I am using a great Asp.Net CAPTCHA by in a number of web sites with and without Asp.Net AJAX. It’s a simple and really easy to use Asp.Net CAPTCHA. The actual source code is in C#, but you can use it with both C# and VB.Net by simply wrapping the functionality in a class library.In Asp.Net forums and in many other user communities I have seen lot of people asking for VB.Net CAPTCHA. So I thought to write a blog post and create some sample implementations. The zip file contains C# CAPTCHA and VB.Net CAPTCHA. I have included the samples for Asp.Net AJAX CAPTCHA also.Implementing Asp.Net AJAX CAPTCHA is really simple. Just wrap the main Asp.Net CAPTCHA with Asp.Net AJAX update panel and put a random query string at the end of CAPTCHA image src.
The random query string will avoid showing the old CAPTCHA from browser cache.STEPS TO ADD ASP.NET CAPTCHA IN YOUR WEBSITE. Refer the assembly CaptchaDLL.dll in your project. Copy JpegImageCS.aspx or JpegImageVB.aspx (according to the language of choice) to your website. Open the above file and make changes in Colors and Font if needed.
(read the inline comments to know more). Now user the sample codes from Default.aspx or Ajax.aspx pages. The code is straight forward. You make a session and generate an image with the string in the Session. Now when you submit you have to check the session value and textbox value to see whether the entered CAPTCHA is correct.If you have any questions please put as a comment.TagsAsp.Net CAPTCHA, CAPTCHA, VB.Net CAPTCHA, C# CAPTCHA, ASP CAPTCHA, C sharp captcha, vb captcha, simple captcha, AJAX CAPTCHA, asp.net ajax captcha, captcha without refresh, captcha using ajax, numeric captcha. Said.Thanks for the reply. I found that about an hour ago online.Now the problem is that the Captcha image is not appearing.
I have this in a login control. Funny thing is that if I replace the src='JpegImageVB.aspx' with a graphic from my Images folder, the image doesn't display either.The JpegImageVB.aspx file is in the sites root directory.
![Asp.net c ajax captcha code Asp.net c ajax captcha code](/uploads/1/2/5/4/125429839/145065670.png)
When I start with debugging and have a breakpoint in the JpegImageVB.aspx file it doesn't appear the file is being executed.When the login comes up, the alt text 'Visual Verification' appears.Any ideas?
Here Mudassar Ahmed Khan has explained how to implement Captcha Image with Refresh Button in ASP.Net. I had already explained in past “How to use Mondor’s MSCaptcha in ASP.Net”. In this article, I am extending it by adding a Refresh Button to refresh the Captcha image and use of CustomValidator for validating the Captcha against the entered Text. KT.UI for ASP.NET AJAX owns high capability of offering users the comprehensive and simple to use captcha interface controls as well as the corresponding online tutorials for these components. The major properties, controls and online components tutorials are listed here for helping users understand our products quickly.
Today, I am going to show you how to add CAPTCHA with your ASP.NET application. Firstly, create an ASP.NET application.Open Visual Studio 2015, File Menu, New, then Project. It will open a new project window where you can choose the type of the application. So, you need to choose only ASP.NET Web Application. Specify the project name and click OK.From the next screen of the window, you can choose the Web Forms and choose OK.It will create a basic Web Form application for you.
See the following screenshot for your demo application.Add a new ASP.NET web form page “ Register.aspx”. To add a new page, Right Click on the project and choose Add, then New Item.From the New Item, choose Web, then Web Form with Master Page and provide the specific name for the page and click OK.Select your master page for the page and click OK button.To create captcha, I am using other ASP.NET page where I will create captcha image and use it with Register.aspx page.So, add new page “ Captcha.aspx” and make the code for this page as in the following.Captcha.aspx.cs.