D21_03view_分组 groupby

 

<Window x:Class="demo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"        
        xmlns:db="clr-namespace:StoreDatabase;assembly=StoreDatabase"
        xmlns:local="clr-namespace:demo"
        Title="FilterCollection" Height="390" Width="628"
    >

    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="3*"></ColumnDefinition>
            <ColumnDefinition Width="5*"></ColumnDefinition>
        </Grid.ColumnDefinitions>

        <Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"></RowDefinition>
                <RowDefinition Height="*"></RowDefinition>
                <RowDefinition Height="Auto"></RowDefinition>
            </Grid.RowDefinitions>

            <Button Margin="7,7,7,0" Padding="2" Click="cmdGetProducts_Click">Get Products</Button>
            <ListBox Grid.Row="1" Margin="7,3,7,10" Name="lstProducts" DisplayMemberPath="ModelName">
                <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>


            <Border Grid.Row="2" Margin="7" Padding="7" BorderBrush="SteelBlue" BorderThickness="1" >
                <Grid>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition></ColumnDefinition>
                        <ColumnDefinition></ColumnDefinition>
                    </Grid.ColumnDefinitions>
                    <Grid.RowDefinitions>
                        <RowDefinition></RowDefinition>
                        <RowDefinition></RowDefinition>
                    </Grid.RowDefinitions>
                    <Label>Price > Than</Label>
                    <TextBox Grid.Column="1" Name="txtMinPrice" TextChanged="txtMinPrice_TextChanged">0</TextBox>

                    <Button Grid.Row="1" Margin="2" Padding="2" Click="cmdFilter_Click">Filter</Button>
                    <Button Grid.Row="1" Grid.Column="1" Margin="2" Padding="2" Click="cmdRemoveFilter_Click">Remove Filter</Button>

                </Grid>
            </Border>
        </Grid>

        <GridSplitter Grid.Column="1" HorizontalAlignment="Left" VerticalAlignment="Stretch"
                   Width="5"></GridSplitter>

        <Border Grid.Column="1" Padding="7" Margin="7" Background="LightSteelBlue">
            <Grid DataContext="{Binding ElementName=lstProducts, Path=SelectedItem}" >
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto"></ColumnDefinition>
                    <ColumnDefinition></ColumnDefinition>
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto"></RowDefinition>
                    <RowDefinition Height="Auto"></RowDefinition>
                    <RowDefinition Height="Auto"></RowDefinition>
                    <RowDefinition Height="Auto"></RowDefinition>
                    <RowDefinition Height="*"></RowDefinition>
                </Grid.RowDefinitions>

                <TextBlock Margin="7">Model Number:</TextBlock>
                <TextBox Margin="5" Grid.Column="1" Text="{Binding Path=ModelNumber}"></TextBox>
                <TextBlock Margin="7" Grid.Row="1">Model Name:</TextBlock>
                <TextBox Margin="5" Grid.Row="1" Grid.Column="1" Text="{Binding Path=ModelName}"></TextBox>
                <TextBlock Margin="7" Grid.Row="2">Unit Cost:</TextBlock>
                <TextBox Margin="5" Grid.Row="2" Grid.Column="1" Text="{Binding Path=UnitCost,StringFormat={}{0:C}}"></TextBox>
                <TextBlock Margin="7,7,7,0" Grid.Row="3">Description:</TextBlock>
                <TextBox Margin="7" Grid.Row="4" Grid.Column="0" Grid.ColumnSpan="2" 
                 TextWrapping="Wrap" VerticalScrollBarVisibility="Visible" Text="{Binding Path=Description}"></TextBox>


            </Grid>
        </Border>

    </Grid>
</Window>

 

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

namespace demo
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        private ICollection<Product> products;

        public MainWindow()
        {
            InitializeComponent();    
       
        }

        private void cmdGetProducts_Click(object sender, RoutedEventArgs e)
        {
            products = App.StoreDb.GetProducts();
            lstProducts.ItemsSource = products;

            ICollectionView view = CollectionViewSource.GetDefaultView(lstProducts.ItemsSource);
            //先对CategoryName排序，再对ModelName排序
            view.SortDescriptions.Add(new SortDescription("CategoryName",ListSortDirection.Ascending));
            view.SortDescriptions.Add(new SortDescription("ModelName", ListSortDirection.Ascending));
            //对CategoryName分组
            view.GroupDescriptions.Add(new PropertyGroupDescription("CategoryName"));
        }

        private void cmdFilter_Click(object sender, RoutedEventArgs e)
        {
            decimal minimumPrice;
            if (Decimal.TryParse(txtMinPrice.Text, out minimumPrice))
            {
                ListCollectionView view = (ListCollectionView)CollectionViewSource.GetDefaultView(lstProducts.ItemsSource);

                if (view != null)
                {
                    filterer = new ProductByPriceFilterer(minimumPrice);
                    view.Filter = new Predicate<object>(filterer.FilterItem);
                }
            }
        }

        private void cmdRemoveFilter_Click(object sender, RoutedEventArgs e)
        {
            ListCollectionView view = CollectionViewSource.GetDefaultView(lstProducts.ItemsSource) as ListCollectionView;
            if (view != null)
            {
                view.Filter = null;
            }
        }

        private ProductByPriceFilterer filterer;

        private void txtMinPrice_TextChanged(object sender, TextChangedEventArgs e)
        {
            ListCollectionView view = CollectionViewSource.GetDefaultView(lstProducts.ItemsSource) as ListCollectionView;
            if (view != null)
            {
                decimal minimumPrice;
                if (Decimal.TryParse(txtMinPrice.Text, out minimumPrice) && (filterer != null))
                {
                    filterer.MinimumPrice = minimumPrice;
                    view.Refresh();
                }
            }
        }
    }

    public class ProductByPriceFilterer
    {
        public decimal MinimumPrice
        {
            get;
            set;
        }

        public ProductByPriceFilterer(decimal minimumPrice)
        {
            MinimumPrice = minimumPrice;
        }

        public bool FilterItem(Object item)
        {
            Product product = (Product)item;
            if (product != null)
            {
                if (product.UnitCost > MinimumPrice)
                {
                    return true;
                }
            }
            return false;
        }
    }
}