[英]Get TreeViewItem for TreeView logical element
My tree view seems like this 我的树状图看起来像这样
<TreeView x:Name="ArticlesTreeView" Grid.Column="0" AllowDrop="True">
<TreeView.Resources>
<HierarchicalDataTemplate DataType="{x:Type structure:NewsPaperDocument}" ItemsSource="{Binding Children}">
<TextBlock Text="{Binding Name}" Tag="{Binding Object}" FontWeight="Bold" />
</HierarchicalDataTemplate>
<HierarchicalDataTemplate DataType="{x:Type structure:NewsPaperPage}" ItemsSource="{Binding Children}">
<TextBlock Text="{Binding Name}" Tag="{Binding Object}" Foreground="#00a300" />
</HierarchicalDataTemplate>
<HierarchicalDataTemplate DataType="{x:Type structure:NewsPaperTitle}" ItemsSource="{Binding Children}">
<TextBlock Text="{Binding Name}" Tag="{Binding Object}" Foreground="#da532c" />
</HierarchicalDataTemplate>
<DataTemplate DataType="{x:Type structure:NewsPaperBlock}">
<TextBlock Text="{Binding Name}" Tag="{Binding Object}" Foreground="#2b5797" />
</DataTemplate>
</TreeView.Resources>
</TreeView>
In ArticlesTreeView.SelectedItem
stores instance of classes NewsPaperDocument, NewsPaperPage, etc
. 在
ArticlesTreeView.SelectedItem
存储类NewsPaperDocument, NewsPaperPage, etc
实例。 How can I get TreeViewItem
associated with SelectedItem
? 如何获得与
SelectedItem
相关联的TreeViewItem
? I try to use VisualTreeHelper.GetParent(elem);
我尝试使用
VisualTreeHelper.GetParent(elem);
, but SelectedItem
doesn't has type DependencyObject
,但是
SelectedItem
没有类型DependencyObject
UPD1 Add simple sample, that demonstrate problem. UPD1添加简单的示例,演示问题。
item
in ArticlesTreeView_SelectedItemChanged
always null
ArticlesTreeView_SelectedItemChanged
item
始终为null
XAML XAML
<Window x:Class="TestTree.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:testTree="clr-namespace:TestTree"
Title="MainWindow" Height="350" Width="525">
<Grid>
<TreeView x:Name="ArticlesTreeView" Grid.Column="0" AllowDrop="True" SelectedItemChanged="ArticlesTreeView_SelectedItemChanged">
<TreeView.Resources>
<HierarchicalDataTemplate DataType="{x:Type testTree:A}" ItemsSource="{Binding Children}">
<TextBlock Text="{Binding Name}" FontWeight="Bold" />
</HierarchicalDataTemplate>
<HierarchicalDataTemplate DataType="{x:Type testTree:B}" ItemsSource="{Binding Children}">
<TextBlock Text="{Binding Name}" Foreground="#00a300" />
</HierarchicalDataTemplate>
<DataTemplate DataType="{x:Type testTree:C}">
<TextBlock Text="{Binding Name}" Foreground="#2b5797" />
</DataTemplate>
</TreeView.Resources>
</TreeView>
</Grid>
CS CS
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
namespace TestTree
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
var a = new A
{
Name = "a",
Children = new List<B>
{
new B
{
Name = "b1",
Children = new List<C>
{
new C{Name = "c1"},
new C{Name = "c2"},
new C{Name = "c3"}
},
},
new B
{
Name = "b2",
Children = new List<C>
{
new C{Name = "c1"},
new C{Name = "c2"},
new C{Name = "c3"}
},
},
new B
{
Name = "b3",
Children = new List<C>
{
new C{Name = "c1"},
new C{Name = "c2"},
new C{Name = "c3"}
},
}
}
};
ArticlesTreeView.ItemsSource = new List<A> { a };
}
private void ArticlesTreeView_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
ItemContainerGenerator gen = ArticlesTreeView.ItemContainerGenerator;
var item = gen.ContainerFromItem(ArticlesTreeView.SelectedItem);
}
}
internal class A
{
public string Name { set; get; }
public List<B> Children { set; get; }
}
internal class B
{
public string Name { set; get; }
public List<C> Children { set; get; }
}
internal class C
{
public string Name { set; get; }
}
}
if I got you correctly you want to retrieve the TreeViewItem
from the SelectedItem
如果我正确地知道了您想从
SelectedItem
检索TreeViewItem
so you can make use of ItemContainerGenerator
这样就可以使用
ItemContainerGenerator
ItemContainerGenerator gen = ArticlesTreeView.ItemContainerGenerator;
TreeViewItem item = gen.ContainerFromItem(ArticlesTreeView.SelectedItem) as TreeViewItem;
Get TreeViewItem from nested items 从嵌套项目中获取TreeViewItem
due to the reason that every TreeViewItem
has it's own ItemContainerGenerator
so in order to find the container from the nested items we need to recurse the depth of the tree 由于每个
TreeViewItem
都有其自己的ItemContainerGenerator
的原因,因此为了从嵌套项目中找到容器,我们需要递归树的深度
private void ArticlesTreeView_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
var item = ContainerFromItem(ArticlesTreeView.ItemContainerGenerator, ArticlesTreeView.SelectedItem);
}
private static TreeViewItem ContainerFromItem(ItemContainerGenerator containerGenerator, object item)
{
TreeViewItem container = (TreeViewItem)containerGenerator.ContainerFromItem(item);
if (container != null)
return container;
foreach (object childItem in containerGenerator.Items)
{
TreeViewItem parent = containerGenerator.ContainerFromItem(childItem) as TreeViewItem;
if (parent == null)
continue;
container = parent.ItemContainerGenerator.ContainerFromItem(item) as TreeViewItem;
if (container != null)
return container;
container = ContainerFromItem(parent.ItemContainerGenerator, item);
if (container != null)
return container;
}
return null;
}
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