WPF DataBound树视图展开/折叠 [英] WPF DataBound treeview expand / collapse

问题描述

我只是试图通过他们绑定的对象找到一种控制 TreeView 节点的扩展/崩溃的方法。该对象有一个 IsExpanded 属性，我想使用它来显示基于...的 TreeView 节点本身展开或折叠这个财产。

I'm just trying to find a way to control the expand / collapse of the TreeView nodes through the object they're bound to. The object has an IsExpanded property, and I want to use that to show the TreeView node itself expanded or collapsed based on that property.

这是我的代码：

C＃：

public partial class Window2 : Window
{
    public Window2()
    {
        InitializeComponent();

        this.DataContext = new List<Parent>() { Base.GetParent("Parent 1"), Base.GetParent("Parent 2") };
    }
}

public class Base
{
    public string Name { get; set; }
    public bool IsExpanded { get; set; }

    public static Parent GetParent(string name)
    {
        Parent p = new Parent() { Name = name };

        p.Children.Add(new Child() { Name = "Child 1", GrandChildren = new ObservableCollection<GrandChild>() { new GrandChild() { Name = "Grandchild 1" } } });
        p.Children.Add(new Child() { Name = "Child 2", GrandChildren = new ObservableCollection<GrandChild>() { new GrandChild() { Name = "Grandchild 1" } } });
        p.Children.Add(new Child() { Name = "Child 3", GrandChildren = new ObservableCollection<GrandChild>() { new GrandChild() { Name = "Grandchild 1" } } });

        return p;
    }
}

public class Parent : Base
{
    public ObservableCollection<Child> Children { get; set; }

    public Parent()
    {
        this.Children = new ObservableCollection<Child>();
    }
}

public class Child : Base
{
    public ObservableCollection<GrandChild> GrandChildren { get; set; }

    public Child()
    {
        this.GrandChildren = new ObservableCollection<GrandChild>();
    }
}

public class GrandChild : Base
{
}

XAML：

<Window x:Class="HeterogeneousExperimentExplorer.Window2"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:HeterogeneousTree"
    Title="Window2" Height="300" Width="300">
    <Window.Resources>
        <HierarchicalDataTemplate DataType="{x:Type local:Parent}" ItemsSource="{Binding Children}">
            <TextBlock Text="{Binding Name}" />
            <HierarchicalDataTemplate.ItemTemplate>
                <HierarchicalDataTemplate DataType="{x:Type local:Parent}" ItemsSource="{Binding GrandChildren}">
                    <TextBlock Text="{Binding Name}" />
                    <HierarchicalDataTemplate.ItemTemplate>
                        <DataTemplate>
                            <TextBlock Text="{Binding Name}" />
                        </DataTemplate>
                    </HierarchicalDataTemplate.ItemTemplate>
                </HierarchicalDataTemplate>
            </HierarchicalDataTemplate.ItemTemplate>
        </HierarchicalDataTemplate>
    </Window.Resources>
    <Grid>
        <TreeView ItemsSource="{Binding}" />
    </Grid>
</Window>

推荐答案

解决方案。真的很简单：

Came up with solution. Really simple:

    <Style TargetType="{x:Type TreeViewItem}">
        <Setter Property="IsExpanded" Value="{Binding IsNodeExpanded}">
        </Setter>
    </Style>

因此，样式将对象绑定到TreeViewItem，并查看其IsNodeExpanded属性，并分配该值到TreeViewItem.IsExpanded属性。如果你添加了Mode = TwoWay，他们将通知对方（TreeViewItem会在对象扩展时告诉对象）。

So the style gets the object bound to the TreeViewItem and looks at its IsNodeExpanded attribute and it assigns that value to the TreeViewItem.IsExpanded property. If you add Mode=TwoWay, they'll notify each other (TreeViewItem will tell the object when it has been expanded).

谢谢！

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