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A ZIP file is a popular, decades-old file format used for file compression and archiving. Commonly, such files have a .zip extension and are used to reduce the size of one or more files and/or to archive multiple files and folders into a single file. Additionally, the contents of a ZIP file can optionally be encrypted and viewable only by those who know the password. Both Microsoft's Windows and Apple's Mac OS provide built-in operating system support for opening, reading, and creating ZIP files.

In a recent project I needed to create ZIP files from an ASP.NET application on the fly. Specifically, there was a web page that listed of series of data files that were created by an external process. Users visiting this page select a file to download, which then displays a dialog box in their browser, allowing them to open the file or save it to their hard drive. This user interface worked for most of our users, as they were only interested in downloading one or two files at most. However, some of our users needed to download upwards of 20 files. For them, clicking a download link, saving it to their hard drive, and repeating, 20 times, was frustrating and time consuming. To improve this user interface we created the notion of "download profiles," which allow users to associate a name - like "Accounting Files" - with a collection of file types that are available for download. After creating a "download profile," a user could then choose to download all available files that belong to that profile. This would create a ZIP file with the appropriate files and display a dialog box in the user's browser, allowing them to open or save the ZIP. With this enhancement, our power users can now download their 20 files with one mouse click.

This article starts with a look at different ways to create ZIP files in an ASP.NET application, but then focuses on using the free and open-source DotNetZip library.

Enhances your ASP.NET forms with fancy highlighting and combining validation groups.

This articles provides a guideline on how to create a ASP.NET weather control that will show weather using Google Weather API. This control also contains some property that will let user select the location it will show weather.

The Microsoft Chart controls are a series of classes in the System.Web.UI.DataVisualization.Charting namespace that allow web developers to ability to add charts to their ASP.NET applications. The most pertinent charting-related class is the Chart class, which contains information about the chart's appearance, series, charting areas, and so forth. In most of the demos and code samples we've explored thus far, we've used the Chart class as a Web control, adding the <asp:Chart> declarative markup to our ASP.NET page, setting a few properties and, occasionally, writing a few lines of code. When used as a Web control, the Chart class both creates the chart (as an image) and then renders an <img> element that points to the generated chart image.

Using the Chart Web control is a standard practice in a WebForms application, but it is not suggested when building an ASP.NET MVC application. (While it is possible to add Web controls - including the Chat Web control - to the views of an ASP.NET MVC application, it is generally frowned upon.) So, if we can't use the Chart Web control in an ASP.NET MVC application, how do we display a chart? In addition to being used as a Web control, the Chart class can also be used programmatically. It is quite possible to create a new Chart object, set some properties, plot the data points, and then generate the chart image. In fact, we looked at using this technique in an earlier installment, Programmatically Generating Chart Images, in which we saw (among other things) how to generate chart images programmatically and add them as attachments in an email message.

This article explores how to display charts in an ASP.NET MVC application.

The ASP.NET WebForms model aims to simplify web development by blurring the line between the client and the server. In short, WebForms allow the page developer to set aside the fact that the browser and the web server are temporally, physically, and logically disconnected. The page developer can create server-side event handlers that execute in response to a client-side action (like clicking a button). He can make server-side changes to properties of Web controls on the page and need not worry about reinstating those properties on the subsequent postback. One of the essential ingredients for performing this magic is view state.

View state represents the state of an ASP.NET web page that is to be remembered across postbacks. On each page visit, an ASP.NET web page automatically constructs this state information and stores it to a hidden form field on the page named __VIEWSTATE. When the form is submitted, the browser returns this hidden form field to the server; the ASP.NET page then parses the view state information to reconstruct the state from the previous page visit. This entire process happens automatically behind the scenes and is, in part, what makes ASP.NET web development so accessible.

