C# 绘制贝塞尔曲线 示例源码

【实例截图】

【核心代码】

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace DrawBezier
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            MyGraphic = this.CreateGraphics();
        }

        int LinesCount = 0;

        Graphics MyGraphic;



        public PointF GetPoint(PointF[] MyPoints, double t)
        {
            LinesCount  ;
            int PCount = MyPoints.Length;
            PointF[] MyNewPoints = new PointF[PCount - 1];
            double Anothert = 1.0 - t;
            for (int i = 0; i < PCount - 1; i  )
            {
                MyNewPoints[i] = Add(Mutiply(Anothert, MyPoints[i]), Mutiply(t, MyPoints[i   1]));
            }
            if (MyNewPoints.Length > 1)
            {
                return (GetPoint(MyNewPoints, t));
            }
            else
            {
                LinesCount = 0;
                return MyNewPoints[0];
            }
        }

        /// <summary>
        /// double型数与点相乘生成新点
        /// </summary>
        /// <param name="t"></param>
        /// <param name="MyPoint"></param>
        /// <returns></returns>
        public static PointF Mutiply(double t, PointF MyPoint)
        {
            return (new PointF((float)(t * MyPoint.X), (float)(t * MyPoint.Y)));
        }

        /// <summary>
        /// 实现点的相加，生成新点
        /// </summary>
        /// <param name="LeftP"></param>
        /// <param name="RightP"></param>
        /// <returns></returns>
        public static PointF Add(PointF LeftP, PointF RightP)
        {
            return (new PointF((LeftP.X   RightP.X), LeftP.Y   RightP.Y));
        }



        private PointF[] MyBezierpoints = new PointF[] { new PointF(0, 0), new PointF(10, 20), new PointF(100, 10) };

        /// <summary>
        /// 绘制Bezier曲线
        /// </summary>
        /// <param name="MyDrawingPen"></param>
        /// <param name="Points"></param>
        private void DrawMyBezier(Pen MyDrawingPen, PointF[] Points)
        {
            Refresh();
            //int pointcount = AllMyPoints.Count;
            int PointCount = Points.Length;

            if (PointCount < 2)
            {
                throw new Exception("点数不够！");
            }

            for (int i = 0; i < Points.Length; i  )
            {
                //RectangleF MyRectangleF = new RectangleF(MyBezierpoints[i], new SizeF((float)5, (float)5));
                RectangleF MyRectangleF = new RectangleF(Points[i], new SizeF((float)5, (float)5));
                MyGraphic.DrawEllipse(new Pen(Color.DarkRed), MyRectangleF);
                MyDrawingPen = new Pen(Color.Blue);
                //MyGraphic.DrawLines(MyDrawingPen, MyBezierpoints);
                MyGraphic.DrawLines(MyDrawingPen, Points);
            }
            PointF LeftPoint = Points[0];
            PointF RightPoint = new PointF();
            double t = 0.0;
            double tAdd = 1.0 / (100 * PointCount);
            MyGraphic = this.CreateGraphics();
            int Result;
            bool SelectResult = int.TryParse("2", out Result);
            if (!SelectResult)
            {
                MyDrawingPen.Width = 1;
            }
            else
            {
                MyDrawingPen.Width = Result;
            }
            for (int i = 0; i < (100 * PointCount); i  )
            {
                RightPoint = GetPoint(Points, t);
                MyGraphic.DrawLine(MyDrawingPen, LeftPoint, RightPoint);
                LeftPoint = RightPoint;
                t  = tAdd;
            }
        }


        private void Draw_Click(object sender, EventArgs e)
        {
            DrawMyBezier(new Pen(Color.Black), MyBezierpoints);
        }
    }
}