小编典典

WPF TreeView HierarchicalDataTemplate-绑定到具有多个子集合的对象

c#

我试图获取一个TreeView绑定我的收藏集的方法,以便所有组都显示嵌套的组,而每个组都将显示条目。

我该如何使用HierarchicalDataTemplate以便TreeView处理子组和条目集合?

组显示子组和条目:

Example:
Group1
--Entry
--Entry
Group2
--Group4
----Group1
------Entry
------Entry
----Entry
----Entry
--Entry
--Entry
Group3
--Entry
--Entry

对象:


namespace TaskManager.Domain
{
    public class Entry
    {
        public int Key { get; set; }
        public string Name { get; set; }
    }
}

namespace TaskManager.Domain
{
    public class Group
    {
        public int Key { get; set; }
        public string Name { get; set; }

        public IList<Group> SubGroups { get; set; }
        public IList<Entry> Entries { get; set; }
    }
}

测试数据:


namespace DrillDownView
{
    public class TestData
    {

        public IList<Group> Groups = new List<Group>();

        public void Load()
        {
            Group grp1 = new Group() { Key = 1, Name = "Group 1", SubGroups = new List<Group>(), Entries = new List<Entry>() };
            Group grp2 = new Group() { Key = 2, Name = "Group 2", SubGroups = new List<Group>(), Entries = new List<Entry>() };
            Group grp3 = new Group() { Key = 3, Name = "Group 3", SubGroups = new List<Group>(), Entries = new List<Entry>() };
            Group grp4 = new Group() { Key = 4, Name = "Group 4", SubGroups = new List<Group>(), Entries = new List<Entry>() };

            //grp1
            grp1.Entries.Add(new Entry() { Key=1, Name="Entry number 1" });
            grp1.Entries.Add(new Entry() { Key=2, Name="Entry number 2" });
            grp1.Entries.Add(new Entry() { Key=3,Name="Entry number 3" });

            //grp2
            grp2.Entries.Add(new Entry(){ Key=4, Name = "Entry number 4"});
            grp2.Entries.Add(new Entry(){ Key=5, Name = "Entry number 5"});
            grp2.Entries.Add(new Entry(){ Key=6, Name = "Entry number 6"});

            //grp3
            grp3.Entries.Add(new Entry(){ Key=7, Name = "Entry number 7"});
            grp3.Entries.Add(new Entry(){ Key=8, Name = "Entry number 8"});
            grp3.Entries.Add(new Entry(){ Key=9, Name = "Entry number 9"});

            //grp4
            grp4.Entries.Add(new Entry(){ Key=10, Name = "Entry number 10"});
            grp4.Entries.Add(new Entry(){ Key=11, Name = "Entry number 11"});
            grp4.Entries.Add(new Entry(){ Key=12, Name = "Entry number 12"});

            grp4.SubGroups.Add(grp1);
            grp2.SubGroups.Add(grp4);

            Groups.Add(grp1);
            Groups.Add(grp2);
            Groups.Add(grp3);
        }
    }
}

XAML:


<Window x:Class="DrillDownView.Window2"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:TaskManager.Domain;assembly=TaskManager.Domain"
        Title="Window2" Height="300" Width="300">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto" />
        </Grid.ColumnDefinitions>

        <TreeView Name="GroupView" Grid.Row="0" Grid.Column="0" ItemsSource="{Binding}">
            <TreeView.Resources>
                <HierarchicalDataTemplate DataType="{x:Type local:Group}" ItemsSource="{Binding SubGroups}">
                    <TextBlock Text="{Binding Path=Name}" />
                </HierarchicalDataTemplate>
                <HierarchicalDataTemplate DataType="{x:Type local:Entry}" ItemsSource="{Binding Entries}">
                    <TextBlock Text="{Binding Path=Name}" />
                </HierarchicalDataTemplate>
            </TreeView.Resources>
        </TreeView>
    </Grid>
</Window>

XAML.CS:


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

    private void LoadView()
    {
        TestData data = new TestData();
        data.Load();
        GroupView.ItemsSource = data.Groups;
    }
}

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收藏
2020-05-19

共1个答案

小编典典

A HierarchicalDataTemplate是一种表达方式,“这就是您呈现这种类型的对象的方式,这是可以探查以找到该对象下的子节点的属性”

因此,您需要一个返回该节点“子级”的属性。例如(如果您不能同时使“组”和“条目”都源自同一个节点类型)

public class Group{ ....
        public IList<object> Items
        {
            get
            {
                IList<object> childNodes = new List<object>();
                foreach (var group in this.SubGroups)
                    childNodes.Add(group);
                foreach (var entry in this.Entries)
                    childNodes.Add(entry);

                return childNodes;
            }
        }

接下来HierarchicalDataTemplate,由于条目没有子项,因此不需要条目。因此,需要更改XAML以使用新的Items属性和DataTemplatefor条目:

<TreeView Name="GroupView" Grid.Row="0" Grid.Column="0" ItemsSource="{Binding}">
    <TreeView.Resources>
        <HierarchicalDataTemplate DataType="{x:Type local:Group}" ItemsSource="{Binding Items}">
            <TextBlock Text="{Binding Path=Name}" />
        </HierarchicalDataTemplate>
        <DataTemplate DataType="{x:Type local:Entry}" >
            <TextBlock Text="{Binding Path=Name}" />
        </DataTemplate>
    </TreeView.Resources>
</TreeView>

这就是它的样子。 输出屏幕截图

2020-05-19