WPF / XAML的TreeView绑定后不Hightlight节点 [英] WPF/XAML TreeView doesn't Hightlight Nodes after Binding

问题描述

所以我有TreeView的一个问题。如果我建一个树视图静态，树中的每个节点是在可选择的，当我点击它，它突出自身蓝色，表示该节点已被选中。

So I am having an issue with the TreeView. If I build a tree view statically, every node in the tree is selectable in that when I click on it, it highlights itself blue, indicating that node is selected.

<TreeView 
    Grid.Column="0"
    Grid.Row="2"
    MinHeight="100" 
    MinWidth="100"
    BorderBrush="White"
    DataContext="{Binding Projects, Source={x:Static SizingApp:Manager.Instance}}">
<TreeViewItem Header="Project 1" IsExpanded="True">
    <TreeViewItem Header="Step 1" IsExpanded="True">
        <TreeViewItem Header="Load 1" IsExpanded="True"></TreeViewItem>
        <TreeViewItem Header="Load 2" IsExpanded="True"></TreeViewItem>
    </TreeViewItem>
    <TreeViewItem Header="Step 2" IsExpanded="True">
        <TreeViewItem Header="Load 1" IsExpanded="True"></TreeViewItem>
        <TreeViewItem Header="Load 2" IsExpanded="True"></TreeViewItem>
    </TreeViewItem>
</TreeViewItem>

不过，我绑定到TreeView填充它。此外，我绑定到实现对象的 Emiel容格里斯的BindableObjectBase3类。这是一个美妙的基类的实现，使我的对象是可绑定并实施人工管理的DependencyProperty的关注INotifyPropertyChanged接口。

However, I am Binding to the TreeView to populate it. Furthermore, I am binding to objects that implement Emiel Jongerius's BindableObjectBase3 class. This is a wonderful base class implementation that allows my objects to be Bindable and implement the INotifyPropertyChanged interface with the concern for manual DependencyProperty management.

所以，这是基本的类结构（从我的实际对象简化的），我想在一个TreeView实现。

So this is the basic class structure (simplified from my actual objects) that I am trying to implement in a TreeView.

    public abstract class MyCustomClass : BindableObjectBase3
{
    private string m_strName;

    public virtual string Name
    {
        get
        {
            using (this.GetPropertyTracker(() => this.Name))
            {
                return m_strName;
            }
        }
        set
        {
            this.SetValue(ref this.m_strName, value, () => this.Name);
        }
    }
}

public class Project : MyCustomClass
{
    private List<Step> m_steps;

    public List<Step> Steps
    {
        get
        {
            using (this.GetPropertyTracker(() => this.Steps))
            {
                return m_steps;
            }
        }
        set
        {
            this.SetValue(ref this.m_steps, value, () => this.Steps);
        }
    }
}

public class Step : MyCustomClass
{
    private List<Load> m_loads;

    public List<Load> Loads
    {
        get
        {
            using (this.GetPropertyTracker(() => this.Loads))
            {
                return m_loads;
            }
        }
        set
        {
            this.SetValue(ref this.m_loads, value, () => this.Steps);
        }
    }
}

public class Load : MyCustomClass
{
}

这是基本的XAML我用它来实现的TreeView：

And this is the basic XAML I use to implement the TreeView:

<TreeView 
    Grid.Column="0"
    Grid.Row="2"
    MinHeight="100" 
    MinWidth="100"
    BorderBrush="White"
    DataContext="{Binding Projects, Source={x:Static SizingApp:Manager.Instance}}">
    <TreeView.Resources>
        <HierarchicalDataTemplate x:Key="LoadTemplate">
            <TreeViewItem Header="{Binding Path=Name}">
            </TreeViewItem>
        </HierarchicalDataTemplate>
        <HierarchicalDataTemplate x:Key="StepTemplate">
            <TreeViewItem Header="{Binding Path=Name}" IsExpanded="True"
                    ItemsSource="{Binding Path=Loads}"
                    ItemTemplate="{StaticResource LoadTemplate}">
            </TreeViewItem>
        </HierarchicalDataTemplate>
        <HierarchicalDataTemplate x:Key="ProjectTemplate">
            <TreeViewItem Header="{Binding Path=Name}" IsExpanded="True"
                    ItemsSource="{Binding Path=Steps}"
                    ItemTemplate="{StaticResource StepTemplate}">
            </TreeViewItem>
        </HierarchicalDataTemplate>
    </TreeView.Resources>
    <TreeViewItem 
            Header="{Resx ResxName=PSSPECApplication.Controls.ProjectControlResources, Key=projectTree_Header}"
            ItemsSource="{Binding}"
            IsExpanded="True"
            Focusable="True"
            ItemTemplate="{StaticResource ProjectTemplate}">
    </TreeViewItem>
</TreeView>

现在这一切工作正常，尽可能结合去。我可以绑定到一个ObservableCollection＆LT;项目＆GT;当我添加/删除/处理项目时，TreeView相应地更新。

Now all of this works fine as far as binding goes. I can bind to an ObservableCollection<Project> and as I add/remove/manipulate projects, the TreeView updates accordingly.

然而，在TreeView似乎可选择的唯一节点是所述第一节点（一个是静态的）。所有其他节点通过动态绑定创建并不表示他们在GUI中选择。我希望，他们也会当点击蓝色突出。但相反，他们什么都不做。有没有人有原因的想法？

However, the only node in the TreeView that seems selectable is the first node (the one that is static). All of the other nodes create through dynamic Binding do not indicate that they are selected on the GUI. I would expect that they would also highlight blue when clicked on. But instead they do nothing. Does anyone have an idea of why?

推荐答案

您不应该在明确的界定的ItemTemplate TreeViewItems。你不能选择任何项目的原因是，他们没有父母TreeView控件来控制选择行为。你需要让TreeView中为您生成的TreeViewItem控件和只使用项目模板来定义页眉的用户界面，并为他们的项目的绑定。使用这样的事情，而不是：

You shouldn't be defining TreeViewItems explicitly in your ItemTemplates. The reason you can't select any of the items is that they have no parent TreeView to control selection behavior. You need to let the TreeView generate the TreeViewItem controls for you and only use the item templates to define the UI for the Headers and the bindings for their items. Use something like this instead:

<Window.Resources>
    <HierarchicalDataTemplate x:Key="LoadTemplate">
        <TextBlock Text="{Binding Path=Name}"/>
    </HierarchicalDataTemplate>
    <HierarchicalDataTemplate x:Key="StepTemplate" ItemsSource="{Binding Loads}" ItemTemplate="{StaticResource LoadTemplate}">
        <TextBlock Text="{Binding Path=Name}"/>
    </HierarchicalDataTemplate>
    <HierarchicalDataTemplate x:Key="ProjectTemplate" ItemsSource="{Binding Steps}" ItemTemplate="{StaticResource StepTemplate}">
        <TextBlock Text="{Binding Path=Name}"/>
    </HierarchicalDataTemplate>
</Window.Resources>

<TreeView MinHeight="100" MinWidth="100" BorderBrush="White"
          ItemsSource="{Binding Path=Projects}"
          ItemTemplate="{StaticResource ProjectTemplate}">
    <TreeView.ItemContainerStyle>
        <Style TargetType="{x:Type TreeViewItem}">
            <Setter Property="IsExpanded" Value="True" />
        </Style>
    </TreeView.ItemContainerStyle>
</TreeView>

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