Fix: Fixed issue with tab icon not loading properly (#11328)

Author: marcelwgn

src/Files.App/Assets/FilesOpenDialog/FilesLauncher.exe

@@ -234,7 +234,7 @@
 												Margin="{ThemeResource TabViewItemHeaderIconMargin}">
 												<ContentControl
 													x:Name="IconControl"
-													Content="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TabViewTemplateSettings.IconElement}"
+													Content="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TabViewTemplateSettings.IconElement, Mode=OneWay}"
 													Foreground="{ThemeResource TabViewItemIconForeground}"
 													HighContrastAdjustment="None"
 													IsTabStop="False" />
@@ -609,6 +609,7 @@
 						Header="{x:Bind Header, Mode=OneWay}"
 						IconSource="{x:Bind IconSource, Mode=OneWay}"
 						Style="{StaticResource Local.TabViewItem}"
+						Loaded="TabViewItem_Loaded"
 						ToolTipService.ToolTip="{x:Bind ToolTipText, Mode=OneWay}" />
 				</DataTemplate>
 			</TabView.TabItemTemplate>

src/Files.App/UserControls/MultitaskingControl/HorizontalMultitaskingControl.xaml

@@ -1,3 +1,4 @@
+using CommunityToolkit.WinUI.UI;
 using Files.App.Extensions;
 using Files.App.Helpers;
 using Files.App.ViewModels;
@@ -8,6 +9,7 @@
 using System.Linq;
 using Windows.ApplicationModel.DataTransfer;
 using Windows.Storage;
+using static System.Windows.Forms.VisualStyles.VisualStyleElement.Tab;
 
 // The User Control item template is documented at https://go.microsoft.com/fwlink/?LinkId=234236
 
@@ -235,5 +237,18 @@ public Visibility TabStripVisibility
 			DependencyProperty.Register("TabStripVisibility", typeof(Visibility), typeof(HorizontalMultitaskingControl), new PropertyMetadata(Visibility.Visible));
 
 		public Rectangle DragArea => DragAreaRectangle;
+
+		private void TabViewItem_Loaded(object sender, RoutedEventArgs e)
+		{
+			if (sender is TabViewItem tvi && tvi.FindDescendant("IconControl") is ContentControl control)
+			{
+				control.Content = (tvi.IconSource as ImageIconSource).CreateIconElement();
+				tvi.RegisterPropertyChangedCallback(TabViewItem.IconSourceProperty, (s, args) =>
+				{
+					if (s is TabViewItem tabViewItem && tabViewItem.FindDescendant("IconControl") is ContentControl iconControl)
+						iconControl.Content = (tabViewItem.IconSource as ImageIconSource).CreateIconElement();
+				});
+			}
+		}
 	}
 }