ItemsControl Grouping分组

ItemsControl属性GroupStyle

Grouping再ItemsControl源代码

public class ItemsControl : Control, IAddChild, IGeneratorHost
{
   public static readonly DependencyProperty GroupStyleSelectorProperty;
   private ObservableCollection<GroupStyle> _groupStyle = new ObservableCollection<GroupStyle>();
   
   public ObservableCollection<GroupStyle> GroupStyle
        {
            get
            {
                return this._groupStyle;
            }
        }
        [Bindable(true), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), CustomCategory("Content")]
        public GroupStyleSelector GroupStyleSelector
        {
            get
            {
                return (GroupStyleSelector)base.GetValue(ItemsControl.GroupStyleSelectorProperty);
            }
            set
            {
                base.SetValue(ItemsControl.GroupStyleSelectorProperty, value);
            }
        }

   static ItemsControl()
        {
   ItemsControl.GroupStyleSelectorProperty = DependencyProperty.Register("GroupStyleSelector", typeof(GroupStyleSelector), typeof(ItemsControl), new FrameworkPropertyMetadata(null, new PropertyChangedCallback(ItemsControl.OnGroupStyleSelectorChanged)));
                }

   private void CreateItemCollectionAndGenerator()
        {
            this._items = new ItemCollection(this);
            this._itemContainerGenerator = new ItemContainerGenerator(this);
            this._itemContainerGenerator.ChangeAlternationCount();
            ((INotifyCollectionChanged)this._items).CollectionChanged += new NotifyCollectionChangedEventHandler(this.OnItemCollectionChanged);
            if (this.IsInitPending)
            {
                this._items.BeginInit();
            }
            else
            {
                if (base.IsInitialized)
                {
                    this._items.BeginInit();
                    this._items.EndInit();
                }
            }
            ((INotifyCollectionChanged)this._groupStyle).CollectionChanged += new NotifyCollectionChangedEventHandler(this.OnGroupStyleChanged);
        }

   public bool ShouldSerializeGroupStyle()
        {
            return this.GroupStyle.Count > 0;
        }
        private void OnGroupStyleChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            if (this._itemContainerGenerator != null)
            {
                this._itemContainerGenerator.Refresh();
            }
        }
        private static void OnGroupStyleSelectorChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            ((ItemsControl)d).OnGroupStyleSelectorChanged((GroupStyleSelector)e.OldValue, (GroupStyleSelector)e.NewValue);
        }
        protected virtual void OnGroupStyleSelectorChanged(GroupStyleSelector oldGroupStyleSelector, GroupStyleSelector newGroupStyleSelector)
        {
            if (this._itemContainerGenerator != null)
            {
                this._itemContainerGenerator.Refresh();
            }
        }
   GroupStyle IGeneratorHost.GetGroupStyle(CollectionViewGroup group, int level)
        {
            GroupStyle groupStyle = null;
            if (this.GroupStyleSelector != null)
            {
                groupStyle = this.GroupStyleSelector(group, level);
            }
            if (groupStyle == null)
            {
                if (level >= this.GroupStyle.Count)
                {
                    level = this.GroupStyle.Count - 1;
                }
                if (level >= 0)
                {
                    groupStyle = this.GroupStyle[level];
                }
            }
            return groupStyle;
        }
}

定义数据模型

    public class Data
    {
        public string Name { get; set; }
        public string Value { get; set; }
        public string Type { get; set; }
    }

在设置GroupStyle
后台代码：

public partial class MainWindow : Window
    {
        public MainWindow()
        {
            ObservableCollection<Data> data = new ObservableCollection<Data>();
            for (int i = 1; i <= 9; i += 2)
                data.Add(new Data() { Name = i.ToString(), Type = "Odd" });

            for (int i = 0; i < 10; i += 2)
                data.Add(new Data() { Name = i.ToString(), Type = "Even" });


            this.Resources.Add("data", data);
            InitializeComponent();

            
            ICollectionView vw = CollectionViewSource.GetDefaultView(data);
            vw.GroupDescriptions.Add(new PropertyGroupDescription("Type"));
            
        }

    }

XAML代码：

<Window x:Class="WpfCustomControl_One.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:WpfCustomControl_One"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
    <DataTemplate DataType="{x:Type local:Data}">
        <StackPanel Orientation="Horizontal">
            <TextBlock Text="{Binding Value}"/>
            <TextBlock Text="{Binding Type}" />
        </StackPanel>
    </DataTemplate>
    </Window.Resources>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <ItemsControl Grid.Row="0" ItemsSource="{StaticResource data}">
            <ItemsControl.GroupStyle>
                <GroupStyle>
                    <GroupStyle.Panel>
                        <ItemsPanelTemplate>
                            <UniformGrid Columns="2"/>
                        </ItemsPanelTemplate>
                    </GroupStyle.Panel>
                    <GroupStyle.HeaderTemplate>
                        <DataTemplate>
                            <Expander Header="Name"/>
                        </DataTemplate>
                    </GroupStyle.HeaderTemplate>
                </GroupStyle>
            </ItemsControl.GroupStyle>
        </ItemsControl>

        <StackPanel Grid.Row="1" Margin="5">
            <ListBox ItemsSource="{StaticResource data}">
                <ListBox.GroupStyle>
                    <GroupStyle>
                        <GroupStyle.ContainerStyle>
                            <Style TargetType="GroupItem">
                                <Setter Property="Template">
                                    <Setter.Value>
                                        <ControlTemplate>
                                            <Expander Header="{Binding Name}">
                                                <ItemsPresenter/>
                                            </Expander>
                                        </ControlTemplate>
                                    </Setter.Value>
                                </Setter>
                            </Style>
                        </GroupStyle.ContainerStyle>
                    </GroupStyle>
                </ListBox.GroupStyle>
            </ListBox>
        </StackPanel>
    </Grid>
</Window>

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