How to generate own captcha without DLL in asp.net c#
In this article, we are doing the create dynamically
own captcha without any DLL. In this market we have so many 3rd party
tools for making the captcha but on that we do have any right to design that
and making own style.
In this post, we have created a
captchagenerator.aspx page for designing of captcha and reusability of code ,
he can create a this page and we can use as our requirement
Source Code:-
<%@
Page Language="C#" AutoEventWireup="true" CodeFile="captchagenerator.aspx.cs" Inherits="captchagenerator"
%>
<!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></title>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
</form>
</body>
</html>
Code behind(c#):-
using System;
using
System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using
System.Web.UI.WebControls;
using System.Drawing;
using
System.Drawing.Imaging;
using
System.Drawing.Drawing2D;
public partial class captchagenerator : System.Web.UI.Page
{
protected void Page_Load(object
sender, EventArgs e)
{
Response.Clear();
int
height = 30;
int
width = 100;
Bitmap
bmp = new Bitmap(width,
height);
RectangleF
rectf = new RectangleF(10,
5, 0, 0);
Graphics
grph = Graphics.FromImage(bmp);
grph.Clear(Color.White);
grph.SmoothingMode = SmoothingMode.AntiAlias;
grph.InterpolationMode = InterpolationMode.HighQualityBicubic;
grph.PixelOffsetMode = PixelOffsetMode.HighQuality;
grph.DrawString(Session["captchabox"].ToString(), new Font("Thaoma", 12, FontStyle.Italic),
Brushes.Red, rectf);
grph.DrawRectangle(new Pen(Color.Blue), 1, 1, width - 2, height - 2);
grph.Flush();
Response.ContentType = "image/jpeg";
bmp.Save(Response.OutputStream, ImageFormat.Jpeg);
grph.Dispose();
bmp.Dispose();
}
}
Source code :-
<%@
Page Language="C#" AutoEventWireup="true" CodeFile="empregistration.aspx.cs" Inherits="empregistration"
%>
<!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></title>
</head>
<body>
<form id="form1" runat="server">
<div
align="center">
<fieldset style ="width:200px;">
<legend>Registration</legend>
<asp:TextBox ID="txtname" placeholder="Name" runat="server"
Width="180px"></asp:TextBox>
<br />
<br />
<asp:TextBox ID="txtgender" placeholder="Gender" runat="server"
Width="180px" ></asp:TextBox>
<br />
<br />
<asp:TextBox ID="txtlocation" placeholder="Current Location" runat="server"
Width="180px" ></asp:TextBox>
<br />
<br />
<asp:TextBox ID="txtcaptcha" placeholder="Enter Below Captcha" runat="server"
Width="180px" ></asp:TextBox>
<br />
<br />
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Image ID="imgCaptcha"
runat="server"
align="absmiddle"
/>
<asp:Button ID="btnRefresh" runat="server" Text="Refresh"
onclick="btnRefresh_Click"
/>
</ContentTemplate>
</asp:UpdatePanel>
<br />
<br />
<asp:Button ID="btnsubmit" runat="server" Text="Submit"
Width="81px" onclick="btnsubmit_Click" />
<br />
</form>
</body>
</html>
Code behind(c#):-
using System;
using
System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using
System.Web.UI.WebControls;
using System.Text;
public partial class empregistration : System.Web.UI.Page
{
protected void Page_Load(object
sender, EventArgs e)
{
if
(!IsPostBack)
{
bindcaptcha();
}
}
protected void bindcaptcha()
{
Random
random = new Random();
string
combination = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
StringBuilder
captcha = new StringBuilder();
for
(int i = 0; i < 7; i++)
captcha.Append(combination[random.Next(combination.Length)]);
Session["captchabox"]
= captcha.ToString();
imgCaptcha.ImageUrl = "captchagenerator.aspx?" + DateTime.Now.Ticks.ToString();
}
protected void btnsubmit_Click(object
sender, EventArgs e)
{
if
(Session["captchabox"].ToString()
!= txtcaptcha.Text)
{
Response.Write("<script>alert('Invalid
Captcha...')</script");
}
else
{
Response.Write("<script>alert('Valid
Captcha...')</script");
}
bindcaptcha();
}
protected void btnRefresh_Click(object
sender, EventArgs e)
{
bindcaptcha();
}
}
Out-Put:-
For More:-
Export Gridview to Excel Sheet in .Net C# ,How to show on time in the gridview in asp.net C# ,How to bind xml with grid view in asp.net c# ,
How to generate own captcha without DLL in asp.net c#
Reviewed by NEERAJ SRIVASTAVA
on
2:27:00 PM
Rating:
Reviewed by NEERAJ SRIVASTAVA
on
2:27:00 PM
Rating:
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