C# 网页画图

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;

public partial class _Default : System.Web.UI.Page
{
    int h = 1000;
    int w = 1000;
    protected void Page_Load(object sender, EventArgs e)
    {
        Bitmap img = new Bitmap(h, w);//创建Bitmap对象
        MemoryStream stream = draw();

        img.Save(stream, ImageFormat.Jpeg);          //保存绘制的图片
        Response.Clear();
        Response.ContentType = "image/jpeg";
        Response.BinaryWrite(stream.ToArray());
    }

    public MemoryStream draw()
    {
        string[] Words = {"壹","贰","叁","肆","伍","陆"};
        Bitmap img = new Bitmap(h, w);//创建Bitmap对象
        Graphics g = Graphics.FromImage(img);//创建Graphics对象
        g.DrawRectangle(new Pen(Color.White, img.Height), 2, 2, img.Width - 2, img.Height - 2); //矩形 底色

        ArrayList coordinate = getXY(Words.Length,img.Height,img.Width);
        ArrayList Radius = new ArrayList();

        var R = new Random();
        Color Mycolor = Color.FromArgb(R.Next(100, 150), R.Next(255), R.Next(255), R.Next(255));

        Font font = new Font("Arial", 20);// 字体
        LinearGradientBrush font_brush = new LinearGradientBrush(new Rectangle(0, 0, img.Width, img.Height), Color.Black, Color.Black, 1.2F, true);

        int j = 0;
        //画圆 写字
        foreach (Point p in coordinate)
        {
            int r = R.Next(20, 40);
            Radius.Add(r);
            SolidBrush bush = new SolidBrush(Mycolor);
            g.FillEllipse(bush, p.X - r, p.Y - r, 2*r, 2*r);//画填充椭圆的方法，x坐标、y坐标、宽、高：

            g.DrawString(Words[j++], font, font_brush, p); // 标记
        }

        //连线
        var penColor = Color.FromArgb(140, R.Next(255), R.Next(255), R.Next(255));
        for (int i = 1; i < coordinate.Count; i++) 
        {
            Pen pen = new Pen(penColor, 2);
            g.DrawLine(pen, (Point)coordinate[0], (Point)coordinate[i]);
        }
        
        MemoryStream stream = new MemoryStream();   //保存绘制的图片
        img.Save(stream, ImageFormat.Jpeg);          //保存绘制的图片
        return stream;
    }

    private ArrayList getXY(int len, int h, int w) 
    {
        ArrayList al = new ArrayList();
        double d = 50.0;
        var R = new Random();
        int h1 = (int)(0.1 * h);
        int h2 = (int)(0.9 * h);
        int w1 = (int)(0.1 * w);
        int w2 = (int)(0.9 * w);

        while (al.Count < len) 
        {
            Point p = new Point(R.Next(h1,h2), R.Next(w1,w2));
            bool Add = true;
            foreach (Point q in al) 
            {
                if (Dist(p, q) < d)
                {
                    Add = false;
                    break;
                }
            }
            if (Add)
                al.Add(p);

        }

        return al;
    }

    private double Dist(Point p1,Point p2) 
    {
        return Math.Sqrt(Math.Abs(p1.X - p2.X) * Math.Abs(p1.X - p2.X) + Math.Abs(p1.Y - p2.Y) * Math.Abs(p1.Y - p2.Y));
    }
}