Saturday, September 26, 2015

Captcha control in

Suggested Videos
Part 163 - Dynamically adding treenodes to treeview control
Part 164 - Displaying organization employee chart using treeview control
Part 165 - How to display an icon for website on browser tab

In this video, we will discuss using captcha control in web application.

What is the use of Captcha control 
The term CAPTCHA stands for Completely Automated Public Turing Test To Tell Computers and Humans Apart. The following are the 2 most compelling reason for using captcha control 

1. To prevent automated computer programs from submitting comments (SPAM). CAPTCHA control ensures only humans can enter comments.

2. To prevent bogus user registrations. For example, when you try to create a new gmail account, notice that there is a captcha control displayed on the registration page. This ensures only humans can register and not automated scripts.

It is very difficult for automated computer programs to read the distorted text displayed in a captcha control.

Example : The data entered in the webform below should only be saved to the database table when captcha control passes validation
captcha in

There are several free captcha controls available on the internet. I have tested reCAPTCHA control with ASP.NET and works very well. It is very easy to integrate as well. Here are the steps.

Step 1 : Sign up for API keys.

Step 2 : Download reCAPTCHA ASP.NET library

Step 3 : Extract Recaptcha.dll from the downloaded ZIP folder

Step 4 : Create an empty web application. Name it Demo. Add a reference to Recaptcha.dll assembly.

Step 5 : Include the database connection string in web.config file

Step 6 : Create database table RegisteredUsers to store data
Create table RegisteredUsers

If you are searching life partner. your searching end with now offer free matrimonial website which offer free message, free chat, free view contact information. so register here : Free matrimonial website