[C#/WINFORM] Graphics 클래스 : DrawCurve 메소드를 사용해 곡선 그리기

TestProject.zip

다운로드

▶ MainForm.cs

using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

namespace TestProject
{
    /// <summary>
    /// 메인 폼
    /// </summary>
    public partial class MainForm : Form
    {
        //////////////////////////////////////////////////////////////////////////////////////////////////// Constructor
        ////////////////////////////////////////////////////////////////////////////////////////// Public

        #region Field

        /// <summary>
        /// 포인트 리스트
        /// </summary>
        private List<Point> pointList = new List<Point>();

        /// <summary>
        /// 텐션
        /// </summary>
        private float tension = 0.5f;

        /// <summary>
        /// 그리기 여부
        /// </summary>
        private bool isDrawing = true;

        #endregion

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

        #region 생성자 - MainForm()

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

            this.tensionScrollBar.Scroll     += tensionScrollBar_Scroll;
            this.canvasPictureBox.Paint      += canvasPictureBox_Paint;
            this.canvasPictureBox.MouseClick += canvasPictureBox_MouseClick;
        }

        #endregion

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

        #region 텐션 스크롤바 스크롤시 처리하기 - tensionScrollBar_Scroll(sender, e)

        /// <summary>
        /// 텐션 스크롤바 스크롤시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void tensionScrollBar_Scroll(object sender, ScrollEventArgs e)
        {
            this.tension = this.tensionScrollBar.Value / 10f;

            this.tensionLabel.Text = tension.ToString();

            this.canvasPictureBox.Refresh();
        }

        #endregion
        #region 캔버스 픽처 박스 마우스 클릭시 처리하기 - canvasPictureBox_MouseClick(sender, e)

        /// <summary>
        /// 캔버스 픽처 박스 마우스 클릭시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void canvasPictureBox_MouseClick(object sender, MouseEventArgs e)
        {
            if(this.isDrawing)
            {
                if(e.Button == MouseButtons.Left)
                {
                    this.pointList.Add(e.Location);
                }
                else
                {
                    this.isDrawing = false;
                }
            }
            else
            {
                this.isDrawing = true;

                this.pointList = new List<Point>();

                this.pointList.Add(e.Location);
            }

            this.canvasPictureBox.Refresh();
        }

        #endregion
        #region 캔버스 픽처 박스 페인트시 처리하기 - canvasPictureBox_Paint(sender, e)

        /// <summary>
        /// 캔버스 픽처 박스 페인트시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void canvasPictureBox_Paint(object sender, PaintEventArgs e)
        {
            e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;

            if(this.pointList.Count > 1)
            {
                using(Pen pen = new Pen(Color.Blue))
                {
                    if(this.isDrawing)
                    {
                        pen.DashPattern = new float[] { 5, 5 };
                    }

                    e.Graphics.DrawCurve(pen, this.pointList.ToArray(), this.tension);
                }
            }

            if(this.isDrawing && (this.pointList.Count > 0))
            {
                const int SIDE = 4;

                foreach(Point point in this.pointList)
                {
                    Rectangle rectangle = new Rectangle
                    (
                        point.X - SIDE,
                        point.Y - SIDE,
                        2 * SIDE,
                        2 * SIDE
                    );

                    e.Graphics.FillRectangle(Brushes.White, rectangle);

                    e.Graphics.DrawRectangle(Pens.Black, rectangle);
                }
            }
        }

        #endregion
    }
}