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ASP.NET version 2.0 includes a wide array of Web controls not found in previous versions. One such control is the TreeView, which is ideal for displaying hierarchical data. The TreeView control can be bound to a hierarchical data source such as the XmlDataSource or SiteMapDataSource, or can be constructed programmatically.

One common source of hierarchical data is the web server's file system. In many scenarios, there may be a folder that contains subfolders and files that the user needs to be able to browse. Using the classes in the System.IO namespace, we can programmatically populate the TreeView with the directory structure of our website. Then, when the user clicks a folder, the selected folder's files can be displayed.

In this article we will examine how to create a simple image gallery web page that's a breeze to maintain. The image gallery lacks the bells and whistles found in more complex and feature-rich image galleries, but this one is a cinch to deploy and maintain. We'll be using two Web controls: a TreeView to list the folders and subfolders in which the images reside; and a DataList control that lists each image in the selected folder..

Many websites display a news ticker of one sort or another. A news ticker is a user interface element that displays a subset of a list of items, cycling through them one at a time after a set interval. For example, on Cisco's website there is a news ticker that shows the company's latest news items. Each news item is a one sentence link, such as "Desktop Virtualization Gathers Steam," or "Cisco Reports First Quarter Earnings." Clicking a headline whisks you to a page that shows the full story. Cisco's news ticker shows one headline at a time; every few seconds the currently displayed headline fades out and the next one appears. In total, Cisco has five different headlines - the ticker displays each of the five and then starts back from the beginning.

This article is the first in a series that explores how to create your own news ticker widget using jQuery and ASP.NET. jQuery is a free, popular, open-source JavaScript library that simplifies many common client-side tasks, like event handling, DOM manipulation, and Ajax. This article kicks off the series and shows how to build a fairly simple news ticker whose contents can be specified statically in HTML markup or created dynamically from server-side code. Future installments will explore adding bells and whistles, such as: stopping the news ticker rotation when the mouse is hovered over it; adding controls to start, stop and pause the headlines; loading new headlines dynamically using Ajax; and packaging the JavaScript used by the ticker into a jQuery plugin.

Read on to learn more!

When creating ASP.NET 2.0 applications, developers commonly store sensitive configuration information in the Web.config file. The cannonical example is database connection strings, but other sensitive information included in the Web.config file can include SMTP server connection information and user credentials, among others. While ASP.NET is configured, by default, to reject all HTTP requests to resources with the .config extension, the sensitive information in Web.config can be compromised if a hacker obtains access to your web server's file system. For example, perhaps you forgot to disallow anonymous FTP access to your website, thereby allowing a hacker to simply FTP in and download your Web.config file. Eep.

Fortunately ASP.NET 2.0 helps mitigate this problem by allowing selective portions of the Web.config file to be encrypted, such as the section, or some custom config section used by your application. Configuration sections can be easily encrypted using code or aspnet_regiis.exe, a command-line program. Once encrypted, the Web.config settings are safe from prying eyes. Furthermore, when retrieving encrypted congifuration settings programmatically in your ASP.NET pages, ASP.NET will automatically decrypt the encrypted sections its reading. In short, once the configuration information in encrypted, you don't need to write any further code or take any further action to use that encrypted data in your application.

In this article we'll see how to programmatically encrypt and decrypt portions of the configuration settings and look at using the aspnet_regiis.exe command-line program. We'll then evaluate the encryption options ASP.NET 2.0 offers. There's also a short discussion on how to encrypt configuration information in ASP.NET version 1.x.

The ASP.NET Web Forms model strives to encapsulate the lower level complexities involved in building a web application. Features like server-side event handlers, the page lifecycle, and view state effectively blur the line between the client and the server, simplify state management, and free the developer from worrying about HTTP, requests and responses, and similar matters. While these facets of the Web Forms model allow for rapid application development and make ASP.NET more accessible to developers with a web application background, their behavior can impact your website's behavior and performance.

View state is perhaps the most important - yet most misunderstood - feature of the Web Forms model. In a nutshell, view state is a technique that automatically persists programmatic changes to the Web controls on a page. By default, this state is serialized into a base-64 encoded string and included as a hidden <input> field in the Web Form. On postback, this state information is returned to the server as part of the POST request, at which point the server can deserialize it and reapply the persisted state to the controls in the control hierarchy. (If this last paragraph made crystal clear sense, great! If not, consider reading my article, Understanding ASP.NET View State, and Dave Reed's article, ViewStateMode in ASP.NET 4, before continuing.)

One potential issue with view state is that it can greatly bloat the size of your web pages. Each new version of ASP.NET seems to include new techniques for managing view state's footprint. ASP.NET 4 adds a new property to all Web controls, ViewStateMode, which allows developers to disable view state for a page by default and then selectively enable it for specific controls. This article reviews existing view state-related properties and then delves into the new ViewStateMode property.