树视图多级组样式

Question

我正在使用树视图，我希望有一个多级树视图，可以对树的每个级别（所有子项）进行分组。

它似乎适用于第一级别的项目，但当项目下面有子项时，分组样式似乎并未应用。

My Xaml Group Style，HierarchicalDataTemplate，TreeView

        <DataTemplate x:Key="basicGroupStyle">
            <!--Hide the whole grouping header if the group name is empty string-->
            <DockPanel LastChildFill="True" >
                <Border Background="RoyalBlue" 
                        Margin="0" MinHeight="3" Width="5"
                        VerticalAlignment="Center" DockPanel.Dock="Left"/>

                <TextBlock Text="{Binding Name}" 
                            Foreground="Black" 
                            FontSize="8pt" FontWeight="Bold"
                            VerticalAlignment="Center"
                            Margin="5 0 5 0"
                            DockPanel.Dock="Left"/>
                <Border Background="RoyalBlue" 
                        Margin="0" MinHeight="3"
                        VerticalAlignment="Center"/>
            </DockPanel>
        </DataTemplate>

        <HierarchicalDataTemplate DataType="{x:Type explorer:TreeItem}"
                          ItemsSource="{Binding TreeViewItemsView}">
            <!--Hide the whole grouping header if the group name is empty string-->
            <DockPanel LastChildFill="True" >

                <TextBlock Text="{Binding Name}" 
                            Foreground="Black" 
                            FontSize="8pt" FontWeight="Bold"
                            VerticalAlignment="Center"
                            Margin="5 0 5 0"
                            DockPanel.Dock="Left"/>
            </DockPanel>
        </HierarchicalDataTemplate>

    <TreeView ItemsSource="{Binding TreeViewItemsView}">
        <TreeView.GroupStyle>
            <GroupStyle  HeaderTemplate="{StaticResource basicGroupStyle}" />
        </TreeView.GroupStyle>
    </TreeView>

转换器/组说明

public class AssetTypeExplorerValueConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        var v = value as int?;
        if (v == null)
            return value;

        return Convert(v);
    }

    public static string Convert(int? assetData)
    {
        if (assetData.HasValue)
        {
            if (assetData == 1)
                return "First Group";
            else if (assetData == 2)
                return "Second Group";
            else if (assetData == 3)
                return "Third Group";
            else
                return "Damn";
        }

        return string.Empty;
    }
    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

TreeItem类

    public int level { get; set; }

    public string Name { get; set; }

    private ICollectionView _treeViewItemsView;
    private ObservableCollection<TreeItem> _treeViewItems;

    public ObservableCollection<TreeItem> TreeViewItems
    {
        get { return _treeViewItems ?? (TreeViewItems = new ObservableCollection<TreeItem>()); }
        set { _treeViewItems = value; }
    }

    public ICollectionView TreeViewItemsView
    {
        get
        {
            if (_treeViewItemsView == null)
            {
                _treeViewItemsView = CollectionViewSource.GetDefaultView(TreeViewItems) as ListCollectionView;
            }

            return _treeViewItemsView;
        }
    }

    private void Initalize()
    {
        (this.TreeViewItemsView as ListCollectionView).GroupDescriptions.Clear();
        (this.TreeViewItemsView as ListCollectionView).GroupDescriptions.Add(new PropertyGroupDescription("level", new AssetTypeExplorerValueConverter()));

    }

TreeItems的集合（在构造函数上调用Initalize）

    private ICollectionView _treeViewItemsView;
    private ObservableCollection<TreeItem> _treeViewItems;
    public ICollectionView TreeViewItemsView
    {
        get
        {
            if (_treeViewItemsView == null)
            {
                _treeViewItemsView = CollectionViewSource.GetDefaultView(TreeViewItems) as ListCollectionView;
            }

            return _treeViewItemsView;
        }

    }

    public ObservableCollection<TreeItem> TreeViewItems
    {
        get { return _treeViewItems ?? (TreeViewItems = new ObservableCollection<TreeItem>()); }
        set { _treeViewItems = value; }
    }

    private void SetupItems()
    {
        var first = new TreeItem() { Name = "First Level First Item", level = 1 };
        var secLevel = new TreeItem() { Name = "Second Level First Item", level = 2 };
        first.TreeViewItems.Add(secLevel);


        TreeViewItems.Add(first);
        TreeViewItems.Add(new TreeItem() { Name = "Second Item", level = 1 });
        TreeViewItems.Add(new TreeItem() { Name = "Third Item", level = 1 });

    }

    private void Initalize()
    {
        (this.TreeViewItemsView as ListCollectionView).GroupDescriptions.Clear();
        (this.TreeViewItemsView as ListCollectionView).GroupDescriptions.Add(new PropertyGroupDescription("level", new AssetTypeExplorerValueConverter()));

        SetupItems();
    }

知道为什么会这样吗？ 任何帮助将不胜感激！谢谢！

Answer 1

一个建议;

将HierarchicalDatatemplate分配给TreeView。

<HierarchicalDataTemplate x:Key="TestTemplate"  .... HierarchicalDataTemplate>

<TreeView ItemTemplate="{StaticResource TestTemplate}" ..... TreeView>