验证码

生成验证码页面代码

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.Design;using System.Drawing.Drawing2D;using System.Drawing.Printing;using System.Drawing.Imaging;using System.IO;public partial class view_VailCode : System.Web.UI.Page{ private string CreateCheckCodeString() { //定义用于验证码的字符数组 char[] AllCheckCodeArray ={ '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','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'}; //定义验证码字符串 string randomcode = ""; Random rd = new Random(); //生成4位验证码字符串 for (int i = 0; i < 4; i++) randomcode += AllCheckCodeArray[rd.Next(AllCheckCodeArray.Length)]; return randomcode; } //生成验证码图片 protected void Page_Load(object sender, EventArgs e) { //定义图片的宽度 int ImageWidth = 55; //定义图片高度 int ImageHeigh = 22; //定义字体，用于绘制文字 Font font = new Font("Arial", 12, FontStyle.Bold); //定义画笔，用于绘制文字 Brush brush = new SolidBrush(Color.Black); //定义钢笔，用于绘制干扰线 Pen pen1 = new Pen(Color.FromArgb(255, 100, 100), 0);//这里也可以直接获得一个现有的color对象如：Color.Gold.我是为了美观所以定义和下面一样 Pen pen2 = new Pen(Color.FromArgb(255, 100, 100), 0);//这里根据ARGB值定义获得了一个color对象 //创建一个图像 Bitmap BitImage = new Bitmap(ImageWidth, ImageHeigh); //从图像获取一个绘画面 Graphics graphics = Graphics.FromImage(BitImage); //清除整个绘图画面并用颜色填充 graphics.Clear(ColorTranslator.FromHtml("#F0F0F0"));//这里从HTML代码获取color对象 //定义文字的绘制矩形区域 RectangleF rect = new RectangleF(5, 2, ImageWidth, ImageHeigh); //定义一个随机数对象，用于绘制干扰线 Random rand = new Random(); //生成两条横向的干扰线 for (int i = 0; i < 2; i++) { //定义起点 Point p1 = new Point(0, rand.Next(ImageHeigh)); //定义终点 Point p2 = new Point(ImageWidth, rand.Next(ImageHeigh)); //绘制直线 graphics.DrawLine(pen1, p1, p2); } //生成两条纵向的干扰线 for (int i = 0; i < 2; i++) { //定义起点 Point p1 = new Point(rand.Next(ImageWidth), 0); //定义终点 Point p2 = new Point(rand.Next(ImageWidth), ImageHeigh); //绘制直线 graphics.DrawLine(pen2, p1, p2); } //绘制验证码文字 graphics.DrawString(CreateCheckCodeString(), font, brush, rect); Session.Add("vail", CreateCheckCodeString()); //保存图片为gif格式 BitImage.Save(Response.OutputStream, ImageFormat.Gif); //释放对象 graphics.Dispose(); BitImage.Dispose(); }}

ValidateBase类

using System;using System.Data;using System.Configuration;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;namespace Security{ /// <summary> /// ValidateBase 底层页 /// </summary> public class ValidateBase : System.Web.UI.Page { public ValidateBase() { } /// <summary> /// 存放验证码值 /// </summary> public string strValidate { get { if (Session["ValidateCode"] != null) return Session["ValidateCode"].ToString(); else return ""; } set { Session["ValidateCode"] = value; } } /// <summary> /// 存放登入信息 /// </summary> public string strUser { get { if (Session["strUser"] != null) return Session["strUser"].ToString(); else return ""; } set { Session["strUser"] = value; } } }}

实例：

public partial class include_login : ValidateBase{ if (txtVail.Text == base.strValidate) { //……相关代码 }}