Unfortunately, there is no such thing as a free lunch, and view state is no exception. The presence of view state adds to the size of the page, thereby resulting in larger page sizes that can negatively effect the user experience. What's more, certain controls - such as DropDownLists and GridViews - can significantly add to the heft of a page's view state. It's a good practice for WebForm developers to keep an eye on their pages' view state sizes to ensure an optimal user experience. This article two ways to programmatically determine a page's view state size and to provide a warning should the view state size exceed some specified threshold.

The UpdatePanel is the workhorse of the ASP.NET Ajax library. It is responsible for defining regions of a web page that trigger partial page postbacks (as opposed to full page postbacks). Such partial page postbacks transfer less information between the client and server and have their user interfaces updated seamlessly, thereby leading to a more interactive user experience. (For more information on UpdatePanels, refer to Using the UpdatePanel.) One side-effect of a partial page postback is that the HTML elements within the UpdatePanel are replaced with the markup returned on postback. This behavior is not noticeable and is not an issue unless you have client-side event handlers wired up to the elements within the UpdatePanel. Such client-side event handlers are lost after a partial page postback.

Consider a very simple UpdatePanel that contains just a TextBox and a Button. Furthermore, assume we have JavaScript on the page that creates an event handler for the TextBox's focus and blur events, which "highlights" the TextBox when the user focuses it and unhighlights it when losing focus. Initially, this script works as expected - clicking on the TextBox will "highlight" it. However, things break down once the Button is clicked. When the Button is clicked the UpdatePanel triggers a partial page postback and submits an asynchronous HTTP request back to the server. The requested ASP.NET page then goes through its life-cycle again, but this time only the markup in the UpdatePanel (and the hidden form fields on the page) are returned to the browser. The UpdatePanel then overwrites its existing markup with the markup just returned from the server. Unfortunately, this overwriting obliterates the focus and blur client-side event handlers, meaning that selecting the TextBox no longer highlights it.

In short, if there are client-side event handlers attached to HTML elements within an UpdatePanel it is imperative that they be rebound after a partial page postback. This article looks at three different ways to accomplish this.

Protect against obsolescence, gain new capabilities and increase your marketability by getting on board with the .NET Framework 4. You can start right here by learning how to migrate older applications to the latest and greatest.

Last week's article, Implementing the Store Locator Application Using ASP.NET MVC (Part 1), started a two-part article series that walked through converting my ASP.NET store locator application from WebForms to ASP.NET MVC. Last week's article stepped through the first tasks in porting the store locator application to ASP.NET MVC, including: creating the new project; copying over stylesheets, the database, scripts, and other shared content from the WebForms application; building the HomeController; and coding the Index and StoreLocator actions and views.

Recall that the StoreLocator action and view prompts the user to enter an address for which to find nearby stores. On form submission, the action interfaces with the Google Maps API's geocoding service to determine if the entered address corresponds to known latitude and longitude coordinates. If so, the user is redirected to the StoreLocatorResults action (which we create in this article) that displays the nearby stores in both a grid and as markers on a map. Unlike the StoreLocator action created in Part 1, the StoreLocatorResults action uses a more intricate model and a strongly-typed view.

A self-diagnostics page, that runs through your web.config and confirms all the settings are correct, is a quick and easy way to identify environment problems after configuration change or production deployment.

Your ASP.NET MVC application needs reports. What do you do? In this article, I will demonstrate how simple it is to weave SQL Server Reporting Services (SSRS) into your ASP.NET MVC Applications.Your ASP.NET MVC application needs reports. What do you do? In this article, I will demonstrate how simple it is to weave SQL Server Reporting Services (SSRS) into your ASP.NET MVC Applications.Your ASP.NET MVC application needs reports. What do you do? In this article, I will demonstrate how simple it is to weave SQL Server Reporting Services (SSRS) into your ASP.NET MVC Applications.Your ASP.NET MVC application needs reports. What do you do? In this article, I will demonstrate how simple it is to weave SQL Server Reporting Services (SSRS) into your ASP.NET MVC Applications.