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问如何在wpf中开发带有复选框的树形视图？
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Stack Overflow用户

提问于 2010-02-12 18:59:34

回答 5查看 29.9K关注 0票数 8

我有一个要求，我需要动态地将节点添加到TreeView中，并使用CheckBoxes添加节点。如果选择了一个CheckBox，则儿童也会被选中。

我主要是想动态地将数据添加到TreeView中。

wpf

checkbox

treeview

回答 5

Stack Overflow用户

发布于 2010-02-13 04:11:55

一旦你知道怎么做，这就非常简单了。

为您的树视图项目数据创建一个视图模型类(这里我称之为CheckableItem )。它需要这三样东西：

它必须实现INotifyPropertyChanged.

It需要类型为ObservableCollection<CheckableItem>.

It的Children属性需要类型为Visibility的IsChecked属性，该属性在其

方法中引发PropertyChanged，还循环访问Children中的项并设置其IsChecked属性。

在这个类中实现其他属性，以将项的数据公开给绑定(我的示例只是假设有一个名为Value的东西)。或者，您可以只实现object类型的Item类，并在模板中使用ContentPresenter，但我会让您自己解决这个问题。

现在为您的类创建一个HierarchicalDataTemplate，如下所示：

<HierarchicalDataTemplate
    DataType="{x:Type local:CheckableItem}" 
    ItemsSource="{Binding Children}">
    <StackPanel Orientation="Horizontal">
        <CheckBox IsChecked="{Binding IsChecked}"/>
        <TextBlock Text="{Binding Value}"/>
    </StackPanel>
</HierarchicalDataTemplate>

对使用它的TreeView执行...and操作(当然，我假设您已经填充了这些对象的集合)：

<TreeView ItemsSource="{Binding MyCollectionOfCheckableItems}"/>

工作原理：TreeView使用HierarchicalDataTemplate在其ItemsSource中呈现每一项。HierarchicalDataTemplate是一个模板，它创建一个HeaderedItemsControl (在本例中是一个TreeViewItem)，使用它的模板呈现标题，然后使用它的ItemsSource作为控件的项的源-因为它们都是CheckableItems，所以被HierarchicalDataTemplate转换为TreeViewItems。在那之后，海龟就一直往下爬。

This很好地概述了TreeView在实践中是如何工作的，尽管与我发现的大多数示例一样，它有太多花哨的东西，以至于很难看出潜在的原则有多简单。如果你理解MVVM，前面的段落就是你需要知道的90%。

票数 15

Stack Overflow用户

发布于 2015-02-20 01:51:27

看看这个：

DataModel.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;

namespace WpfApplication102
{
    public class Family : DependencyObject
    {
        public string Name { get; set; }
        public List<Person> Members { get; set; }
    }

    public class Person : DependencyObject
    {
        public string Name { get; set; }
    }
}

ItemHelper.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;

namespace WpfApplication102
{
    public class ItemHelper : DependencyObject
    {
        public static readonly DependencyProperty IsCheckedProperty = DependencyProperty.RegisterAttached("IsChecked", typeof(bool?), typeof(ItemHelper), new PropertyMetadata(false, new PropertyChangedCallback(OnIsCheckedPropertyChanged)));
        private static void OnIsCheckedPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if (d is Family && ((bool?)e.NewValue).HasValue)
                foreach (Person p in (d as Family).Members)
                    ItemHelper.SetIsChecked(p, (bool?)e.NewValue);

