[C#/WINUI3/COMMUNITY TOOLKIT/.NET8] DependencyObjectExtensions 클래스 : FindDescendant/FindDescendants 확장 메소드를 사용해 자식 의존 객체 찾기

■ DependencyObjectExtensions 클래스의 FindDescendant/FindDescendants 확장 메소드를 사용해 자식 의존 객체를 찾는 방법을 보여준다.

※ 비주얼 스튜디오에서 TestProject(Unpackaged) 모드로 빌드한다.
※ TestProject.csproj 프로젝트 파일에서 WindowsPackageType 태그를 None으로 추가했다.

▶ MainPage.xaml


<?xml version="1.0" encoding="utf-8"?>
<Page x:Class="TestProject.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"
    FontFamily="나눔고딕코딩"
    FontSize="16">
    <StackPanel
        HorizontalAlignment="Center"
        VerticalAlignment="Center"
        Spacing="10">
        <ListView Name="listView"
            HorizontalAlignment="Center"
            Width="400"
            Height="400"
            BorderThickness="1"
            BorderBrush="Black"
            ItemsSource="{x:Bind ItemCollection, Mode=OneWay}">
            <ListView.ItemsPanel>
                <ItemsPanelTemplate>
                    <StackPanel
                        Orientation="Vertical" />
                </ItemsPanelTemplate>
            </ListView.ItemsPanel>
        </ListView>
        <TextBlock Name="textBlock"
            HorizontalAlignment="Center" />
    </StackPanel>
</Page>

<?xml version="1.0" encoding="utf-8"?>

<Page x:Class="TestProject.MainPage"

xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"

FontFamily="나눔고딕코딩"

FontSize="16">

<StackPanel

HorizontalAlignment="Center"

VerticalAlignment="Center"

Spacing="10">

<ListView Name="listView"

HorizontalAlignment="Center"

Width="400"

Height="400"

BorderThickness="1"

BorderBrush="Black"

ItemsSource="{x:Bind ItemCollection, Mode=OneWay}">

<ListView.ItemsPanel>

<StackPanel

Orientation="Vertical" />

</ItemsPanelTemplate>

</ListView.ItemsPanel>

</ListView>

<TextBlock Name="textBlock"

HorizontalAlignment="Center" />

</StackPanel>

</Page>

▶ MainPage.xaml.cs


using System;
using System.Linq;
using System.Collections.Generic;
using System.Collections.ObjectModel;

using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;

using CommunityToolkit.WinUI;

namespace TestProject;

/// <summary>
/// 메인 페이지
/// </summary>
public sealed partial class MainPage : Page
{
    //////////////////////////////////////////////////////////////////////////////////////////////////// Property
    ////////////////////////////////////////////////////////////////////////////////////////// Public

    #region 항목 컬렉션 - ItemCollection

    /// <summary>
    /// 항목 컬렉션
    /// </summary>
    public ObservableCollection<string> ItemCollection { get; set; } = [];

    #endregion

    //////////////////////////////////////////////////////////////////////////////////////////////////// Constructor
    ////////////////////////////////////////////////////////////////////////////////////////// Public

    #region 생성자 - MainPage()

    /// <summary>
    /// 생성자
    /// </summary>
    public MainPage()
    {
        InitializeComponent();

        ItemCollection = GetItemCollection(200);

        Loaded += Page_Loaded;
    }

    #endregion

    //////////////////////////////////////////////////////////////////////////////////////////////////// Method
    ////////////////////////////////////////////////////////////////////////////////////////// Private
    //////////////////////////////////////////////////////////////////////////////// Event

    #region 페이지 로드시 처리하기 - Page_Loaded(sender, e)

    /// <summary>
    /// 페이지 로드시 처리하기
    /// </summary>
    /// <param name="sender">이벤트 발생자</param>
    /// <param name="e">이벤트 인자</param>
    private void Page_Loaded(object sender, RoutedEventArgs e)
    {
        StackPanel stackPanel = this.FindDescendant<StackPanel>();

        ListView listView = stackPanel.FindDescendant("listView") as ListView;

        IEnumerable<ListViewItem> listViewItemEnumerable = listView.FindDescendants().OfType<ListViewItem>();

        this.textBlock.Text = listViewItemEnumerable.Count().ToString();
    }

    #endregion

    //////////////////////////////////////////////////////////////////////////////// Function

    #region 항목 컬렉션 구하기 - GetItemCollection(itemCount)

    /// <summary>
    /// 항목 컬렉션 구하기
    /// </summary>
    /// <param name="itemCount">항목 수</param>
    /// <returns>항목 컬렉션</returns>
    private ObservableCollection<string> GetItemCollection(int itemCount)
    {
        ObservableCollection<string> collection = [];

        for(int i = 0; i < itemCount; i++)
        {
            string item = (i % 2) == 0 ? $"{i} - Even" : $"{i} - Odd";

            collection.Add(item);
        }

        return collection;
    }

    #endregion
}

using System;

using System.Linq;

using System.Collections.Generic;

using System.Collections.ObjectModel;

using Microsoft.UI.Xaml;

using Microsoft.UI.Xaml.Controls;

using CommunityToolkit.WinUI;

namespace TestProject;

/// <summary>

/// 메인 페이지

/// </summary>

public sealed partial class MainPage : Page

{

//////////////////////////////////////////////////////////////////////////////////////////////////// Property

////////////////////////////////////////////////////////////////////////////////////////// Public

#region 항목 컬렉션 - ItemCollection

/// <summary>

/// 항목 컬렉션

/// </summary>

public ObservableCollection<string> ItemCollection { get; set; } = [];

#endregion

//////////////////////////////////////////////////////////////////////////////////////////////////// Constructor

////////////////////////////////////////////////////////////////////////////////////////// Public

#region 생성자 - MainPage()

/// <summary>

/// 생성자

/// </summary>

public MainPage()

{

InitializeComponent();

ItemCollection = GetItemCollection(200);

Loaded += Page_Loaded;

}

#endregion

//////////////////////////////////////////////////////////////////////////////////////////////////// Method

////////////////////////////////////////////////////////////////////////////////////////// Private

//////////////////////////////////////////////////////////////////////////////// Event

#region 페이지 로드시 처리하기 - Page_Loaded(sender, e)

/// <summary>

/// 페이지 로드시 처리하기

/// </summary>

/// <param name="sender">이벤트 발생자</param>

/// <param name="e">이벤트 인자</param>

private void Page_Loaded(object sender, RoutedEventArgs e)

{

StackPanel stackPanel = this.FindDescendant<StackPanel>();

ListView listView = stackPanel.FindDescendant("listView") as ListView;

IEnumerable<ListViewItem> listViewItemEnumerable = listView.FindDescendants().OfType<ListViewItem>();

this.textBlock.Text = listViewItemEnumerable.Count().ToString();

}

#endregion

//////////////////////////////////////////////////////////////////////////////// Function

#region 항목 컬렉션 구하기 - GetItemCollection(itemCount)

/// <summary>

/// 항목 컬렉션 구하기

/// </summary>

/// <param name="itemCount">항목 수</param>

/// <returns>항목 컬렉션</returns>

private ObservableCollection<string> GetItemCollection(int itemCount)

{

ObservableCollection<string> collection = [];

for(int i = 0; i < itemCount; i++)

{

string item = (i % 2) == 0 ? $"{i} - Even" : $"{i} - Odd";

collection.Add(item);

}

return collection;

}

#endregion

}

TestProject.zip