ICODEBROKER

<Window x:Class="TestProject.MainWindow"

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

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

    xmlns:local="clr-namespace:TestProject"

    Width="800"

    Height="600"

    Title="LinearGradientBrush 클래스 : 오프셋 값을 사용해 색상 구하기"

    FontFamily="나눔고딕코딩"

    FontSize="16">

    <Grid>

        <StackPanel

            HorizontalAlignment="Center"

            VerticalAlignment="Center">

            <Rectangle Name="sourceRectangle"

                Width="400"

                Height="50">

                <Rectangle.Fill>

                    <LinearGradientBrush x:Name="sourceBrush"

                        StartPoint="0 0.5" EndPoint="1 0.5">

                        <GradientStop Offset="0"   Color="Blue"   />

                        <GradientStop Offset="0.5" Color="Green" />

                        <GradientStop Offset="1"   Color="Yellow" />

                    </LinearGradientBrush>

                </Rectangle.Fill>

            </Rectangle>

            <DockPanel LastChildFill="False">

                <TextBlock Name="rectangleFirstTextBlock" DockPanel.Dock="Left"

                    Width="10"

                    Text="0" />

                <TextBlock Name="rectangleLastTextBlock" DockPanel.Dock="Right"

                    Text="{Binding ElementName=sourceRectangle, Path=ActualWidth}" />

            </DockPanel>

            <StackPanel Name="mousePointStackPanel"

                HorizontalAlignment="Center"

                Orientation="Horizontal"

                Visibility="Collapsed">

                <TextBlock Text="마우스 좌표 : " />

                <TextBlock Name="mousePointTextBlock" />

            </StackPanel>

            <Rectangle Name="targetRectangle"

                Margin="0 30 0 0"

                Width="50"

                Height="50"

                Stroke="Black"

                StrokeThickness="1">

                <Rectangle.Fill>

                    <SolidColorBrush x:Name="targetBrush"

                        Color="Blue" />

                </Rectangle.Fill>

            </Rectangle>

            <TextBlock Name="targetColorTextBlock"

                Margin="0 10 0 0"

                HorizontalAlignment="Center" />

        </StackPanel>

    </Grid>

</Window>

using System;

using System.Linq;

using System.Windows;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Shapes;

namespace TestProject

{

    /// <summary>

    /// 메인 윈도우

    /// </summary>

    public partial class MainWindow : Window

    {

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

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

        #region 생성자 - MainWindow()

        /// <summary>

        /// 생성자

        /// </summary>

        public MainWindow()

        {

            InitializeComponent();

            this.sourceRectangle.MouseEnter += sourceRectangle_MouseEnter;

            this.sourceRectangle.MouseMove  += sourceRectangle_MouseMove;

            this.sourceRectangle.MouseLeave += sourceRectangle_MouseLeave;

        }

        #endregion

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

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

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

        #region 소스 사각형 마우스 진입시 처리하기 - sourceRectangle_MouseEnter(sender, e)

        /// <summary>

        /// 소스 사각형 마우스 진입시 처리하기

        /// </summary>

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

        /// <param name="e">이벤트 인자</param>

        private void sourceRectangle_MouseEnter(object sender, MouseEventArgs e)

        {

            this.mousePointStackPanel.Visibility = Visibility.Visible;

        }

        #endregion

        #region 소스 사각형 마우스 이동시 처리하기 - sourceRectangle_MouseMove(sender, e)

        /// <summary>

        /// 소스 사각형 마우스 이동시 처리하기

        /// </summary>

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

        /// <param name="e">이벤트 인자</param>

        private void sourceRectangle_MouseMove(object sender, MouseEventArgs e)

        {

            Rectangle rectangle = sender as Rectangle;

            Point mousePoint = e.GetPosition(rectangle);

            double rectangleWidth = rectangle.ActualWidth;

            double offset = mousePoint.X / rectangleWidth;

            Color color = GetColor(this.sourceBrush, offset);

            this.targetBrush.Color = color;

            this.targetColorTextBlock.Text = color.ToString();

            if(this.mousePointStackPanel.Visibility == Visibility.Visible)

            {

                this.mousePointTextBlock.Text = mousePoint.ToString();

            }

        }

        #endregion

        #region 소스 사각형 마우스 이탈시 처리하기 - sourceRectangle_MouseLeave(sender, e)

        /// <summary>

        /// 소스 사각형 마우스 이탈시 처리하기

        /// </summary>

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

        /// <param name="e">이벤트 인자</param>

        private void sourceRectangle_MouseLeave(object sender, MouseEventArgs e)

        {

            this.mousePointStackPanel.Visibility = Visibility.Collapsed;

            this.targetBrush.Color = Colors.Transparent;

            this.targetColorTextBlock.Text = Colors.Transparent.ToString();

        }

        #endregion

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

        #region 색상 구하기 - GetColor(brush, offset)

        /// <summary>

        /// 색상 구하기

        /// </summary>

        /// <param name="brush">선형 그라디언트 브러시</param>

        /// <param name="offset">오프셋</param>

        /// <returns>색상</returns>

        private Color GetColor(LinearGradientBrush brush, double offset)

        {

            GradientStopCollection gradientStopCollection = brush.GradientStops;

            GradientStop[] gradientStopArray = gradientStopCollection.OrderBy(x => x.Offset).ToArray();

            if(offset <= 0)

            {

                return gradientStopArray[0].Color;

            }

            if(offset >= 1)

            {

                return gradientStopArray[gradientStopArray.Length - 1].Color;

            }

            GradientStop firstStop = gradientStopArray[0];

            GradientStop lastStop  = null;

            foreach(GradientStop stop in gradientStopArray)

            {

                if(stop.Offset >= offset)

                {

                    lastStop = stop;

                    break;

                }

                firstStop = stop;

            }

            offset = Math.Round((offset - firstStop.Offset) / (lastStop.Offset - firstStop.Offset), 2);

            byte alpha = (byte)((lastStop.Color.A - firstStop.Color.A) * offset + firstStop.Color.A);

            byte red   = (byte)((lastStop.Color.R - firstStop.Color.R) * offset + firstStop.Color.R);

            byte green = (byte)((lastStop.Color.G - firstStop.Color.G) * offset + firstStop.Color.G);

            byte blue  = (byte)((lastStop.Color.B - firstStop.Color.B) * offset + firstStop.Color.B);

            return Color.FromArgb(alpha, red, green, blue);

        }

        #endregion

    }

}