            if (d is Person)
            {
                int checked = ((d as Person).GetValue(ItemHelper.ParentProperty) as Family).Members.Where(x => ItemHelper.GetIsChecked(x) == true).Count();
                int unchecked = ((d as Person).GetValue(ItemHelper.ParentProperty) as Family).Members.Where(x => ItemHelper.GetIsChecked(x) == false).Count();
                if (unchecked > 0 && checked > 0)
                {
                    ItemHelper.SetIsChecked((d as Person).GetValue(ItemHelper.ParentProperty) as DependencyObject, null);
                    return;
                }
                if (checked > 0)
                {
                    ItemHelper.SetIsChecked((d as Person).GetValue(ItemHelper.ParentProperty) as DependencyObject, true);
                    return;
                }
                ItemHelper.SetIsChecked((d as Person).GetValue(ItemHelper.ParentProperty) as DependencyObject, false);
            }
        }
        public static void SetIsChecked(DependencyObject element, bool? IsChecked)
        {
            element.SetValue(ItemHelper.IsCheckedProperty, IsChecked);
        }
        public static bool? GetIsChecked(DependencyObject element)
        {
            return (bool?)element.GetValue(ItemHelper.IsCheckedProperty);
        }

        public static readonly DependencyProperty ParentProperty = DependencyProperty.RegisterAttached("Parent", typeof(object), typeof(ItemHelper));
        public static void SetParent(DependencyObject element, object Parent)
        {
            element.SetValue(ItemHelper.ParentProperty, Parent);
        }
        public static object GetParent(DependencyObject element)
        {
            return (object)element.GetValue(ItemHelper.ParentProperty);
        }
    }
}

MainWindow.xaml

<Window x:Class="WpfApplication102.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:WpfApplication102"
        Title="MainWindow" Height="220" Width="250">

    <StackPanel>

        <TreeView x:Name="treeView" ItemsSource="{Binding RelativeSource={RelativeSource AncestorType=Window}, Path=Families}">
            <TreeView.Resources>
                <HierarchicalDataTemplate DataType="{x:Type local:Family}" ItemsSource="{Binding Members}" >
                    <CheckBox Content="{Binding Name}" IsChecked="{Binding Path=(local:ItemHelper.IsChecked), Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" >
                        <CheckBox.Style>
                            <Style TargetType="{x:Type CheckBox}">
                                <Setter Property="Foreground" Value="Black"/>
                                <Setter Property="Visibility" Value="Visible"/>
                                <Style.Triggers>
                                    <DataTrigger Binding="{Binding Path=(local:ItemHelper.IsChecked)}" Value="False" >
                                        <Setter Property="Foreground" Value="LightGray"/>
                                    </DataTrigger>
                                </Style.Triggers>
                            </Style>
                        </CheckBox.Style>
                    </CheckBox>
                </HierarchicalDataTemplate>
                <DataTemplate DataType="{x:Type local:Person}" >
                    <CheckBox Content="{Binding Name}" IsChecked="{Binding Path=(local:ItemHelper.IsChecked), Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" >
                        <CheckBox.Style>
                            <Style TargetType="{x:Type CheckBox}">
                                <Setter Property="Foreground" Value="Black"/>
                                <Setter Property="Visibility" Value="Visible"/>
                                <Style.Triggers>
                                    <DataTrigger Binding="{Binding Path=(local:ItemHelper.IsChecked)}" Value="False" >
                                        <Setter Property="Foreground" Value="LightGray"/>
                                    </DataTrigger>
                                </Style.Triggers>
                            </Style>
                        </CheckBox.Style>
                    </CheckBox>
                </DataTemplate>
            </TreeView.Resources>
            <TreeView.ItemContainerStyle>
                <Style TargetType="{x:Type TreeViewItem}">
                    <Setter Property="IsExpanded" Value="True"/>
                </Style>
            </TreeView.ItemContainerStyle>
        </TreeView>

