.IsSelected;
+            container.IsCustomSelected = mailItemViewModel.IsSelected;
         }
         else if (item is ThreadMailItemViewModel threadMailItemViewModel
             && element is WinoThreadMailItemViewModelListViewItem threadContainer
@@ -88,7 +88,7 @@ public partial class WinoListView : Microsoft.UI.Xaml.Controls.ListView
         if (item is MailItemViewModel mailItemViewModel && element is WinoMailItemViewModelListViewItem container)
         {
             container.Item = null;
-            container.IsSelected = false;
+            container.IsCustomSelected = false;
         }
         else if (item is ThreadMailItemViewModel threadMailItemViewModel && element is WinoThreadMailItemViewModelListViewItem threadContainer)
         {

Wino.Mail.WinUI/Controls/ListView/WinoListViewStyles.xaml

@@ -49,7 +49,7 @@
                                         HorizontalAlignment="Center"
                                         Background="{ThemeResource ListViewItemSelectionIndicatorBrush}"
                                         CornerRadius="4"
-                                        Visibility="{Binding RelativeSource={RelativeSource Mode=TemplatedParent}, Path=Item.IsSelected, Mode=OneWay}" />
+                                        Visibility="{Binding RelativeSource={RelativeSource Mode=TemplatedParent}, Path=IsCustomSelected, Mode=OneWay}" />
 
                                     <!--  Expandable Content  -->
                                     <ContentPresenter
@@ -138,7 +138,7 @@
                                         x:Name="SelectionBackground"
                                         Grid.ColumnSpan="2"
                                         Background="{ThemeResource ListViewItemBackgroundSelected}"
-                                        Visibility="{Binding RelativeSource={RelativeSource Mode=TemplatedParent}, Path=Item.IsSelected, Mode=OneWay}" />
+                                        Visibility="{Binding RelativeSource={RelativeSource Mode=TemplatedParent}, Path=IsCustomSelected, Mode=OneWay}" />
                                     <Border
                                         x:Name="SelectionIndicator"
                                         Width="4"
@@ -146,7 +146,7 @@
                                         HorizontalAlignment="Center"
                                         Background="{ThemeResource ListViewItemSelectionIndicatorBrush}"
                                         CornerRadius="4"
-                                        Visibility="{Binding RelativeSource={RelativeSource Mode=TemplatedParent}, Path=Item.IsSelected, Mode=OneWay}" />
+                                        Visibility="{Binding RelativeSource={RelativeSource Mode=TemplatedParent}, Path=IsCustomSelected, Mode=OneWay}" />
 
                                     <ContentPresenter
                                         x:Name="MailContent"

Wino.Mail.WinUI/Controls/ListView/WinoMailItemViewModelListViewItem.cs

@@ -1,16 +1,45 @@
+using System.ComponentModel;
+using System.Diagnostics;
 using CommunityToolkit.WinUI;
+using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
 using Wino.Mail.ViewModels.Data;
+using WinRT;
 
 namespace Wino.Mail.WinUI.Controls.ListView;
 
+[GeneratedBindableCustomProperty]
 public partial class WinoMailItemViewModelListViewItem : ListViewItem
 {
     [GeneratedDependencyProperty]
     public partial MailItemViewModel? Item { get; set; }
 
+    [GeneratedDependencyProperty]
+    public partial bool IsCustomSelected { get; set; }
+
     public WinoMailItemViewModelListViewItem()
     {
         DefaultStyleKey = typeof(WinoMailItemViewModelListViewItem);
     }
+
+    partial void OnItemPropertyChanged(DependencyPropertyChangedEventArgs e)
+    {
+        Debug.WriteLine("WinoMailItemViewModelListViewItem item changed");
+
+        if (e.OldValue is MailItemViewModel oldMailItemViewModel) UnregisterPropertyChanged(oldMailItemViewModel);
+        if (e.NewValue is MailItemViewModel newMailItemViewModel) RegisterPropertyChanged(newMailItemViewModel);
+    }
+
+    private void RegisterPropertyChanged(MailItemViewModel model) => model.PropertyChanged += ModelPropertyChanged;
+    private void UnregisterPropertyChanged(MailItemViewModel model) => model.PropertyChanged -= ModelPropertyChanged;
+
+    private void ModelPropertyChanged(object? sender, PropertyChangedEventArgs e)
+    {
+        if (sender is not MailItemViewModel mailItemViewModel) return;
+
+        if (e.PropertyName == nameof(MailItemViewModel.IsSelected))
+        {
+            IsCustomSelected = mailItemViewModel.IsSelected;
+        }
+    }
 }

