use of image captcha
sows in textbox
make
default.aspx like this
make
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Simple Captcha Example</title>
<style type="text/css">
td
{
font-family:Tahoma;
font-size:11px;
background-color:#EEEEEE;
}
span
{
font-family:Tahoma;
font-size:14px;
color:Red;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<table width="500">
<tr>
<td colspan="3">
<span></span><asp:Label ID="lblMessage" runat="server"></asp:Label></span>
</td>
</tr>
<tr>
<td>Image Code</td>
<td colspan="2"><img src="Captcha.aspx" alt="Verification Code" /></td>
</tr>
<tr>
<td>Enter Code</td>
<td><asp:TextBox ID="txtCode" runat="server"></asp:TextBox></td>
<td><asp:Button ID="btnVerify" runat="server" onclick="btnVerify_Click"
Text="Verify" /></td>
</tr>
</table>
</div>
</form>
</body>
</html>
and do the following coding in .aspx
using System;
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;
public partial class _Default : System.Web.UI.Page
{
protected void btnVerify_Click(object sender, EventArgs e)
{
string user_code = txtCode.Text;
string captcha_code = Session["CAPTCHA_CODE"].ToString();
if (user_code != captcha_code)
{
lblMessage.Text = "Verification Failed.";
}
else
{
lblMessage.Text = "Verification Successful";
}
}
protected void Page_Load(object sender, EventArgs e)
{
}
}
now take another form named captcha and set html like this,
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Captcha.aspx.cs" Inherits="Captcha" %>
and do the following code ib capcha .aspx .cs like this,
using System;
using System.Collections;
using System.Configuration;
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.Drawing;
using System.Drawing.Drawing2D;
public partial class Captcha : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string strString = "abcdefghijklmnopqrstuvwxyz0123456789";
Bitmap image = new Bitmap(Server.MapPath("image.png"));
Graphics g = Graphics.FromImage(image);
Rectangle area = new Rectangle(0,0,image.Width-1, image.Height-1);
Pen pen = new Pen(Color.SkyBlue);
LinearGradientBrush lgBrush = new LinearGradientBrush(area, Color.White, Color.FromArgb(220,220,220), LinearGradientMode.Vertical);
g.FillRectangle(lgBrush, area);
g.DrawRectangle(pen, area);
SolidBrush brush = new SolidBrush(Color.Black);
Random random = new Random();
int randomCharIndex = 0;
char randomChar;
int charPosition = 10;
string captcha = "";
for (int i = 0; i < 7; i++)
{
randomCharIndex = random.Next(0, strString.Length);
randomChar = strString[randomCharIndex];
g.DrawString(Convert.ToString(randomChar), new Font("arial", random.Next(16,25)), brush, charPosition, 10);
charPosition += 17;
captcha += Convert.ToString(randomChar);
}
Session["CAPTCHA_CODE"] = captcha;
Response.ContentType = "image/jpeg";
image.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
}
}
and take a folder name image and paste a i mage now code ready....
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