how to create a captcha image in asp.net c# using System.Drawing?

Refer these links
http://www.codeproject.com/Articles/99148/Simple-CAPTCHA-Create-your-own-in-C
http://developerdesk.blogspot.in/2012/11/to-generate-captcha-image-c.html#!/2012/11/to-generate-captcha-image-c.html
http://www.codeproject.com/Articles/169371/Captcha-Image-using-C-in-ASP-NET

For alphanumeric CAPTCHA
http://forums.asp.net/t/1871186.aspx

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Chandu
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--Sample code
//Captcha.ashx.cs

using System;

using System.Web;

using System.Drawing;

using System.IO;

using System.Web.SessionState;

using System.Drawing.Imaging;

using System.Drawing.Text;

using System.Drawing.Drawing2D;



namespace CAPTCHADrawing

{

    /// <summary>

    /// Summary description for Captcha

    /// </summary>

    public class Captcha : IHttpHandler, IReadOnlySessionState

    {

        public void ProcessRequest(HttpContext context)

        {

            int iHeight = 80;

            int iWidth = 190;

            Random oRandom = new Random();



            int[] aBackgroundNoiseColor = new int[] { 150, 150, 150 };

            int[] aTextColor = new int[] { 0, 0, 0 };

            int[] aFontEmSizes = new int[] { 15, 20, 25, 30, 35 };



            string[] aFontNames = new string[] { "Comic Sans MS", "Arial", "Times New Roman", "Georgia", "Verdana", "Geneva"};

            FontStyle[] aFontStyles = new FontStyle[] {   FontStyle.Bold, FontStyle.Italic, FontStyle.Regular, FontStyle.Strikeout, FontStyle.Underline};

            HatchStyle[] aHatchStyles = new HatchStyle[]

                        {

                            HatchStyle.BackwardDiagonal, HatchStyle.Cross, 

	                        HatchStyle.DashedDownwardDiagonal, HatchStyle.DashedHorizontal,

                            HatchStyle.DashedUpwardDiagonal, HatchStyle.DashedVertical, 

	                        HatchStyle.DiagonalBrick, HatchStyle.DiagonalCross,

                            HatchStyle.Divot, HatchStyle.DottedDiamond, HatchStyle.DottedGrid, 

	                        HatchStyle.ForwardDiagonal, HatchStyle.Horizontal,

                            HatchStyle.HorizontalBrick, HatchStyle.LargeCheckerBoard, 

	                        HatchStyle.LargeConfetti, HatchStyle.LargeGrid,

                            HatchStyle.LightDownwardDiagonal, HatchStyle.LightHorizontal, 

	                        HatchStyle.LightUpwardDiagonal, HatchStyle.LightVertical,

                            HatchStyle.Max, HatchStyle.Min, HatchStyle.NarrowHorizontal, 

	                        HatchStyle.NarrowVertical, HatchStyle.OutlinedDiamond,

                            HatchStyle.Plaid, HatchStyle.Shingle, HatchStyle.SmallCheckerBoard, 

	                        HatchStyle.SmallConfetti, HatchStyle.SmallGrid,

                            HatchStyle.SolidDiamond, HatchStyle.Sphere, HatchStyle.Trellis, 

	                        HatchStyle.Vertical, HatchStyle.Wave, HatchStyle.Weave,

                            HatchStyle.WideDownwardDiagonal, HatchStyle.WideUpwardDiagonal, HatchStyle.ZigZag

                        };



            //Get Captcha in Session

            string sCaptchaText = context.Session["Captcha"].ToString();



            //Creates an output Bitmap

            Bitmap oOutputBitmap = new Bitmap(iWidth, iHeight, PixelFormat.Format24bppRgb);

            Graphics oGraphics = Graphics.FromImage(oOutputBitmap);

            oGraphics.TextRenderingHint = TextRenderingHint.AntiAlias;



            //Create a Drawing area

            RectangleF oRectangleF = new RectangleF(0, 0, iWidth, iHeight);

            Brush oBrush = default(Brush);



            //Draw background (Lighter colors RGB 100 to 255)

            oBrush = new HatchBrush(aHatchStyles[oRandom.Next

                (aHatchStyles.Length - 1)], Color.FromArgb((oRandom.Next(100, 255)),

                (oRandom.Next(100, 255)), (oRandom.Next(100, 255))), Color.White);

            oGraphics.FillRectangle(oBrush, oRectangleF);



            System.Drawing.Drawing2D.Matrix oMatrix = new System.Drawing.Drawing2D.Matrix();

            int i = 0;

            for (i = 0; i <= sCaptchaText.Length - 1; i++)

