我正在后面的代码中手动添加 TreeViewItems,并想使用 DataTemplate 来显示它们,但不知道如何操作。我希望做这样的事情,但项目显示为空标题。我究竟做错了什么?
XAML
<Window x:Class="TreeTest.WindowTree"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="WindowTree" Height="300" Width="300">
<Grid>
<TreeView Name="_treeView">
<TreeView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Name}" />
<TextBlock Text="{Binding Path=Age}" />
</StackPanel>
</DataTemplate>
</TreeView.ItemTemplate>
</TreeView>
</Grid>
</Window>
背后的代码
using System.Windows;
using System.Windows.Controls;
namespace TreeTest
{
public partial class WindowTree : Window
{
public WindowTree()
{
InitializeComponent();
TreeViewItem itemBob = new TreeViewItem();
itemBob.DataContext = new Person() { Name = "Bob", Age = 34 };
TreeViewItem itemSally = new TreeViewItem();
itemSally.DataContext = new Person() { Name = "Sally", Age = 28 }; ;
TreeViewItem itemJoe = new TreeViewItem();
itemJoe.DataContext = new Person() { Name = "Joe", Age = 15 }; ;
itemSally.Items.Add(itemJoe);
_treeView.Items.Add(itemBob);
_treeView.Items.Add(itemSally);
}
}
public class Person
{
public string Name { get; set; }
public int Age { get; set; }
}
}
最佳答案
您的 ItemTemplate 试图在 TextBlocks 中呈现“Name”和“Age”属性,但 TreeViewItem 没有“Age”属性并且您没有设置其“Name”。
因为您使用的是 ItemTemplate,所以无需将 TreeViewItems 添加到树中。相反,直接添加您的 Person 实例:
_treeView.Items.Add(new Person { Name = "Sally", Age = 28});
当然,问题在于您的底层对象(“Person”)没有任何层次结构概念,因此没有简单的方法可以将“Joe”添加到“Sally”。有几个更复杂的选项:
您可以尝试处理 TreeView.ItemContainerGenerator.StatusChanged 事件并等待生成“Sally”项目,然后获取它的句柄并直接添加 Joe:
public Window1()
{
InitializeComponent();
var bob = new Person { Name = "Bob", Age = 34 };
var sally = new Person { Name = "Sally", Age = 28 };
_treeView.Items.Add(bob);
_treeView.Items.Add(sally);
_treeView.ItemContainerGenerator.StatusChanged += (sender, e) =>
{
if (_treeView.ItemContainerGenerator.Status != GeneratorStatus.ContainersGenerated)
return;
var sallyItem = _treeView.ItemContainerGenerator.ContainerFromItem(sally) as TreeViewItem;
sallyItem.Items.Add(new Person { Name = "Joe", Age = 15 });
};
}
或者,更好的解决方案是,您可以将层次结构概念引入到“人”对象中,并使用 HierarchicalDataTemplate 来定义 TreeView 层次结构:
XAML:
<Window x:Class="TreeTest.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="WindowTree" Height="300" Width="300">
<Grid>
<TreeView Name="_treeView">
<TreeView.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding Subordinates}">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Name}" />
<TextBlock Text="{Binding Path=Age}" />
</StackPanel>
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>
</Grid>
</Window>
代码:
using System.Collections.Generic;
using System.Windows;
namespace TreeTest
{
/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
var bob = new Person { Name = "Bob", Age = 34 };
var sally = new Person { Name = "Sally", Age = 28 };
_treeView.Items.Add(bob);
_treeView.Items.Add(sally);
sally.Subordinates.Add(new Person { Name = "Joe", Age = 15 });
}
}
public class Person
{
public Person()
{
Subordinates = new List<Person>();
}
public string Name { get; set; }
public int Age { get; set; }
public List<Person> Subordinates { get; private set; }
}
}
这是一种更“面向数据”的方式来显示您的层次结构和更好的方法恕我直言。
关于wpf - 在代码中添加项目时将 ItemTemplate 用于 TreeView,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/1175039/