c# - Adding TreeView in WPF with context menu in subitems

Question

In my WPF application, I want to add a TreeView control. The tree view control needs to be populated with items from database. So I bind the ItemsSource property to string collection.

Every item in the tree control can have from 0 to 32 child items. Again these items need to be binded. Each of these sub items should have a context menu with two options "Rename" and "Delete". How can I do this in WPF?

Answer 1

有几种方法可以做到这一点。IsLeaf这是使用绑定到底层视图模型上的属性的触发器来应用上下文菜单的一种方法。

MainWindow.xaml：

<Window x:Class="WpfScratch.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

    <Window.Resources>

        <!-- the context menu for all tree view items -->
        <ContextMenu x:Key="TreeViewItemContextMenu">
            <MenuItem Header="Rename" />
            <MenuItem Header="Delete" />
        </ContextMenu>

        <!-- the data template for all tree view items -->
        <HierarchicalDataTemplate x:Key="TreeViewItemTemplate" ItemsSource="{Binding Nodes}">
            <TextBlock x:Name="TextBlock" Text="{Binding Text}" />
            <HierarchicalDataTemplate.Triggers>
                <DataTrigger Binding="{Binding IsLeaf}" Value="True">
                    <Setter TargetName="TextBlock" Property="ContextMenu" Value="{StaticResource TreeViewItemContextMenu}" />
                </DataTrigger>
            </HierarchicalDataTemplate.Triggers>
        </HierarchicalDataTemplate>

    </Window.Resources>

    <!-- the treeview -->
    <TreeView DataContext="{Binding TreeView}"
              ItemsSource="{Binding Nodes}"
              ItemTemplate="{StaticResource TreeViewItemTemplate}">
    </TreeView>

</Window>

MainWindow.xaml.cs：

public partial class MainWindow
{
    public MainWindow()
    {
        InitializeComponent();
        DataContext = new MainWindowModel(
            new MainWindowTreeViewModel(
                new MainWindowTreeViewNodeModel(
                    "1",
                    new MainWindowTreeViewNodeModel("A"),
                    new MainWindowTreeViewNodeModel("B"),
                    new MainWindowTreeViewNodeModel("C")),
                new MainWindowTreeViewNodeModel(
                    "2",
                    new MainWindowTreeViewNodeModel("A"),
                    new MainWindowTreeViewNodeModel("B"),
                    new MainWindowTreeViewNodeModel("C")),
                new MainWindowTreeViewNodeModel(
                    "3",
                    new MainWindowTreeViewNodeModel("A"),
                    new MainWindowTreeViewNodeModel("B"),
                    new MainWindowTreeViewNodeModel("C"))));
    }
}

MainWindowModel.cs：

public class MainWindowModel
{
    public MainWindowModel(MainWindowTreeViewModel treeView)
    {
        TreeView = treeView;
    }

    public MainWindowTreeViewModel TreeView { get; private set; }
}

public class MainWindowTreeViewModel
{
    public MainWindowTreeViewModel(params MainWindowTreeViewNodeModel[] nodes)
    {
        Nodes = nodes.ToList().AsReadOnly();
    }

    public ReadOnlyCollection<MainWindowTreeViewNodeModel> Nodes { get; private set; }
}

public class MainWindowTreeViewNodeModel
{
    public MainWindowTreeViewNodeModel(string text, params MainWindowTreeViewNodeModel[] nodes)
    {
        Text = text;
        Nodes = nodes.ToList().AsReadOnly();
    }

    public string Text { get; private set; }
    public ReadOnlyCollection<MainWindowTreeViewNodeModel> Nodes { get; private set; }
    public bool IsLeaf { get { return Nodes.Count == 0; } }
}