Implement data grouping feature for WinUI TableView

samples/WinUI.TableView.SampleApp/MainPage.xaml

@@ -139,6 +139,11 @@
                         <NavigationViewItem Content="Custom Sorting" />
                     </NavigationViewItem.MenuItems>
                 </NavigationViewItem>
+                <NavigationViewItem Content="Grouping">
+                    <NavigationViewItem.Icon>
+                        <FontIcon Glyph="&#xF168;" />
+                    </NavigationViewItem.Icon>
+                </NavigationViewItem>
                 <NavigationViewItem Content="Filtering">
                     <NavigationViewItem.Icon>
                         <FontIcon Glyph="&#xE71C;" />

samples/WinUI.TableView.SampleApp/MainPage.xaml.cs

@@ -112,6 +112,7 @@ private void OnNavigationSelectionChanged(NavigationView sender, NavigationViewS
                 "Editing" => typeof(EditingPage),
                 "Sorting" => typeof(SortingPage),
                 "Custom Sorting" => typeof(CustomizeSortingPage),
+                "Grouping" => typeof(GroupingPage),
                 "Data Export" => typeof(ExportPage),
                 "Large Dataset" => typeof(LargeDataPage),
                 "Conditional Cell Styling" => typeof(ConditionalStylingPage),

samples/WinUI.TableView.SampleApp/Pages/GroupingPage.xaml

@@ -0,0 +1,76 @@
+<Page x:Class="WinUI.TableView.SampleApp.Pages.GroupingPage"
+      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+      xmlns:local="using:WinUI.TableView.SampleApp"
+      xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+      xmlns:tv="using:WinUI.TableView"
+      xmlns:controls="using:WinUI.TableView.SampleApp.Controls"
+      d:DataContext="{d:DesignInstance Type=local:ExampleViewModel}"
+      mc:Ignorable="d">
+
+    <Grid>
+        <controls:SamplePresenter Header="Row Grouping"
+                                  Description="Group rows by a data field using the GroupByPath property. Users can expand and collapse groups, and control group header visibility and item counts.">
+            <controls:SamplePresenter.Example>
+                <tv:TableView ItemsSource="{Binding Items}"
+                              GroupByPath="{x:Bind GroupByPath, Mode=OneWay}"
+                              ShowGroupHeaders="{Binding IsOn, ElementName=showGroupHeaders, Mode=TwoWay}"
+                              ShowGroupItemCount="{Binding IsOn, ElementName=showItemCount, Mode=TwoWay}"
+                              GroupSortDirection="{x:Bind GroupSortDirection, Mode=OneWay}" />
+            </controls:SamplePresenter.Example>
+            <controls:SamplePresenter.Options>
+                <StackPanel VerticalAlignment="Top"
+                            Spacing="12">
+                    <ComboBox x:Name="groupByComboBox"
+                              Header="Group By"
+                              Width="200"
+                              SelectedIndex="0"
+                              SelectionChanged="OnGroupBySelectionChanged">
+                        <ComboBoxItem Content="Department" Tag="Department" />
+                        <ComboBoxItem Content="Gender" Tag="Gender" />
+                        <ComboBoxItem Content="Designation" Tag="Designation" />
+                        <ComboBoxItem Content="(None)" Tag="" />
+                    </ComboBox>
+                    <ComboBox x:Name="sortDirectionComboBox"
+                              Header="Group Sort Direction"
+                              Width="200"
+                              SelectedIndex="0"
+                              SelectionChanged="OnSortDirectionChanged">
+                        <ComboBoxItem Content="Ascending" />
+                        <ComboBoxItem Content="Descending" />
+                    </ComboBox>
+                    <ToggleSwitch x:Name="showGroupHeaders"
+                                  IsOn="True"
+                                  Header="Show Group Headers"
+                                  OnContent="True"
+                                  OffContent="False" />
+                    <ToggleSwitch x:Name="showItemCount"
+                                  IsOn="True"
+                                  Header="Show Item Count"
+                                  OnContent="True"
+                                  OffContent="False" />
+                </StackPanel>
+            </controls:SamplePresenter.Options>
+            <controls:SamplePresenter.Xaml>
+                <x:String xml:space="preserve">
+&lt;tv:TableView ItemsSource="{Binding Items}"
+    GroupByPath="$(GroupByPath)"
+    ShowGroupHeaders="$(ShowGroupHeaders)"
+    ShowGroupItemCount="$(ShowGroupItemCount)"
+    GroupSortDirection="$(GroupSortDirection)">
+                </x:String>
+            </controls:SamplePresenter.Xaml>
+            <controls:SamplePresenter.Substitutions>
+                <controls:CodeSubstitution Key="GroupByPath"
+                                           Value="{x:Bind GroupByPath, Mode=OneWay}" />
+                <controls:CodeSubstitution Key="ShowGroupHeaders"
+                                           Value="{x:Bind showGroupHeaders.IsOn, Mode=OneWay}" />
+                <controls:CodeSubstitution Key="ShowGroupItemCount"
+                                           Value="{x:Bind showItemCount.IsOn, Mode=OneWay}" />
+                <controls:CodeSubstitution Key="GroupSortDirection"
+                                           Value="{x:Bind GroupSortDirection, Mode=OneWay}" />
+            </controls:SamplePresenter.Substitutions>
+        </controls:SamplePresenter>
+    </Grid>
+</Page>

samples/WinUI.TableView.SampleApp/Pages/GroupingPage.xaml.cs

@@ -0,0 +1,54 @@
+using Microsoft.UI.Xaml.Controls;
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+
+namespace WinUI.TableView.SampleApp.Pages;
+
+public sealed partial class GroupingPage : Page, INotifyPropertyChanged
+{
+    private string? _groupByPath = "Department";
+    private SortDirection _groupSortDirection = SortDirection.Ascending;
+
+    public GroupingPage()
+    {
+        InitializeComponent();
+    }
+
+    public string? GroupByPath
+    {
+        get => _groupByPath;
+        set { _groupByPath = value; OnPropertyChanged(); }
+    }
+
+    public SortDirection GroupSortDirection
+    {
+        get => _groupSortDirection;
+        set { _groupSortDirection = value; OnPropertyChanged(); }
+    }
+
+    private void OnGroupBySelectionChanged(object sender, SelectionChangedEventArgs e)
+    {
+        if (sender is ComboBox comboBox && comboBox.SelectedItem is ComboBoxItem item)
+        {
+            var path = item.Tag?.ToString();
+            GroupByPath = string.IsNullOrEmpty(path) ? null : path;
+        }
+    }
+
+    private void OnSortDirectionChanged(object sender, SelectionChangedEventArgs e)
+    {
+        if (sender is ComboBox comboBox)
+        {
+            GroupSortDirection = comboBox.SelectedIndex == 0
+                ? SortDirection.Ascending
+                : SortDirection.Descending;
+        }
+    }
+
+    public event PropertyChangedEventHandler? PropertyChanged;
+
+    private void OnPropertyChanged([CallerMemberName] string? propertyName = null)
+    {
+        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+    }
+}