        <Button Content="?" Click="Button_PrintCrew_Click" />

        <TextBlock x:Name="textBoxCrew"/>

    </StackPanel>

</Window>

MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication102
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public ObservableCollection<Family> Families { get; set; }

        public MainWindow()
        {
            InitializeComponent();

            this.Families = new ObservableCollection<Family>();
            this.Families.Add(new Family() { Name = "Simpsons", Members = new List<Person>() { new Person() { Name = "Homer" }, new Person() { Name = "Bart" } } });
            this.Families.Add(new Family() { Name = "Griffin", Members = new List<Person>() { new Person() { Name = "Peter" }, new Person() { Name = "Stewie" } } });
            this.Families.Add(new Family() { Name = "Fry", Members = new List<Person>() { new Person() { Name = "Philip J." } } });

            foreach (Family family in this.Families)
                foreach (Person person in family.Members)
                    person.SetValue(ItemHelper.ParentProperty, family);
        }

        private void Button_PrintCrew_Click(object sender, RoutedEventArgs e)
        {
            string crew = "";
            foreach (Family family in this.Families)
                foreach (Person person in family.Members)
                    if (ItemHelper.GetIsChecked(person) == true)
                        crew += person.Name + ", ";
            crew = crew.TrimEnd(new char[] { ',', ' ' });
            this.textBoxCrew.Text = "Your crew: " + crew;
        }
    }
}

票数 14

Stack Overflow用户

发布于 2017-08-19 00:18:23

我在@pr0gg3r的答案上添加了一些，使其成为通用的。我不确定这是否一定是最好的方法，但它更灵活一些。

MainWindow是相同的，但其他类略有不同。

IParent.cs

interface IParent<T>
{
    IEnumerable<T> GetChildren();
}

DataModel.cs

using System;
using System.Collections.Generic;
using System.Windows;

public class Family : DependencyObject, IParent<object>
{
    public string Name { get; set; }
    public List<Person> Members { get; set; }

    IEnumerable<object> IParent<object>.GetChildren()
    {
        return Members;
    }
}

public class Person : DependencyObject
{
    public string Name { get; set; }
}

ItemHelper.cs

using System.Linq;
using System.Windows;

public class ItemHelper : DependencyObject
{
    public static readonly DependencyProperty IsCheckedProperty =
        DependencyProperty.RegisterAttached("IsChecked", typeof(bool?), typeof(ItemHelper),
            new PropertyMetadata(false, new PropertyChangedCallback(OnIsCheckedPropertyChanged)));

    private static void OnIsCheckedPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        IParent<object> sect = d as IParent<object>;
        DependencyObject depObj = d as DependencyObject;

        if (sect != null)
        {
            if (((bool?)e.NewValue).HasValue)
            {
                foreach (DependencyObject p in sect.GetChildren())
                {
                    SetIsChecked(p, (bool?)e.NewValue);
                }
            }
        }

        if (depObj != null)
        {
            var parentObject = depObj.GetValue(ParentProperty) as IParent<object>;
            var parentDO = depObj.GetValue(ParentProperty) as DependencyObject;
            int ch = parentObject?.GetChildren()?.Where(
                x => GetIsChecked(x as DependencyObject) == true).Count() ?? 0;
            int un = parentObject?.GetChildren()?.Where(
                x => GetIsChecked(x as DependencyObject) == false).Count() ?? 0;
            if (un > 0 && ch > 0)
            {
                SetIsChecked(parentDO, null);
                return;
            }
            if (ch > 0)
            {
                SetIsChecked(parentDO, true);
                return;
            }
            SetIsChecked(parentDO, false);
        }
    }
    public static void SetIsChecked(DependencyObject element, bool? IsChecked)
    {
        element?.SetValue(IsCheckedProperty, IsChecked);
    }
    public static bool? GetIsChecked(DependencyObject element)
    {
        return (bool?)element?.GetValue(IsCheckedProperty);
    }

    public static readonly DependencyProperty ParentProperty =
        DependencyProperty.RegisterAttached("Parent", typeof(object), typeof(ItemHelper));

    public static void SetParent(DependencyObject element, object Parent)
    {
        element?.SetValue(ParentProperty, Parent);
    }
    public static object GetParent(DependencyObject element)
    {
        return element?.GetValue(ParentProperty);
    }
}

票数 4

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/2251260

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