Question

我想将两个或更多类数据绑定为 TreeViewItem 。对于直接示例：文件和文件夹包含在另一个文件夹中，但您最初不知道结构。我想用WPF treeview实现它。但是treeview只能用 HierarchicalDataTemplate （例如我的代码）绑定一种类型的节点。

<DockPanel SizeChanged="FrameworkElement_OnSizeChanged">
    <DockPanel.Resources>
        <HierarchicalDataTemplate x:Key="NodeDataTemplate" 
                                  DataType="{x:Type sideList:SideListNode}" 
                                  ItemsSource="{Binding Path=Children}">

            <StackPanel Orientation="Horizontal">
                <TextBlock VerticalAlignment="Center" x:Name="DisplayName"  Text="{Binding DisplayName}" ></TextBlock>
            </StackPanel>
            <HierarchicalDataTemplate.Triggers>
                <DataTrigger Binding="{Binding Path=}" Value="0">
                    <Setter TargetName="DisplayName" Property="Background" Value="Red">
                    </Setter>
                </DataTrigger>
            </HierarchicalDataTemplate.Triggers>
        </HierarchicalDataTemplate>
    </DockPanel.Resources>

    <TreeView  
        x:Name="SideList" DockPanel.Dock="Left"  MinWidth="200" MaxWidth="250"  Background="Aqua"
              ItemTemplate="{StaticResource NodeDataTemplate}">

    </TreeView>

但当然文件夹和文件之间有一些不同。一些distingct属性为彼此。现在我们需要为创建节点绑定两种类型。一个用于文件，一个用于文件夹。我们怎么做到这一点？

Answer 1

所有可能的类都可以来自诸如

之类的接口

public Interface IGeneralInfo
{
    string info1{get;}
    string info2{get;}
    string info3{get;}
}

然后绑定到接口类型

修改

这里是我可以做的更详细的实际数据
MainWindow.XAML中的

<Window x:Class="DUALBIND.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="MainWindow" Height="350" Width="525"> <Grid> <StackPanel> <Button x:Name="button1" Click="button1_Click" Content="ADD (this is set up for you to test)" FontFamily="Courier New" FontSize="16"/> <ListBox ItemsSource="{Binding}" x:Name="infolist"> <ListBox.ItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal"> <TextBlock Text="{Binding Info1}"/> <TextBlock Text=" :: "/> <TextBlock Text="{Binding Info2}"/> </StackPanel> </DataTemplate> </ListBox.ItemTemplate> </ListBox> </StackPanel> </Grid> </Window>
MainWindows.XAML.cs中的
（没有花时间从项目中删除使用）

using System; using System.Collections.Generic; using System.Collections.ObjectModel;//<-------- notice this 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 DUALBIND { /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window { static Random r = new Random();//best use of random ObservableCollection<IGeneralInfo> generalinfo = new ObservableCollection<IGeneralInfo>(); public MainWindow() { InitializeComponent(); infolist.DataContext = generalinfo; generalinfo.Add(new OBJA()); generalinfo.Add(new OBJA()); generalinfo.Add(new OBJA()); generalinfo.Add(new OBJB(7)); generalinfo.Add(new OBJB(6)); generalinfo.Add(new OBJB(12345)); } private void button1_Click(object sender, RoutedEventArgs e) { /*this was set up for you to play with*/ MessageBox.Show("You get to mess with this"); generalinfo.Add(new OBJB(MainWindow.r.Next())); } } }

在IGeneralInfo.cs
中
using System; namespace DUALBIND { interface IGeneralInfo { string Info1 {get; } string Info2 { get; } } class OBJA : IGeneralInfo { public string Info1 { get { return "Info1 is used"; } } public string Info2 { get { return "Info2 is used"; } } } class OBJB : IGeneralInfo { int x; public OBJB(int X) { x = X; } public string Info1 { get { return "" + x; } } public string Info2 { get { return ""; /*handle this how you want*/} } } }

我的所有工作代码（除非复制和粘贴失败）

Answer 2

拥有公共基类的替代方法是使用一些ItemTemplateSelector。我写了一个通用的：

using System;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Markup;
using System.Collections;
using System.Windows.Media;

namespace Utils
{
    /// <summary>
    /// DataType cannot be null -> define Null type
    /// </summary>
    public class Null
    {
    }

    /// <summary>
    /// Generic template selector selecting the template according to the type
    /// </summary>
    [ContentProperty("Items")]
    public class GenericDataTemplateSelector : DataTemplateSelector
    {
        /// <summary>
        /// Select a template according to the type of the object.
        /// </summary>
        /// <param name="item">The item for which a template shall be selected.</param>
        /// <param name="container">The container, in which the Template shall be used.</param>
        /// <returns>The appropriate template, if found; else null.</returns>
        public override DataTemplate SelectTemplate(object item, System.Windows.DependencyObject container)
        {
            DataTemplate defaultTemplate = null;
            if (item != null)
            {
                foreach (var dataTemplate in Items.OfType<DataTemplate>())
                {
                    if ((Type)dataTemplate.DataType == null || (Type)dataTemplate.DataType == typeof(Null))
                    {
                        defaultTemplate = dataTemplate;
                    }
                    else if (((Type)dataTemplate.DataType).IsInstanceOfType(item))
                    {
                        return dataTemplate;
                    }
                }
            }
            return defaultTemplate;
        }

        /// <summary>
        /// The list of templates.
        /// </summary>
        public IList Items
        {
            get
            {
                if (_items == null)
                {
                    _items = new ArrayList();
                }
                return _items;
            }
            set
            {
                Items.Clear();
                foreach (var item in value)
                {
                    if (item is DataTemplate)
                    {
                        _items.Add(item);
                    }
                }
            }
        }
        IList _items;
    }
}

用法：

    <utils:GenericDataTemplateSelector x:Key="TreeViewTemplateSelector">
        <HierarchicalDataTemplate DataType="{x:Type Type1}">
             ...
        </HierarchicalDataTemplate>

        <HierarchicalDataTemplate DataType="{x:Type Type2}">
             ...
        </HierarchicalDataTemplate>

        <DataTemplate DataType="{x:Type utils:Null}">
             ...
        </DataTemplate>

    </utils:GenericDataTemplateSelector>

WPF Treeview绑定两种或多种类型的数据

2 个答案: