验证码

最新推荐文章于 2025-07-22 00:16:16 发布

转载最新推荐文章于 2025-07-22 00:16:16 发布 · 481 阅读

文章标签：

#random #string #xhtml #server #object #class

添加验证码，单击刷新并验证

上

============================================

第一步:添加一个页面,页面代码如下:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="CheckCode.aspx.cs" Inherits="CheckCode" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

</head>

<body>

<div>

</div>

</form>

</body>

</html>

第二步:添加页面的cs代码:

using System;

using System.Collections;

using System.Configuration;

using System.Data;

using System.Linq;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.HtmlControls;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Xml.Linq;

using System.Drawing;

//这是一个生成验证码的网页

public partial class CheckCode : System.Web.UI.Page

{

private string GenerateCheckCode()

{

int num;

char code;

string checkCode = string.Empty;

Random random = new Random();

for (int i = 0; i < 6; i++)//循环次数决定验证码的位数

{

num = random.Next();

if (num % 2 == 0)

{

code = (char)('0' + (char)(num % 10));

}

else

{

code = (char)('A' + (char)(num % 26));

}

checkCode += code.ToString();

}

Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));

return checkCode;

}

protected void Page_Load(object sender, EventArgs e)

{

CreateCheckCodeImg(GenerateCheckCode());

}

private void CreateCheckCodeImg(string checkCode)

{

if (checkCode == null || checkCode.Trim() == String.Empty)

return;

Bitmap img = new Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);

Graphics g = Graphics.FromImage(img);

try

{

Random random = new Random();

g.Clear(Color.White);

//画图片的背景线

for (int i = 0; i < 2; i++)

{

int x1 = random.Next(img.Width);

int x2 = random.Next(img.Width);

int y1 = random.Next(img.Width);

int y2 = random.Next(img.Width);

g.DrawLine(new Pen(Color.Black), x1, y1, x2, y2);

}

//画出指定的字符

Font font = new Font("Arial", 12, (FontStyle.Bold));

System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, img.Width, img.Height), Color.Blue, Color.Red, 1.2f, true);

g.DrawString(checkCode, font, brush, 2, 2);

//画图片的前景噪点

for (int i = 0; i < 100; i++)

{

int x = random.Next(img.Width);

int y = random.Next(img.Height);

img.SetPixel(x, y, Color.FromArgb(random.Next()));

}

g.DrawRectangle(new Pen(Color.Silver),0,0,img.Width-1,img.Height-1);

System.IO.MemoryStream ms=new System.IO.MemoryStream();

img.Save(ms,System.Drawing.Imaging.ImageFormat.Gif);

Response.ClearContent();

Response.ContentType="image/Gif";

Response.BinaryWrite(ms.ToArray());

}

finally

{

g.Dispose();

img.Dispose();

}

第三步:在需要验证码的网页引用产生验证码的网页:

在你需要调用验证码的网页中添加一个<img>标签,将img标签的src设置成刚刚新添加的那个aspx!比如<img alt="验证码" src="CkeckCode.aspx"></img>

下面是刷新功能:

你可以把img标签和一个linkbutton一起加入到updatepanel中,然后生成一个linkbutton的click事件,不用在里面写任何代码的,就可以达到刷新验证码的效果了.

最后一步:验证验证码:

在验证页面里添加以下代码:

HttpCookie cookie = Request.Cookies["CheckCode"];

if (cookie.Value == tbYanZM.Text)

{

Response.Write("...验证码正确");

}