결합 속성(?) Attached Property

Dependency Property 중에 다른 하나인 Attached Property 를 정리해 봅니다.

1. Declare Attached Property Class

using System;

using System.Linq;

using System.Windows;

using System.Windows.Controls;

 

namespace SteveDependencyProperties.AttachedProperties

{

    /// <summary>

    /// AttachedProperty class declare

    /// </summary>

    public static class MyTestAttachedProperties

    {

        /// <summary>

        /// DependencyProperty.RegisterAttached

        /// </summary>

        public static readonly DependencyProperty ShowCommonWinodwButtonProperty =

            DependencyProperty.RegisterAttached(

            "ShowCommonWinodwButton",

            typeof(bool),

            typeof(MyTestAttachedProperties),

            new PropertyMetadata(false, Changed));

 

        /// <summary>

        /// Attached Property Call Back Event

        /// </summary>

        /// <param name="d"></param>

        /// <param name="e"></param>

        private static void Changed(DependencyObject d, DependencyPropertyChangedEventArgs e)

        {

            var button = d as Button;

            if (button == null) return;

 

            if(e.NewValue != null && (bool)e.NewValue)

            {

                button.Click += ButtonClick;

            }

            else

            {

                button.Click -= ButtonClick;

            }

        }

 

        /// <summary>

        /// Receive Event

        /// </summary>

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

        /// <param name="e"></param>

        private static void ButtonClick(object sender, RoutedEventArgs e)

        {

            MessageBox.Show("ShowCommonWinodwButtonAttachedProperty");

        }

 

        /// <summary>

        /// Attached Set Property

        /// </summary>

        /// <param name="element"></param>

        /// <param name="value"></param>

        public static void SetShowCommonWinodwButton(UIElement element, bool value)

        {

            element.SetValue(ShowCommonWinodwButtonProperty, value);

        }

 

        /// <summary>

        /// Attached Get Property

        /// </summary>

        /// <param name="element"></param>

        /// <returns></returns>

        public static bool GetShowCommonWinodwButton(UIElement element)

        {

            return (bool)element.GetValue(ShowCommonWinodwButtonProperty);

        }

    }

 

}

2. Using XAML

<Window x:Class="SteveDependencyProperties.MainWindow"

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

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

 xmlns:attachedDependency="clr-namespace:SteveDependencyProperties.AttachedProperties" <-(1)

        Title="MainWindow" Height="350" Width="525">

    <Grid>

        <WrapPanel>

            <TextBlock>MyTestDependency</TextBlock>

<TextBox Text=" and "></TextBox>

            <Button Content="Test Attached Property"                   attachedDependency:MyTestAttachedProperties.ShowCommonWinodwButton="true">  <-(2)

            </Button>

        </WrapPanel>

    </Grid>

</Window>

3. 정리

(1) 사용을 원하는 XAML에서 Attached Property 를 선언합니다.

(2) 버튼에 개발자가 선언한 Attached Property를 등록합니다. 이렇게 하면 자동으로 버튼 클릭 이벤트를 따로 선언하지 않고 MyTestAttachedProperties 에 있는 버튼 클릭 이벤트가 동작합니다.

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