test3.aspx.cs

互联网程序设计的课程

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Text;

public partial class backup_test3 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string codes = CreateCode(6);
           CreateImage(codes);
        Session["CheckCodes"] = codes;
    
    }
    private string CreateCode(int numbers)
    {
        string strs = "0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z";
        string[] chars = strs.Split(',');

        Random ran = new Random();
        string strCode = "";
        for (int i = 0; i < numbers; i++)
        {
            int j = ran.Next(0, chars.Length);
            strCode += chars[j];
        }

        return strCode;
    }
    private void CreateImage(string strCode)
    {
        Bitmap bp = new Bitmap(strCode.Length * 16, 28);
        Graphics g = Graphics.FromImage(bp);
        g.Clear(Color.White);

        Pen silverPen = new Pen(Color.Silver);

        //随机画25条背景线背景
        Random ran = new Random();
        for (int i = 0; i < 25; i++)
        {
            int x1 = ran.Next(bp.Width);
            int y1 = ran.Next(bp.Height);
            int x2 = ran.Next(bp.Width);
            int y2 = ran.Next(bp.Height);

            g.DrawLine(silverPen, x1, y1, x2, y2);
        }
        //画随机验证码
        LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, bp.Width, bp.Height), Color.Green, Color.Blue, 2);
        Font font = new Font("Arial", 18, FontStyle.Bold | FontStyle.Italic);
        g.DrawString(strCode, font, brush, 0, 0);
        //设置100个点的颜色为银色
        for (int i = 0; i < 100; i++)
        {
            int x = ran.Next(bp.Width);
            int y = ran.Next(bp.Height);
            bp.SetPixel(x, y, Color.Silver);
        }
        //为验证码添加一个银色的边框
        g.DrawRectangle(silverPen, 0, 0, bp.Width - 1, bp.Height - 1);
        //定义一个内存流 
        System.IO.MemoryStream ms = new System.IO.MemoryStream();
        //将我们“画”的验证码图片存放在刚刚创建的内存流中  并指定图片保存的格式(后缀)
        bp.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
        //清除缓冲区的内容
        Response.ClearContent();
        //设置输出流的类型
        Response.ContentType = "image/gif";
        //ms.ToArray()将内存流转换为二进制数组
        Response.BinaryWrite(ms.ToArray());//这时候 图片是以流的形式存放(写入)在http输出流中  

        g.Dispose();
        bp.Dispose();
    }
}