            {

                oMatrix.Reset();

                int iChars = sCaptchaText.Length;

                int x = iWidth / (iChars + 1) * i;

                int y = iHeight / 2;



                //Rotate text Random

                oMatrix.RotateAt(oRandom.Next(-40, 40), new PointF(x, y));

                oGraphics.Transform = oMatrix;



                //Draw the letters with Random Font Type, Size and Color

                oGraphics.DrawString

                (

                    //Text

                sCaptchaText.Substring(i, 1),

                    //Random Font Name and Style

                new Font(aFontNames[oRandom.Next(aFontNames.Length - 1)],

                   aFontEmSizes[oRandom.Next(aFontEmSizes.Length - 1)],

                   aFontStyles[oRandom.Next(aFontStyles.Length - 1)]),

                    //Random Color (Darker colors RGB 0 to 100)

                new SolidBrush(Color.FromArgb(oRandom.Next(0, 100),

                   oRandom.Next(0, 100), oRandom.Next(0, 100))),

                x,

                oRandom.Next(10, 40)

                );

                oGraphics.ResetTransform();

            }



            MemoryStream oMemoryStream = new MemoryStream();

            oOutputBitmap.Save(oMemoryStream, System.Drawing.Imaging.ImageFormat.Png);

            byte[] oBytes = oMemoryStream.GetBuffer();



            oOutputBitmap.Dispose();

            oMemoryStream.Close();



            context.Response.BinaryWrite(oBytes);

            context.Response.End();

        }

        public bool IsReusable

        {

            get

            {

                return false;

            }

        }

    }

}

//CaptchaImage.aspx design

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="CaptchaImage.aspx.cs" Inherits="CAPTCHADrawing.CaptchaImage" %>



<!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>

        <asp:Image ID="imgCaptcha" ImageUrl="Captcha.ashx" runat="server" />

        <asp:TextBox runat="server" ID="txtCaptcha"/>  

        <asp:Button Text="Submit" runat="server" onclick="Unnamed1_Click" />

    </div>

    </form>

</body>

</html>

//CaptchaImage.aspx.cs

u

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--

Chandu

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http://www.c-sharpcorner.com/uploadfile/satyapriyanayak/fghdfghdh/

If this post helps you mark it as answer
Thanks

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Please go through the link...

http://dotnetlearners.com/blogs/view/6/Create-your-own-captcha-image-generator-in-aspnet-using-c-net.aspx
http://dotnetlearners.com/blogs/view/6/Create-your-own-captcha-image-generator-in-aspnet-using-c-net.aspx

http://www.dotnetlearners.com/tutorial/angularjs/17/angularjs-tutorial-introuduction-to-angularjs

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Please go through the link

http://www.aspdotnet-suresh.com/2013/09/create-captcha-with-refresh-button-in-aspnet.html

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hi.. please try this.

protected void Page_Load(object sender, System.EventArgs e)
{
//create object of Bitmap Class and set its width and height.
Bitmap objBMP = new Bitmap(180, 51);
//Create Graphics object and assign bitmap object to graphics' object.
Graphics objGraphics = Graphics.FromImage(objBMP);
objGraphics.Clear(Color.White);
objGraphics.TextRenderingHint = TextRenderingHint.AntiAlias;
Font objFont = new Font("arial", 30, FontStyle.Bold);
//genetating random 6 digit random number
string randomStr = GeneratePassword();
//set this random number in session
Session.Add("randomStr", randomStr);
Session.Add("randomStrCountry", randomStr);
objGraphics.DrawString(randomStr, objFont, Brushes.Black, 2, 2);
Response.ContentType = "image/GIF";
objBMP.Save(Response.OutputStream, ImageFormat.Gif);
objFont.Dispose();
objGraphics.Dispose();
objBMP.Dispose();
}

I hope, it helps..

SAMIR
Sr. Software Engineer

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please refer this article

http://forums.asp.net/t/1935123.aspx

SAMIR
Sr. Software Engineer

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Though I don't have much experience towards this kind of things, I believe this will offer you hints:

http://www.businessrefinery.com/products/barcode_net/net_barcode_generator.html

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Though I don't have much experience towards this kind of things, I believe this will offer you hints: http://www.businessrefinery.com/products/barcode_net/net_barcode_generator.html

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What is the best, most effective and yet easiest way of making image captcha security questions with ASP.net Netframework 4.0 ?
http://www.keepautomation.com/how_to/aspnet/csharp_barcode.html

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