【发布时间】：2023-03-22 00:31:01
【问题描述】：
我目前对此很生气：如何通过分层树传播 DataContext？ （假设 MyItem 的子项是已知且固定的，目的是设置框架的源 URI 和 DataContext ） （考虑到其他类别和子项将在以后添加）
首先，这里是一个具体的物品定义：
namespace WpfApplication1
{
using System.Collections.Generic;
public class MyItem
{
public string Name { get; set; }
public List<MyItem> GetItems()
{
return new List<MyItem>() {
new MyItem() { Name = "Item A" },
new MyItem() { Name = "Item B" }
};
}
}
}
其次，具体DataTemplate选择器的定义：
namespace WpfApplication1
{
using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Controls;
using System.Windows;
public class MyTemplateSelector : DataTemplateSelector
{
public static List<DataTemplate> DataTemplates = new List<DataTemplate>();
public override System.Windows.DataTemplate SelectTemplate(object item, System.Windows.DependencyObject container)
{
var datatemplate = DataTemplates.FirstOrDefault(dt => dt.DataType as Type == item.GetType());
return datatemplate ?? base.SelectTemplate(item, container);
}
}
}
第三，这里是主窗口
<Window x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:my="clr-namespace:WpfApplication1"
Title="MainWindow" Height="250" Width="800" >
<Window.Resources>
<ObjectDataProvider x:Key="ItemsProvider" ObjectType="{x:Type my:MyItem}" MethodName="GetItems" />
<my:MyTemplateSelector x:Key="MySelector" />
<CompositeCollection x:Key="fixedsubitems">
<HeaderedItemsControl Header="category #i" >
<HeaderedItemsControl Header="Products j" />
<HeaderedItemsControl Header="Products k" />
</HeaderedItemsControl>
</CompositeCollection>
<HierarchicalDataTemplate x:Key="myItemTemplate" DataType="{x:Type my:MyItem}" ItemsSource="{Binding Source={StaticResource fixedsubitems}}" ItemTemplateSelector="{StaticResource MySelector}">
<!--<HierarchicalDataTemplate.ItemContainerStyle>
<Style TargetType="TreeViewItem" >
<Setter Property="DataContext" Value="{Binding RelativeSource={RelativeSource Self}}" ></Setter>
</Style>
</HierarchicalDataTemplate.ItemContainerStyle>-->
<TextBlock Text="{Binding Path=Name}"/>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate x:Key="HeaderedItemsHierarchicalTemplate" DataType="{x:Type HeaderedItemsControl}" ItemsSource="{Binding Path=Items}" ItemTemplateSelector="{StaticResource MySelector}">
<StackPanel Orientation="Horizontal" ContextMenu="{Binding ContextMenu}" >
<TextBlock Text="{Binding Header}" Margin="3" />
</StackPanel>
</HierarchicalDataTemplate>
<CompositeCollection x:Key="sections" >
<HeaderedItemsControl Header="Section #1" >
<HeaderedItemsControl Header="Entry 1.1" >
</HeaderedItemsControl>
<HeaderedItemsControl Header="My items" ItemsSource="{Binding Source={StaticResource ItemsProvider}}" >
</HeaderedItemsControl>
</HeaderedItemsControl>
<HeaderedItemsControl Header="Section #2" >
<HeaderedItemsControl Header="Entry 2.1" >
</HeaderedItemsControl>
<HeaderedItemsControl Header="Entry 2.2" >
</HeaderedItemsControl>
</HeaderedItemsControl>
</CompositeCollection>
</Window.Resources>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="1*" />
<ColumnDefinition Width="3*" />
</Grid.ColumnDefinitions>
<ScrollViewer VerticalScrollBarVisibility="Auto" DataContext="{Binding Source={StaticResource sections}}">
<ListBox Name="list" ItemsSource="{Binding}" HorizontalContentAlignment="Stretch" SelectedItem="{Binding Path=/}">
<ListBox.ItemTemplate>
<DataTemplate >
<StackPanel >
<Border >
<TextBlock Text="{Binding Header}" TextAlignment="Center" VerticalAlignment="Center" Padding="5" />
</Border>
<Border >
<TreeView Name="tv" ItemsSource="{Binding Items}" ItemTemplate="{StaticResource HeaderedItemsHierarchicalTemplate}" >
<TreeView.Resources>
<Style TargetType="TreeViewItem" >
<Setter Property="IsExpanded" Value="True" />
</Style>
</TreeView.Resources>
</TreeView>
</Border>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</ScrollViewer>
<Frame Name="frame" Source="" Grid.Column="1" />
</Grid>
</Window>
最后，MainWindow 后面的代码：
using System.Collections;
using System.Diagnostics;
using System.Linq;
using System.Windows;
namespace WpfApplication1
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
foreach (var res in this.Resources.Cast<DictionaryEntry>())
{
if (res.Value is DataTemplate)
{
MyTemplateSelector.DataTemplates.Add(res.Value as DataTemplate);
}
}
}
}
}
这 4 个文件显示该窗口
点击类别或产品等子项时如何获取 MyItem 上下文？
我尝试了几种使用 ItemContainerStyle 的方法，DataTemplate 资源中定义的 Style 内的 Setter...从未成功！
【问题讨论】：
-
这个答案是否适合您的需求？ stackoverflow.com/a/3255640/579817
-
谢谢@Gman 不完全是，但这个答案让我上路了！
标签： wpf treeview hierarchicaldatatemplate