C# 实现Bezier曲线（vs2008）

 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 doBezier

 {

     public partial class Form1 : Form

     {

         PointF[] p = new PointF[];   //存储控制点坐标

         int count;                    //记录已输入的控制点个数

         Graphics g;                  //GDI 对象

         public Form1()

         {

             InitializeComponent();

             g = CreateGraphics();

             count = ;

         }

         private void Form1_Load(object sender, EventArgs e)

         {

         }

         private void Form1_MouseClick(object sender, MouseEventArgs e)

         {

             if (e.Button == MouseButtons.Left)

             {

                 if (count == )      //如果输入的是第一个点，先清空窗口

                     g.Clear(BackColor);

                 g.FillRectangle(Brushes.Red, e.X - , e.Y - , , );  //输出一个标记

                 p[count] = new PointF(e.X, e.Y);                 //存储

                 count ;                                    //记录输入控制点个数

                 return;

             }

             else

             {

                 PointF q1 = new PointF();

                 PointF q2 = new PointF();

                 double u;

                 for (int i = ; i <= ; i )//生成100个点并连成折线

                 {

                     u = (double)i / 100.0;

                     if (i == )

                     {

                         q1 = deCasteljau(u);

                     }

                     else

                     {

                         q2 = deCasteljau(u);

                         g.DrawLine(Pens.Black, q1, q2);

                         q1.X = q2.X;

                         q1.Y = q2.Y;

                     }

                 }

                 count = ;

                 return;

             }

         }

         PointF deCasteljau(double u)   //曲线参数为u，函数返回一个二维点 

         {

             int i, k;

             //以下将控制点数组p[]，复制到数组q[]

             PointF[] q = new PointF[];

             for (i = ; i < count; i )

             {

                 q[i].X = p[i].X;

                 q[i].Y = p[i].Y;

             }

             //以下用de Casteljau割角算法计算bezier曲线上参数点u对应的x,y，

             //计算完成后，结果存储在q[0]

             for (k = ; k < count; k )

                 for (i = ; i < count - k; i )

                 {

                     q[i].X = (float)(1.0 - u) * q[i].X   (float)u * q[i   ].X;

                     q[i].Y = (float)(1.0 - u) * q[i].Y   (float)u * q[i   ].Y;

                 }

             return new PointF(q[].X, q[].Y);

         }

         private void Form1_Paint(object sender, PaintEventArgs e)

         {

         }

     }

 }