Captcha in ASP.NET - asp.net

I am developing a website where I need a captcha control and I want to develop the captcha control itself, so in the future I can change its length, type, color, and have it be easy to manage as well.
So, suggest me which technology used for to develop the capha control and how.
I am using asp.net platform with vb.net as the language.

You can try reCAPTCHA.

Check out this (free): http://www.codinghorror.com/blog/2004/10/an-aspnet-captcha-server-control.html
Or Telerik has a great Captcha product (not free).

BotDetect CAPTCHA is excellent. I just used it on a big project. http://captcha.biz/

There are lots of existing options you could use (as others have pointed out). But, if you want to roll your own, you might want to consider WPF/Silverlight. There are a lot tools in there to manipulate/transform letters and numbers that you could utilize.
You could apply a random (or several random) transformations to each letter/number of a randomly generated string of letters/numbers.

Related

how complex can an ASP.NET web page be?

I'm building a Bridge game.
The main page, where you play the game, boast some 200 controls, like buttons that represents the 52 cards, 26 others for won / lost tricks, plenty of text fields... You name it, total some 200.
Actually its been already built and runs under Winforms model, but with the unavoidable question of implementing .NET 4.0 onto user's machine that must run Windows, and installing the software.
Hence I'm considering creating an ASP version (no PHP please, since I'm fluent in VB, and ignorant in C, Java, PHP and the likes).
Is that a "real" option or am I dreaming?
Will it run smoothly for users with a 2MB DSL connection?
Oh, by the way, no MVC please, I'm too old for that sort of sh...t :->
Can it be done? Sure.
The problem for you might be that to do it effectivly you will need to use HTML, CSS, Javascript and the like.
What most likely would be a good idea for you here would be to go the route of Silverlight. It will give you a more rich UI experience and will allow you to code in VB entirely.
I don't see using ASP.BET directly as a good option here. To make it look smooth, you would have to use javascript heavily. I thing you would be better off with Flash.
If you prefer to use pure HTML/Javascript/CSS you can create rich Web UI's by modifying the Document's Object Model (DOM). With little knowledge of Javascript and the usage of some library like: scriptaculus, prototype, sarissa, jquery, you can get rich interfaces. You should take a look at some of these libraries mainly scriptaculus because the set of animations it provides. Another javascript library made for game development is gameQuery.
With that many controls on an ASP.NET page your view state will be gigantic. If you plan on only serving up a couple of games at once then it shouldn't be a problem but you have to actually start thinking about bandwidth with that large of a viewstate. You would be better off with a DOM/jQuery type interface which displayed static images for the cards. All interaction can be handled client side and validated with a server side call.
This might be the perfect opportunity to learn javascript :). Remember each language you learn is another tool in your toolbox. The engineer with the most tools usually wins :).

Any Free source code for captcha images for asp.net?

i am creating a registration form for that i want to implement the captcha image.can i get the source code or any reference.Thanking you
Your best bet is to use reCAPTCHA. It's free, widely used, and well documented. And by using it you'll be helping the project along digitizing old books.
They have code samples for asp.net HERE
Take a look at this article (first result of search string asp.net captcha).

Looking for examples of simple web-based form designers

I have a requirement to implement a "simple" web-based form designer that allows "simple" users to create their own web-based forms. I've come across these things in rich clients, such as Outlook and Acrobat, but my requirements are much simpler and must be web-based.
Pretty layout, custom validation, complex fields and types are simply not a factor. Ideally I would like to find something that is neat like this very SO question composer, in which I'm typing right now, plus the ability to drag a text input box or a checkbox right into the text. Output could be as crude as this:
What is your name? [Fred Bloggs]
Do you have an internet? [x]
I'm using asp.net but the backend technology doesn't really matter as I fear this is all javascript! No need to consider old browsers. Any examples links would be helpful, as well as suggestions for existing open or commercial components. Thank you!
Tried Frevvo ?
Here is a pretty neat one based on jquery Ajax Form Builder
Try FormThis. It allows you to create an Online Web Form at no cost. Drag & Drop designer, Unlimited Fields, Submit/Responses, Calculations, Validation, etc. Can output to PDF if required.

