.NET news » Examples

Principles of Design Patterns to answer why they exist, who should actually use them and their learning roadmap for beginners (using C#)

The .NET Framework provides a variety of classes in the System.IO namespace that simplify working with the file system. Using these classes it's possible to delete files and folders, to create new files, to edit existing files, and more. These classes, combined with ASP.NET's suite of Web controls and databinding syntax, make it quite easy to present information about the files on the web server's file system to visitors to your website. With a bit of markup and code, it's possible to add a simple file browser to a web page that allows users to view the files and folders from a particular directory on the web server. Such file browsers are useful if you let users upload content to the website and need to let them view their uploaded content. If you have a folder that contains user-accessible content like images, PDF files and Word documents, a file browser offers a quick and easy way for users to see what content is available and to view content of interest.

Back in 2003 I wrote an article titled Displaying the Files in a Directory using a DataGrid that showed how to list the files of a particular folder in a DataGrid Web control. This dated article still attracts a decent amount of traffic and questions from readers, so much so that I thought it worthwhile to update the content to use the latest technology, namely ASP.NET 4 and the GridView Web control. I also added some new features. For example, the file browser now lists both files and folders, allowing users to view the files in subfolders. Also, I moved the markup and code into a User Control, which simplifies adding the file browser to an ASP.NET page. This article walks through this new, updated version; the complete, working code is available for download at the end of this article.

An example using MEF to dynamically load Silverlight Video Players

In the last Baker’s Dozen article, I demonstrated 13 SSIS packages to show what Integration Services can do. This article picks up where the last one left off. I’ll show some capabilities in SSIS, such as handling irregular input files, extracting database changes, implementing package configurations, and leveraging the advanced lookup features in SSIS 2008.

With the help of an example in this article, I have tried to explain a practical multi-threading application design. The Microsoft CLR Profiler tool has been used to get an insight on what is going on. Emphasis is given to development of a generic module as it maximizes code reuse.

Understanding of Example Based Machine Translation (EBMT) system and how to create your own using exisiting tools

One of the new controls available with ASP.NET 4 is the QueryExtender control. The QueryExtender is designed to simplify filtering data returned from a LinqDataSource or EntityDataSource by decoupling the filtering logic from the data source control. Using the QueryExtender is easy - simply add a QueryExtender to the page, specify what data source control it applies to, and then define the filtering criteria. For example, when displaying product information on a web page you could use the QueryExtender control and a few lines of markup to display only those products that are not within a certain price range and whose name or category starts with a user-specified search string.

Filtering the data returned by a LinqDataSource or EntityDataSource control is certainly possible without the QueryExtender; both the LinqDataSource and EntityDataSource controls have a Where property that can be used to specify filtering criteria. What the QueryExtender offers is a simpler means by which to filter data. This article includes a number of demos (which can be downloaded at the end of this article) that showcase the QueryExtender's ease of use and its powerful filtering capabilities.

This article presents commonly used programming fonts with examples of each font in ClearType and non-ClearType.

An enumeration is a special type in the .NET Framework that is comprised of a number of named constants. While you might not have created an enumeration type yourself, you have likely used enumerations many times in day-to-day programming. For example, the rows in a GridView have a RowType property that returns an enumeration of type DataControlRowType that indicates the row's type: Header, Footer, DataRow, and so on.

When working with an enumeration we may need to display a descriptive message based on the enumeration's value. For example, using ASP.NET's Membership system you can programmatically create a new user account calling the Membership class's CreateUser method. This method specifies the success or failure of the operation via the MembershipCreateStatus enumeration. This enumeration has members like Success, InvalidUserName, InvalidPassword, DuplicateUserName, and the like. When calling this method from an ASP.NET page you might want to show the user a descriptive message based on this enumeration value.

This article explores three different ways to provide descriptive text for enumeration members.

Learning Object Oriented Design Patterns through some interesting conversations