树视图,HierarchicalDataTemplate和递归数据(TreeView, Hierar

2019-07-21 02:05发布

对于我的TreeView我有两个不同的类,提供的ItemsSource。

public class TreeViewModel : ViewModelBase
{
    public ObservableCollection<NodeViewModel> Items { get; set; }
}

public class NodeViewModel : ViewModelBase
{
    public string Id { get; set; }
    public string Name { get; set; }
    public ObservableCollection<NodeViewModel> Children { get; set; }
}

现在,我想我的TreeView,以显示TreeViewModel的项目,显示由NodeViewModel提供分层数据。

这是我的XAML

<Window x:Class="TreeViewMasterDetails.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:TreeViewMasterDetails" 
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <TreeView Height="Auto" 
                  HorizontalAlignment="Stretch" 
                  Margin="10" 
                  VerticalAlignment="Stretch" 
                  Width="Auto">
            <TreeView.Resources>
                <HierarchicalDataTemplate DataType="x:Type local:TreeViewModel" ItemsSource="{Binding Items}">
                    <TextBlock Text="{Binding Path=Name}"></TextBlock>
                </HierarchicalDataTemplate>
                <HierarchicalDataTemplate DataType="x:Type local:NodeViewModel" ItemsSource="{Binding Children}">
                    <TextBlock Text="{Binding Name}"></TextBlock>
                </HierarchicalDataTemplate>
            </TreeView.Resources>
        </TreeView>
    </Grid>
</Window>

试图提供Items作为ItemsSource中的TreeView 。 它不分级显示的数据,如果任何显示。

我试着使用ItemTemplate代替的TreeView.Resources了。

有什么不对呢?

也许问题是第一个TextBlock Text Binding ? 我想显示的Name的财产NodeViewModelItems那里。

Answer 1:

正如@ sa_ddam213说,你只需要HierarchicalDataTemplateNodeViewModel ,但你的代码的唯一问题是缺少大括号( {} )的DataType="x:Type local:TreeViewModel"在您的数据模板定义(这应该是DataType="{x:Type local:TreeViewModel}" 添加支架和ItemsSource绑定解决了这个问题:

附加HierarchicalDataTemplateTreeViewModel不使用,但它不会伤害。



Answer 2:

您应该只有申报HierarchicalDataTemplateNodeViewModel ,因为这是在展示的唯一TreeView ,与实际结合ItemSourceTreeView

<TreeView ItemsSource="{Binding Items}">
    <TreeView.Resources>
        <HierarchicalDataTemplate DataType="{x:Type local:NodeViewModel}" ItemsSource="{Binding Children}">
            <TextBlock Text="{Binding Name}"></TextBlock>
        </HierarchicalDataTemplate>
    </TreeView.Resources>
</TreeView>

完整的例子

XAML:

<Window x:Class="WpfApplication13.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:WpfApplication13"
        Title="MainWindow" x:Name="UI" Width="343" Height="744.625" >

    <TreeView DataContext="{Binding ElementName=UI, Path=TreeModel}" ItemsSource="{Binding Items}">
        <TreeView.Resources>
            <HierarchicalDataTemplate DataType="{x:Type local:NodeViewModel}" ItemsSource="{Binding Children}">
                <TextBlock Text="{Binding Name}"></TextBlock>
            </HierarchicalDataTemplate>
        </TreeView.Resources>
    </TreeView>

</Window>

码:

public partial class MainWindow : Window
{

    public MainWindow()
    {
        InitializeComponent();
    }

    public TreeViewModel TreeModel
    {
        get
        {
            return new TreeViewModel
            {
                Items = new ObservableCollection<NodeViewModel>{
                           new NodeViewModel { Name = "Root", Children =  new ObservableCollection<NodeViewModel> {
                              new NodeViewModel { Name = "Level1" ,  Children = new ObservableCollection<NodeViewModel>{ 
                                  new NodeViewModel{ Name = "Level2"}}} } }}
            };
        }
    }
}

public class TreeViewModel
{
    public ObservableCollection<NodeViewModel> Items { get; set; }
}

public class NodeViewModel
{
    public string Id { get; set; }
    public string Name { get; set; }
    public ObservableCollection<NodeViewModel> Children { get; set; }
}

结果:



文章来源: TreeView, HierarchicalDataTemplate and recursive Data