Wino.Mail.WinUI/Controls/ListView/WinoThreadMailItemViewModelListViewItem.cs

@@ -1,12 +1,17 @@
+using System.ComponentModel;
+using System.Diagnostics;
 using System.Linq;
 using CommunityToolkit.WinUI;
+using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
 using Wino.Controls;
 using Wino.Helpers;
 using Wino.Mail.ViewModels.Data;
+using WinRT;
 
 namespace Wino.Mail.WinUI.Controls.ListView;
 
+[GeneratedBindableCustomProperty]
 public partial class WinoThreadMailItemViewModelListViewItem : ListViewItem
 {
     [GeneratedDependencyProperty]
@@ -15,6 +20,8 @@ public partial class WinoThreadMailItemViewModelListViewItem : ListViewItem
     [GeneratedDependencyProperty]
     public partial ThreadMailItemViewModel? Item { get; set; }
 
+    [GeneratedDependencyProperty]
+    public partial bool IsCustomSelected { get; set; }
 
     public WinoThreadMailItemViewModelListViewItem()
     {
@@ -31,4 +38,25 @@ public partial class WinoThreadMailItemViewModelListViewItem : ListViewItem
     }
 
     public WinoExpander? GetExpander() => WinoVisualTreeHelper.FindDescendants<WinoExpander>(this).FirstOrDefault();
+
+    partial void OnItemPropertyChanged(DependencyPropertyChangedEventArgs e)
+    {
+        Debug.WriteLine("WinoMailItemViewModelListViewItem item changed");
+
+        if (e.OldValue is ThreadMailItemViewModel oldMailItemViewModel) UnregisterPropertyChanged(oldMailItemViewModel);
+        if (e.NewValue is ThreadMailItemViewModel newMailItemViewModel) RegisterPropertyChanged(newMailItemViewModel);
+    }
+
+    private void RegisterPropertyChanged(ThreadMailItemViewModel model) => model.PropertyChanged += ModelPropertyChanged;
+    private void UnregisterPropertyChanged(ThreadMailItemViewModel model) => model.PropertyChanged -= ModelPropertyChanged;
+
+    private void ModelPropertyChanged(object? sender, PropertyChangedEventArgs e)
+    {
+        if (sender is not ThreadMailItemViewModel mailItemViewModel) return;
+
+        if (e.PropertyName == nameof(ThreadMailItemViewModel.IsSelected))
+        {
+            IsCustomSelected = mailItemViewModel.IsSelected;
+        }
+    }
 }

Wino.Mail.WinUI/Views/Mail/MailListPage.xaml.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using CommunityToolkit.Mvvm.Collections;
 using CommunityToolkit.Mvvm.Messaging;
 using CommunityToolkit.WinUI;
 using Microsoft.Extensions.DependencyInjection;
@@ -29,6 +30,13 @@ using Wino.Mail.WinUI.Extensions;
 using Wino.MenuFlyouts.Context;
 using Wino.Messaging.Client.Mails;
 using Wino.Views.Abstract;
+using WinRT;
+
+// object, IMailListItem
+// Register generic types from CommunityToolkit.Mvvm for AOT compatibility when passed across WinRT boundary
+[assembly: GeneratedWinRTExposedExternalType(typeof(ObservableGroup<object, IMailListItem>))]
+[assembly: GeneratedWinRTExposedExternalType(typeof(ReadOnlyObservableGroup<object, IMailListItem>))]
+[assembly: GeneratedWinRTExposedExternalType(typeof(ReadOnlyObservableGroupedCollection<object, IMailListItem>))]
 
 namespace Wino.Views.Mail;