[WPF] DependencyProperty 사용방법

1. DependencyProperty 란?

 

DependencyProperty 란 프로퍼티 값이 변경되었을 때 자동으로 어떤 일을 처리하게 할 수 있게 해주는 것입니다.

스타일링, 데이터 바인딩, 애니메이션 등 WPF 주요 부분에 사용합니다.

 

DependencyProperty를  사용하면 엘리먼트를 사용하는 시점에 프로퍼티 값이 결정되고, Static 변수이기 때문에 메모리 절약에 효과적입니다. 그리고 프로퍼티를 구현할 때 필요한 많은 코드를 표준화할 수 있습니다.

 

2. 예제

예제로는 UserControl에 DependencyProperty를 사용하겠습니다.

 

UserControl1.xaml

 

<UserControl x:Class="WpfTriggerAndCommand.UserControls.UserControl1"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:WpfTriggerAndCommand.UserControls"
             mc:Ignorable="d" 
             d:DesignHeight="150" d:DesignWidth="300" x:Name="root">
    <Grid>
        <StackPanel>
            <Label Content="{Binding LabelName,ElementName=root}"></Label>
            <Button Width="100" Command="{Binding MyCommand,ElementName=root}">버튼</Button>
        </StackPanel>
    </Grid>
</UserControl>

 

UserControl1.cs

 

using System;
using System.Collections.Generic;
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 WpfTriggerAndCommand.UserControls
{
    /// <summary>
    /// UserControl1.xaml에 대한 상호 작용 논리
    /// </summary>
    public partial class UserControl1 : UserControl
    {
        public UserControl1()
        {
            InitializeComponent();
        }

        //propdp 입력후 빠르게 탭 두번
        public string LabelName
        {
            get { return (string)GetValue(LabelNameProperty); }
            set { SetValue(LabelNameProperty, value); }
        }
               
        //아래는 의존속성을 추가해주는 코드. 차례대로 이름, 타입, 소유클래스, 기본값
        // Using a DependencyProperty as the backing store for LabelName.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty LabelNameProperty =
            DependencyProperty.Register("LabelName", typeof(string), typeof(UserControl1), new PropertyMetadata(string.Empty));



        public ICommand MyCommand
        {
            get { return (ICommand)GetValue(MyCommandProperty); }
            set { SetValue(MyCommandProperty, value); }
        }

        // Using a DependencyProperty as the backing store for MyCommand.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty MyCommandProperty =
            DependencyProperty.Register("MyCommand", typeof(ICommand), typeof(UserControl1));




    }
}

 

MainWindow.xaml

<Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfTriggerAndCommand"
        xmlns:UserControls="clr-namespace:WpfTriggerAndCommand.UserControls" x:Class="WpfTriggerAndCommand.MainWindow"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <StackPanel>
            <ProgressBar Height="20" Value="{Binding ProgressValue}"/>
            <TextBox x:Name="textBox1"/>
            <Button Content="버튼" Command="{Binding Command}" CommandParameter="{Binding Text, ElementName=textBox1}"/>
            <!--LabelName,MyCommand는 유저컨트롤에서 지정한 변수이름 -->
            <UserControls:UserControl1 Width="300" Height="150" LabelName="내가 생성한 라벨" MyCommand="{Binding Command}"/>
        </StackPanel>
    </Grid>
</Window>