D21_04view_使用范围分组(使用值转换器)

<Window x:Class="demo.GroupInRanges"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="GroupInRanges" Height="300" Width="300"
        xmlns:local="clr-namespace:demo"
        xmlns:component="clr-namespace:System.ComponentModel;assembly=WindowsBase">
    <Window.Resources>
        <!--分组转换器-->
        <local:PriceRangeProductGrouper x:Key="Price50Grouper" GroupInterval="100"></local:PriceRangeProductGrouper>
        <!--CollectionViewSource按价格分组：GroupInterval指定分组间隔-->
        <CollectionViewSource x:Key="GroupByRangeView">
            <CollectionViewSource.SortDescriptions>
                <component:SortDescription PropertyName="UnitCost" Direction="Ascending"></component:SortDescription>
            </CollectionViewSource.SortDescriptions>
            <CollectionViewSource.GroupDescriptions>
                <PropertyGroupDescription PropertyName="UnitCost" Converter="{StaticResource Price50Grouper}"></PropertyGroupDescription>
            </CollectionViewSource.GroupDescriptions>
        </CollectionViewSource>
    </Window.Resources>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"></RowDefinition>
            <RowDefinition></RowDefinition>
        </Grid.RowDefinitions>
        <Button Margin="7,7,7,0" Padding="2" Click="cmdGetProducts_Click">Get Products</Button>
        <!--Binding Source指定CollectionViewSource-->
        <ListBox Grid.Row="1" Margin="7,3,7,10" Name="lstProducts" ItemsSource="{Binding Source={StaticResource GroupByRangeView}}">
            <!--项模板-->
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock>
                        <TextBlock Text="{Binding ModelName}"></TextBlock>
                        (<TextBlock Text="{Binding UnitCost,StringFormat={}{0:C}}"></TextBlock>)
                    </TextBlock>
                </DataTemplate>
            </ListBox.ItemTemplate>
            <!--分组样式-->
            <ListBox.GroupStyle>
                <GroupStyle>
                    <GroupStyle.HeaderTemplate>
                        <DataTemplate>
                            <TextBlock Text="{Binding Path=Name}" FontWeight="Bold" Foreground="White" Background="LightGreen" Margin="0,5,0,0" Padding="3"></TextBlock>
                        </DataTemplate>
                    </GroupStyle.HeaderTemplate>
                </GroupStyle>
            </ListBox.GroupStyle>
        </ListBox>
    </Grid>
</Window>

using System;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
using StoreDatabase;
using System.Collections.Generic;
using System.Windows.Data;

namespace demo
{
    /// <summary>
    /// GroupInRanges.xaml 的交互逻辑
    /// </summary>
    public partial class GroupInRanges : Window
    {
        public GroupInRanges()
        {
            InitializeComponent();
        }

        private ICollection<Product> products;
        private void cmdGetProducts_Click(object sender, RoutedEventArgs e)
        {
            products = App.StoreDb.GetProducts();
            //从xaml中查找CollectionViewSource
            CollectionViewSource viewSource = (CollectionViewSource)this.FindResource("GroupByRangeView");
            //viewSource.Source指向数据集合ICollection<Product> products
            viewSource.Source = products;
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Data;
using System.Globalization;

namespace demo
{
    class PriceRangeProductGrouper : IValueConverter
    {
        public int GroupInterval
        {
            get;
            set;
        }

        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            decimal price = (decimal)value;
            if (price < GroupInterval)
            {
                return String.Format("Less than {0:C}", GroupInterval);
            }
            else
            {
                int interval = (int)price / GroupInterval;
                int lowerLimit = interval * GroupInterval;
                int uperLimit = (interval + 1) * GroupInterval;
                return String.Format("{0:C} to {1:C}",lowerLimit,uperLimit);
            }
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotSupportedException("This converter is for grouping only.");
        }
    }
}