[C#/WPF] UIElement 클래스 : DragEnter/GiveFeedback/DragOver/Drop/DragLeave 이벤트를 사용해 드래그하기

TestProject.zip

다운로드

▶ MainWindow.xaml

<Window x:Class="TestProject.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Width="800"
    Height="600"
    Title="UIElement 클래스 : DragEnter/GiveFeedback/DragOver/Drop/DragLeave 이벤트를 사용해 드래그하기"
    FontFamily="나눔고딕코딩"
    FontSize="16">
    <Grid>
        <StackPanel
            HorizontalAlignment="Center"
            VerticalAlignment="Center"
            Margin="10">
            <Ellipse Name="ellipse1"
                Margin="10"
                Width="50"
                Height="50"
                Fill="Green"
                AllowDrop="True" />
            <Ellipse Name="ellipse2"
                Margin="10"
                Width="50"
                Height="50"
                Fill="Red"
                AllowDrop="True" />
            <RichTextBox Name="richTextBox"
                Margin="10"
                AllowDrop="True" />
        </StackPanel>
    </Grid>
</Window>

 

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▶ MainWindow.xaml.cs

using System;
using System.IO;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Shapes;

namespace TestProject
{
    /// <summary>
    /// 메인 애플리케이션
    /// </summary>
    public partial class MainWindow : Window
    {
        //////////////////////////////////////////////////////////////////////////////////////////////////// Field
        ////////////////////////////////////////////////////////////////////////////////////////// Private

        #region Field

        /// <summary>
        /// 이전 브러시
        /// </summary>
        private Brush previousBrush = null;

        #endregion

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

        #region 생성자 - MainWindow()

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

            this.ellipse1.MouseMove    += ellipse_MouseMove;
            this.ellipse1.DragEnter    += ellipse_DragEnter;
            this.ellipse1.GiveFeedback += ellipse_GiveFeedback;
            this.ellipse1.DragOver     += ellipse_DragOver;
            this.ellipse1.Drop         += ellipse_Drop;
            this.ellipse1.DragLeave    += ellipse_DragLeave;

            this.ellipse2.MouseMove    += ellipse_MouseMove;
            this.ellipse2.DragEnter    += ellipse_DragEnter;
            this.ellipse2.GiveFeedback += ellipse_GiveFeedback;
            this.ellipse2.DragOver     += ellipse_DragOver;
            this.ellipse2.Drop         += ellipse_Drop;
            this.ellipse2.DragLeave    += ellipse_DragLeave;

            this.richTextBox.AddHandler(RichTextBox.DragOverEvent, new DragEventHandler(richTextBox_DragOver), true);
            this.richTextBox.AddHandler(RichTextBox.DropEvent    , new DragEventHandler(richTextBox_Drop    ), true);

        }

        #endregion

        //////////////////////////////////////////////////////////////////////////////////////////////////// Method
        ////////////////////////////////////////////////////////////////////////////////////////// Private

        #region 타원 마우스 이동시 처리하기 - ellipse_MouseMove(sender, e)

        /// <summary>
        /// 타원 마우스 이동시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void ellipse_MouseMove(object sender, MouseEventArgs e)
        {
            Ellipse ellipse = sender as Ellipse;

            if(ellipse != null && e.LeftButton == MouseButtonState.Pressed)
            {
                DragDrop.DoDragDrop(ellipse, ellipse.Fill.ToString(), DragDropEffects.Copy);
            }
        }

        #endregion
        #region 타원 드래그 진입시 처리하기 - ellipse_DragEnter(sender, e)

        /// <summary>
        /// 타원 드래그 진입시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void ellipse_DragEnter(object sender, DragEventArgs e)
        {
            Ellipse ellipse = sender as Ellipse;

            if(ellipse != null)
            {
                this.previousBrush = ellipse.Fill;
                
                if(e.Data.GetDataPresent(DataFormats.StringFormat))
                {
                    string dataString = (string)e.Data.GetData(DataFormats.StringFormat);

                    BrushConverter converter = new BrushConverter();

                    if(converter.IsValid(dataString))
                    {
                        Brush newBrush = (Brush)converter.ConvertFromString(dataString);

                        ellipse.Fill = newBrush;
                    }
                }
            }
        }

