<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        Height="300" Width="450"
        xmlns:local="using:AvaloniaUI"
        xmlns:db="using:AvaloniaUI.Demos.Book._19.StoreDatabase"
        x:Class="AvaloniaUI.DataGridGrouping"
        Title="DataGridGrouping">
    <Grid>
        <DataGrid Margin="5" x:DataType="local:DataGridGrouping"
                  AutoGenerateColumns="False"
                  ItemsSource="{Binding ProductsView}">

            <DataGrid.Columns>
                <DataGridTextColumn Header="Product" x:DataType="db:Product"
                                    Width="175"
                                    Binding="{Binding ModelName}" />
                <DataGridTextColumn Header="Price" x:DataType="db:Product"
                                    Binding="{Binding UnitCost, StringFormat='{}{0:C}'}" />
                <DataGridTextColumn Header="Model Number" x:DataType="db:Product"
                                    Binding="{Binding ModelNumber}" />
            </DataGrid.Columns>
        </DataGrid>
    </Grid>
</Window>

using Avalonia;
using Avalonia.Collections;
using Avalonia.Controls;
using Avalonia.Markup.Xaml;
using AvaloniaUI.Demos.Book._19.StoreDatabase;
using System.Collections.ObjectModel;

namespace AvaloniaUI;

public partial class DataGridGrouping : Window
{
    private StoreDb1 db = new StoreDb1();

    public ObservableCollection<Product> Products { get; }

    public DataGridCollectionView ProductsView { get; }
    public DataGridGrouping()
    {
        InitializeComponent();
        Products = db.GetProducts();

        ProductsView = new DataGridCollectionView(Products);

        // 按 CategoryName 分组
        ProductsView.GroupDescriptions.Add(new DataGridPathGroupDescription(nameof(Product.CategoryName)));

        DataContext = this;
    }
}