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 > ;
         }
         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 - ;
                 }
                 if (level >= )
                 {
                     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 = ; i <= ; i += )
                 data.Add(new Data() { Name = i.ToString(), Type = "Odd" });

             for (int i = ; i < ; i += )
                 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="" Width="">
     <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="" ItemsSource="{StaticResource data}">
             <ItemsControl.GroupStyle>
                 <GroupStyle>
                     <GroupStyle.Panel>
                         <ItemsPanelTemplate>
                             <UniformGrid Columns=""/>
                         </ItemsPanelTemplate>
                     </GroupStyle.Panel>
                     <GroupStyle.HeaderTemplate>
                         <DataTemplate>
                             <Expander Header="Name"/>
                         </DataTemplate>
                     </GroupStyle.HeaderTemplate>
                 </GroupStyle>
             </ItemsControl.GroupStyle>
         </ItemsControl>

         <StackPanel Grid.Row="" Margin="">
             <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>

Snoop查看视觉树