Tutorials & Tips

Session state can be used to identify same visitor between requests. Session variables act as global variables, visible from all .aspx pages on website. This tutorial explains how to write, read and delete ASP.NET session state variables and avoid common problems.

If visitor doesn't make any web request in time interval longer than specified as session timeout (20 minutes by default), session will expire. That means all session variables will be deleted. Sometimes, we want to keep session alive and wait while user is completing some long task. This tutorial explains how to keep ASP.NET Session alive using JavaScript, jQuery, Meta Refresh or ASP.NET Ajax.

ASP.NET web application could restart or stop for numerous reasons. Most of the time, we would like that ASP.NET website is alive. To save resources, web server could restart or completely stop web application many times per day. Every time when this happens, website visitors could experience slow page loads, sessions could be lost, or even see error message in browser like "408 Request Timeout", "500 Internal Server Error", "503 Service Unavailable" etc. This tutorial explains what you can do when ASP.NET application restarts or stops execution.

To preserve web server's resources, session expires after certain time of inactivity (20 minutes by default). If there are no new requests from same visitor, all session data related to that visitor are deleted from server's memory. This could be a problem in some scenarios. This tutorial explains different ways how you can manipulate ASP.NET session state timeout and keep sessions alive.

Very often, there is a need to execute some code on certain date and time, or to repeat execution in regular time intervals. In case of ASP.NET web application, that could be sending of reminder e-mails, analyze traffic data, creating reports, maintenance tasks etc. Unfortunately, ASP.NET doesn't provide some straightforward way to schedule tasks. This tutorial explains how to simulate scheduled task using ASP.NET only, using Timer, Thread or Cache expiration.

If you build any kind of report, very often requirement is to display result of some aggregate function bellow of numeric column. For example, that could be an average sales per customer, summary of time spent on project or similar that acts as some kind of conclusion for certain column and helps user to better understand report. This tutorial explains how to show total or other aggregate functions in GridView footer.

Regex class represents regular expression in .Net RegEx engine, located in System.Text.RegularExpressions namespace. This tutorial explains how to use Regex class in four common regular expressions scenarios: extract data, search-and-replace, split string and data validation.

Regular expressions are powerful way to validate data, especially useful for complex data patterns where other methods like classic string manipulation can't help. Programmers often avoid learning of regular expressions because they look difficult on the first look. This tutorial explains how to validate data that comes from web form, query string, cookies etc. using regular expressions in ASP.NET.

Software Development with C# needs to work with dates and times. To work efficiently with Date and Time .NET has the System.DateTime (DateTime) namespace to help us. You can use DateTime to get DateTime values, generate new DateTime values and format DateTime values (parse strings into DateTime or DateTime in the string format).

Raw data from database sometimes are not suitable for showing on web form directly. For example, you could need additional formatting for date values, show some message instead of NULLs, change 0 and 1 to data more intuitive to your visitors, show warning if value is too high or just change cell styles like background color, font color etc. This tutorial explains different ways to change GridView's styles and data depending of some condition.

GridView, DetailsView or FormView controls are complex controls that have many pre-built features, including data paging or sorting. On opposite, Repeater or DataList offer more control over HTML output and they usually work faster than GridView, but better performances come with lack of these complex GridView's features. This tutorial explains how to use PagedDataSource class to make paging with Repeater or DataList controls.

If you create ASP.NET web application or custom web control that should be distributed to customers worldwide, you need to protect your code from pirates, unlicensed users and competitors. This tutorial explains why and how to use obfuscation and other methods of code protection in ASP.NET.

ASP.NET MVC is new technology that becomes very popular. However, MVC is not replacement for Web Forms. Both will stay with us in longer period and be supported by Microsoft. The next logical question is: Which technology is better? Or at least which is better for my next project? This tutorial introduces short check list to help you decide between MVC and Web Forms for your next ASP.NET project.

One of most important factors for search engine optimization is to have keywords in URL of the page. Dynamically created pages usually have query strings, thus URL looks encrypted and it is not SEO friendly. This tutorial explains several different ways how you can implement URL rewriting in ASP.NET web application to get nice looking URLs while dynamic URL executes in behind.

Gravatar is a popular avatar service that links email addresses to the avatar. You do not need to register an account to be able to display gravatars on your site. All you need to do is construct the URL of the image using the user’s email.

In most of the cases specially for reporting purpose we need to merge GridView cells or columns for client preferred output. In this example i will show you how one can merge GridView cells or columns in asp.net C#. My special focus is on to merge cells when both contains same or equal data. So that the GridView looks like a traditional report. For merging GridView cells here i want to show you a generic way so that you can use only one common method for all GridViews in your project where applicable. Let i have 3 tables named Brand,Category and product. I want to merge all brand & category if consecutive rows contains same data.

ASP.NET MVC is a framework, created by Microsoft, as an alternative (but not replacement) to ASP.NET Web Forms. This tutorial explains what is ASP.NET MVC, why we need it and how to create simple MVC project.

Asp.net GridView gives us huge facility that we can't imagine few years ago. But still we have a lot of chance to improve look & feel as well as GridView functionality. Here in this article i will describe how you can highlight a gridview row when move the mouse over the row and also how to retain the original background color when user leaves the mouse from a row or in mouseout event.

Email is extremely popular way of communication. To make this task easier, Microsoft .Net Framework contains System.Net.Mail namespace. This tutorial explains an options how you can add an image to email in ASP.NET web application.

Master page and content page work together to produce output to client. Sometimes, interaction between master page and content page is needed. This tutorial explains how to access controls, variables, properties, parameters and events from content page to master page and vice versa.