动态加载验证码

来源：互联网发布：抢车票软件编辑：程序博客网时间：2024/06/06 08:24

1.创建一般应用程序ashx

<%@ WebHandler Language="C#" Class="YZM" %>using System;using System.Web;public class YZM : IHttpHandler,System .Web.SessionState .IRequiresSessionState{        public void ProcessRequest (HttpContext context) {       //动态生成图片        context.Response.ContentType = "image/JPEG";        using (System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(100, 30))        {            using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap))            {                /*                 g.DrawString("验证码", new System.Drawing.Font("宋体", 10), System.Drawing.Brushes .Red , new System.Drawing.PointF(0, 0));                 bitmap .Save (context .Response .OutputStream ,System .Drawing.Imaging.ImageFormat .Jpeg) ;                 */                //动态产生随机数                Random rand = new Random();                int code = rand.Next();                string strCode = code.ToString();                HttpContext.Current.Session["Code"] = strCode;                g.DrawString(strCode, new System.Drawing.Font("宋体", 12), System.Drawing.Brushes.Green, new System.Drawing.PointF(0, 0));                bitmap.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);            }        }    }       public bool IsReusable {        get {            return false;        }    }    }

2.在aspx中调用Session中存储的验证码

using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;public partial class 验证码 : System.Web.UI.Page{    protected void Page_Load(object sender, EventArgs e)    {    }    protected void Button1_Click(object sender, EventArgs e)    {        string yzm = Convert.ToString(Session ["Code"]);        Response.Write(yzm);        if (yzm==TextBox1 .Text )        {            Response.Write("验证码正确");        }        else        {            Response.Write("验证码不正确，请重新输入");            TextBox1.Text = "";        }    }}