我试图使用数据绑定将层次结构绑定到TreeView,但TreeView中没有显示任何内容。
控件中的XAML代码:
<UserControl x:Class="CQViewer.Views.HierarchyView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:h="clr-namespace:CQViewer.Hierarchy"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<TabControl Margin="5, 0, 5, 5" Grid.Column="0" VerticalAlignment="Stretch" HorizontalAlignment="Stretch">
<TabItem Header="Repository">
<TreeView Margin="5, 5, 5, 5" HorizontalAlignment="Stretch" ItemsSource="{Binding Path=Nodes}">
<TreeView.Resources>
<HierarchicalDataTemplate DataType="{x:Type h:HierarchyNode}"
ItemsSource="{Binding ChildNodes}">
<TextBlock Text="{Binding Name}" />
</HierarchicalDataTemplate>
</TreeView.Resources>
</TreeView>
</TabItem>
<TabItem Header="Libraries">
<ListBox Margin="5, 5, 5, 5" HorizontalAlignment="Stretch" />
</TabItem>
</TabControl>
</Grid>
</UserControl>
我正在使用的类:
using System.Collections.Generic;
namespace CQViewer.Hierarchy
{
class HierarchyNode
{
#region Fields
private IList<HierarchyNode> childNodes_;
#endregion
#region Construction/Deconstruction/Initialisation
/// <summary>
/// Constructor
/// </summary>
public HierarchyNode (string Name)
{
this.Name = Name;
childNodes_ = new List<HierarchyNode> ();
}
#endregion
#region Properties
public string Name { get; set; }
public IList<HierarchyNode> ChildNodes
{
get { return childNodes_; }
set { childNodes_ = value; }
}
#endregion
}
}
我想做的是使用HierarchyNode对象中的ChildNodes填充TreeView,同时显示当前对象名称的TextBlock。根层次结构节点是在ViewModel的构造函数中创建的。此UserControl中的数据绑定有效,因为绑定了List<>到ListBox工作正常。
我正在做的事情出了什么问题,为什么不起作用?
编辑:用于视图的视图模型
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using CQViewer.Hierarchy;
namespace CQViewer.ViewModels
{
class HierarchyViewModel : ViewModelBase
{
#region Fields
#endregion
#region Construction/Deconstruction/Initialisation
/// <summary>
/// Constructor
/// </summary>
public HierarchyViewModel ()
{
Nodes = new HierarchyNode ("Test1");
HierarchyNode Node2 = new HierarchyNode ("TestX");
Node2.ChildNodes.Add (new HierarchyNode ("TestY"));
Nodes.ChildNodes.Add (Node2);
Nodes.ChildNodes.Add (new HierarchyNode ("Test3"));
}
#endregion
#region Properties
public HierarchyNode Nodes { get; set; }
#endregion
#region Public Access Interface
/// <summary>
/// Creates/Recreates the hierarchy
/// </summary>
public void InitializeHierarchy ()
{
// TODO Clear the tree view
}
/// <summary>
/// Gets the folder currently selected in the tree view hierarchy
/// </summary>
public string GetCurrentlySelected ()
{
return "$/";
}
#endregion
#region Private Functions
#endregion
}
}
问题是TreeViewItem
的ItemsSource
属性需要一个集合,其中作为HierarchyViewModel.Nodes
属性的类型为HierarchyNode
。我建议把它改成ObservableCollection<HierarchyNode>
。即:
public ObservableCollection<HierarchyNode> Nodes { get; set; }
使用ItemsSource="{Binding Nodes.ChildNodes}"
的解决方案部分起作用,因为树视图不会显示根节点(在您的情况下,Test1)。
我已经通过将TreeView代码更改为以下代码来实现这一点:
<TreeView Margin="5, 5, 5, 5" HorizontalAlignment="Stretch">
<TreeViewItem Header="{Binding Nodes.Name}" ItemsSource="{Binding Nodes.ChildNodes}">
<TreeViewItem.Resources>
<HierarchicalDataTemplate DataType="{x:Type h:HierarchyNode}"
ItemsSource="{Binding ChildNodes}">
<TextBlock Text="{Binding Name}" />
</HierarchicalDataTemplate>
</TreeViewItem.Resources>
</TreeViewItem>
</TreeView>
但我确信有更好的方法来处理这个问题。