using System;
using System.Web;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Web.SessionState;
namespace Web.handler
{
/// <summary>
/// WaterMark 的摘要说明
/// </summary>
public class WaterMark : IHttpHandler, IRequiresSessionState // 要使用session必须实现该接口,记得要导入System.Web.SessionState命名空间
{
public void ProcessRequest(HttpContext context)
{
string checkCode = GenCode(5); // 产生5位随机字符
context.Session["Code"] = checkCode; //将字符串保存到Session中,以便需要时进行验证
System.Drawing.Bitmap image = new System.Drawing.Bitmap(70, 22);
Graphics g = Graphics.FromImage(image);
try
{
//生成随机生成器
Random random = new Random();
//清空图片背景色
g.Clear(Color.White);
// 画图片的背景噪音线
int i;
for (i = 0; i < 25; i++)
{
int x1 = random.Next(image.Width);
int x2 = random.Next(image.Width);
int y1 = random.Next(image.Height);
int y2 = random.Next(image.Height);
g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
}
Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold));
System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0,
image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2F, true);
g.DrawString(checkCode, font, brush, 2, 2);
//画图片的前景噪音点
g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
System.IO.MemoryStream ms = new System.IO.MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
context.Response.ClearContent();
context.Response.ContentType = "image/Gif";
context.Response.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
/// <summary>
/// 产生随机字符串
/// </summary>
/// <param name="num">随机出几个字符</param>
/// <returns>随机出的字符串</returns>
private string GenCode(int num)
{
//验证码中出现的字符
string str = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; //str中的值就是将来会在验证码中出现的字符
char[] chastr = str.ToCharArray();
string code = "";
Random rd = new Random();
int i;
for (i = 0; i < num; i++)
{
//code += source[rd.Next(0, source.Length)];
code += str.Substring(rd.Next(0, str.Length), 1);
}
return code;
}
public bool IsReusable
{
get
{
return false;
}
}
}
}
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Login.aspx.cs" Inherits="nwessystem.Login" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www./TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www./1999/xhtml"> <head runat="server"> <title>登录窗体</title> <link href="../css/login.css" rel="stylesheet" type="text/css" /> <script language="javascript" type="text/javascript"> //刷新验证码的js函数 function changeCode() { var imgNode = document.getElementById("vimg"); //重新加载验证码,达到刷新的目的 imgNode.src = "../handler/WaterMark.ashx?t=" + (new Date()).valueOf(); // 这里加个时间的参数是为了防止浏览器缓存的问题 } </script> </head> <body> <p>验证码:<img src="../handler/WaterMark.ashx" id="vimg" alt="点击刷新验证码" onclick="changeCode() " /><asp:TextBox ID="txtCode" runat="server" CssClass="txtcode"></asp:TextBox></p> </body> </html>
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using BLL; namespace nwessystem { public partial class Login : System.Web.UI.Page { protected void btnLogin_Click(object sender, EventArgs e) { //检验验证码部分 string code = txtCode.Text.Trim().ToUpper(); string rightCode = Session["Code"].ToString(); //判断验证码是否正确 if (code != rightCode) { //验证码输入错误! Page.ClientScript.RegisterStartupScript(Page.GetType(), "message", "<script language='javascript' defer>alert('验证码错误!');</script>"); return; } //检验用户名和密码部分 string name=txtName.Text.Trim(); string pwd=txtPassword.Text.Trim(); bool b = LoginManager.Login(name, pwd); if (b) { //登录成功 Page.ClientScript.RegisterStartupScript(Page.GetType(), "message", "<script language='javascript' defer>alert('登录成功!');</script>"); } else { //登录失败 Page.ClientScript.RegisterStartupScript(Page.GetType(), "message", "<script language='javascript' defer>alert('登录失败,用户名或密码错误!');</script>"); } } } } 好了,通过上面简单的代码就可以实现验证码的生成与验证了。代码里注释很详细了,相信不用我再写多余的说明,大家也都可以看懂。如果还是不懂欢迎在下方留言。博客水平有限,希望各位多多指正! |
|
来自: 昵称10504424 > 《Js》