Seeking advice on de-bloating asp.net 3.5

I’m new to .net, though I’ve been writing in classic asp for years. I know it’s time to make the change, but I can’t stand how bloated the HTML becomes.
For example, a simple menu using a web.sitemap and adds over 100 lines of JavaScript and HTML. A simple form with server-side validation adds in masses of ugly JavaScript. And a basic table of data using GridView adds in a ViewState that makes my eyes water.
Call me a purest, though I don’t like sending data to the browser unless it’s needed. And I don’t need a form-riddled menu when a simple unordered list of links will suffice.
So, set in my ways, am I destined to forgo the benefits of the Framework entirely by insisting on writing my own, cleaner code for everything? Or am I missing the point?
As a brief aside I’m a big fan of Campaign Monitor, a newsletter distribution company. They’ve written an elegant and comprehensive user-interface in .net without a single ViewState or bizarre .net-mangeled ID reference. Even the Sign Up form on their website (/signup.aspx) is as clean as a whistle. What’s their secret?
I hope I not the only one. Any advice would be greatly appreciated.
Try ASP.NET MVC or one of the other MVC web frameworks for .NET
If your GridView doesn't need it, then turn ViewState off for it.
Also, please edit your question to say what version of .NET you're using. Some of this gets better, and some does not. You might also want to try VS2010 beta 1, and complain about anything it doesn't fix.
Another idea would be to go on treating ASP.NET like it's classic ASP. Do it exactly the way you're used to, but do it with the idea in mind that there's about 10 years of development work that's gone into solving some of the problems of classic ASP. Once you actually hit one of those problems, find out if ASP.NET has solved it, and how.
For instance, I have a hard time believing you enjoy writing FOR loops to generate table rows. If you get tired of that, learn to use a Repeater control, or a DataList control, or even the old DataGrid control. If you turn ViewState off on those, I think you may find the generated HTML to be acceptable, and you'll find it a lot easier to generate tables and other structures that repeat based on repeating data.
You can opt-out of much of that bloat by not using all the out-of-the-box controls that come with it but I prefer the MVC route that activa suggested
Here is my list:
Keep the use of asp controls to minimum
Turn off Viewstate when it's not need
If you don't want the JavaScript associated with Client Side Validation (with ASP.NET Validation) set the EnableClientScript to False
Use asp:literal instead of asp:Label
Yeah it seems to be that everyone is bashing webforms at the minute for the reasons you have outlined above. HTML heavy Controls, ViewState, no control over ClientIDs all seem to cause an issue with people.
However let is be said that you can use asp.net (webforms) and produce some decent applications.
Control of html is yours through httpModules and httpHandlers and some of the issues mentioned above are fixed in asp.net 4.0
I just listened to a great podcast comparing MVC and webforms. Its in the area you are asking about. Also check out this blogpost by a dotNetNuke regarding the good asp.net code and why people should take a breath before converting everything to mvc.
Having said that I've tried Asp.net MVC and it is awesome. I'd probably look at dotNetNukes code to as its a mature asp.net product.
Also, when you do want to use these newfangled server controls, check out the css friendly control adapters. They clean up much of the bloat.
For client IDs the key thing to remember is to let the framework handle them. If you need to get an element on the client side, remember to emit the control's ClientID property into your script.
I've been using a template system and am very happy with it. Basically write an http handler for .html files and put tokens in the html files that regex could find in one sweep and inject any stuff. (google template c# for more info).
I tried some of the supposedly cool new features of ASP.NET for a little while. I also didn't like most of them. I felt constrained to work within the limitations of the common paradigms Microsoft had dreamed, even though I new how easy it would be to produce the HTML and JavaScript myself to do specifically what I wanted to do without having to learn how to jump through the hoops of so many new Microsoft-specific idiosyncrasies.
Anyway, I stopped using the parts of ASP.NET I didn't like on new code I've been writing lately. When I first started using ASP.NET, nothing in the MSDN documentation jumped out at me about how to avoid such complications, so I posted a couple "Hello, World" at http://www.agalltyr.com/rawaspdotnet.html to help spread the heretical word. I couldn't care less if it's the latest cool technology or the recommended technique. It's a reliable and reasonably efficient tool I can use to do my work.
Oh, and I'm not in the mood to learn ASP.NET MVC either. That's just more idiosyncrasies. Give me a language (C#) and a framework (.NET), and I'll design my own abstraction, thank you.

AJAX form editing and design

I want to build into mt ASP.NET application the ability for users to fill up forms, but the forms are not something I can hard-code into my (Enterprise) software.
So I need one screen that lets end users create the forms. Doing it the 2.0 way, I just love what PollDaddy did in their survey editor (great job guys!). How do I replicate that? (don't worry pollDaddy, my app has nothing to do with survey and I am not at all in your domain (-: )
Since you need to login to the site to play with it, I made a 20 sec video of how it looks like. Please see below and tell me how to best replicate this (as simple as using JQuery tip? use an entire open source project? Buy something?)
Requirements are:
support multiple types of elements (like multiple choice, free text, comboBox)
drag and drop
editing of order
click image for video or here
http://frame.revver.com/frame/120x90/1376799.jpg
The AJAX control toolkit is free and would work for some of this items shown in the video. However, JQuery has tons of plugins it is easy to extend and even easier to use. I would suggest starting there and extending it where needed.
Good Luck
You could build it yourself using an AJAX framework like ASP.NET AJAX or even telerik controls. You could use jQuery but ASP.NET AJAX is free and embeds well with ASP.NET pages. You could buy something, but I've yet to encounter packages as such.

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