        #endregion
        #region 타원 피드백 주기 - ellipse_GiveFeedback(sender, e)

        /// <summary>
        /// 타원 피드백 주기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void ellipse_GiveFeedback(object sender, GiveFeedbackEventArgs e)
        {
            try
            {
                if(e.Effects.HasFlag(DragDropEffects.Move))
                {
                    Mouse.SetCursor(Cursors.ArrowCD);
                }
                else if(e.Effects.HasFlag(DragDropEffects.Copy))
                {
                    Mouse.SetCursor(Cursors.Wait);
                }
            }
            catch(Exception)
            {
                e.UseDefaultCursors = true;
            }

            e.Handled = true;
        }

        #endregion
        #region 타원 드래그 OVER 처리하기 - ellipse_DragOver(sender, e)

        /// <summary>
        /// 타원 드래그 OVER 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void ellipse_DragOver(object sender, DragEventArgs e)
        {
            e.Effects = DragDropEffects.None;

            if(e.Data.GetDataPresent(DataFormats.StringFormat))
            {
                string dataString = (string)e.Data.GetData(DataFormats.StringFormat);

                BrushConverter converter = new BrushConverter();

                if(converter.IsValid(dataString))
                {
                    e.Effects = DragDropEffects.Copy | DragDropEffects.Move;
                }
            }
        }

        #endregion
        #region 타원 드래그 DROP 처리하기 - ellipse_Drop(sender, e)

        /// <summary>
        /// 타원 드래그 DROP 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void ellipse_Drop(object sender, DragEventArgs e)
        {
            Ellipse ellipse = sender as Ellipse;

            if(ellipse != null)
            {
                if(e.Data.GetDataPresent(DataFormats.StringFormat))
                {
                    string dataString = (string)e.Data.GetData(DataFormats.StringFormat);

                    BrushConverter converter = new BrushConverter();

                    if(converter.IsValid(dataString))
                    {
                        Brush newBrush = (Brush)converter.ConvertFromString(dataString);

                        ellipse.Fill = newBrush;
                    }
                }
            }
        }

        #endregion
        #region 타원 드래그 이탈시 처리하기 - ellipse_DragLeave(sender, e)

        /// <summary>
        /// 타원 드래그 이탈시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void ellipse_DragLeave(object sender, DragEventArgs e)
        {
            Ellipse ellipse = sender as Ellipse;

            if(ellipse != null)
            {
                ellipse.Fill = this.previousBrush;
            }
        }

        #endregion
        #region 리치 텍스트 박스 드래그 OVER 처리하기 - richTextBox_DragOver(sender, e)

        /// <summary>
        /// 리치 텍스트 박스 드래그 OVER 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void richTextBox_DragOver(object sender, DragEventArgs e)
        {
            if(e.Data.GetDataPresent(DataFormats.FileDrop))
            {
                e.Effects = DragDropEffects.All;
            }
            else
            {
                e.Effects = DragDropEffects.None;
            }

            e.Handled = false;
        }

        #endregion
        #region 리치 텍스트 박스 드래그 DROP 처리하기 - richTextBox_Drop(sender, e)

        /// <summary>
        /// 리치 텍스트 박스 드래그 DROP 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void richTextBox_Drop(object sender, DragEventArgs e)
        {
            if(e.Data.GetDataPresent(DataFormats.FileDrop))
            {
                string[] filePathArray = (string[])e.Data.GetData(DataFormats.FileDrop);

                string dataFormat = DataFormats.Rtf;

                if(e.KeyStates == DragDropKeyStates.ShiftKey)
                {
                    dataFormat = DataFormats.Text;
                }

                TextRange  textRange;
                FileStream fileStream;

                if(File.Exists(filePathArray[0]))
                {
                    try
                    {
                        textRange = new TextRange
                        (
                            this.richTextBox.Document.ContentStart,
                            this.richTextBox.Document.ContentEnd
                        );

                        fileStream = new FileStream(filePathArray[0], FileMode.OpenOrCreate);

                        textRange.Load(fileStream, dataFormat);

                        fileStream.Close();
                    }
                    catch(Exception)
                    {
                        MessageBox.Show("File could not be opened. Make sure the file is a text file.");
                    }
                }
            }
        }

        #endregion
    }
}