how to generate barcode in asp.net c# Part I CLR Basics in .NET

Integration Denso QR Bar Code in .NET Part I CLR Basics

The brackets on the Session object indicate an indexer . The indexer is a convenient syntax for expressing keys both when inserting data into and retrieving data from the Session object . Do note, however, that if the key you provide doesn t map to a piece of data in the session dictionary, the Session object will return null . In production code, it s always wise to check for a null value and react accordingly . Managing session state in ASP .NET is extraordinarily convenient . In ASP .NET, session state can live in a number of places, including (1) in proc in the ASP .NET worker process, (2) on a separate state server running a Windows Service process, and (3) in a Microsoft SQL Server database . Because session management follows the provider pattern you saw in earlier chapters, you can replace relatively easily the ASP .NET built-in session state management with an implementation of your own . First, start by getting a taste of using session state right now .

service. An entity that uses an interface to provide functionality to other modules in a loosely coupled way. A service is often a singleton. state-based navigation. Navigation accomplished by using state changes to existing controls in the visual tree. UI composition. The act of building an interface by composing it from discrete views at run time, often from separate modules. view. The main unit of UI construction in a composite UI application. The view encapsulates the UI and UI logic that you would like to keep as decoupled as possible from other parts of the application. You can define a view as a user control, data template, or even a custom control. view-based navigation. Navigation accomplished by adding or removing elements from the visual tree. view-first composition. A composition approach in which the view is logically created first, followed by the view model or presenter on which it depends. view discovery. A way to add, show, or remove views in a region by associating the type of a view with a region name. Whenever a region with that name displays, the registered views will be created automatically, and then added to the region. view injection. A way to add, show, or remove views in a region by adding or removing instances of a view to a region. The code interacting with the region does not have direct knowledge of how the region will handle displaying the view. view model. An entity that encapsulates the presentation logic and state for the view. It is responsible for coordinating the view s interaction with any required model classes.

Arrays are collections of objects, and so are hashes. However, hashes have a different storage format and way to define each object within the collection. Rather than having an assigned position in a list, objects within a hash are given a key that points to them. It s more like a dictionary than a list, as there s no guaranteed order, but just simple links between keys and values. Here s a basic hash with two entries: dictionary = { 'cat' => 'feline animal', 'dog' => 'canine animal' } The variable storing the hash is dictionary, and it contains two entries, as you can prove: puts dictionary.size

The SiteMapDataSource control is used to connect to site navigation data for your website. The data for this control is defined in a special XML file called a web.sitemap. You can define one sitemap file in the root of your website. The file includes information about the pages in your site and their hierarchy. It also includes page names, navigational information, and a description of each page. It is meant as a central place for managing the navigational data of your site; it is used by controls such as Menu and TreeView to allow users to easily navigate your application. As an example, suppose that the following web.sitemap file is defined at the root of your web application.

9

The Session_End event is not always raised. When your state mode is set to InProc, ASP.NET will raise the Session_End event when a session is abandoned or times out. However, it does not raise this event for other state modes.

Fabrikam Shipping uses claims for two purposes. It uses role claims to control access and it also uses claims to retrieve user pro le information. Access control to Fabrikam Shipping is based on one of three roles: Shipment Creator. Anyone in this role can create new orders. Shipment Manager. Anyone in this role can create and modify existing shipment orders. Administrator. Anyone in this role can con gure the system. For example, they can set shipping preferences or change the application s appearance and behavior ( look and feel ). The pro le information that Fabrikam Shipping expects as claims is the sender s address and the sender s cost center for billing. The cost center allows Fabrikam to provide more detailed invoices. For example, two employees from Adatum who belong to two different departments would get two different bills. Fabrikam con gures claims mappings for every new customer that uses Fabrikam Shipping. This is necessary because the application logic within Fabrikam Shipping only understands one set of role claims, which includes Shipment Creator, Shipment Manager, and Administrator. By providing these mappings, Fabrikam decouples the application from the many different claim types that customers provide.

Builds the latest version of the source code at the time the build is queued. Builds the latest version of the source code at the time the build starts (default). Builds the version speci ed by the /customGetVersion parameter.

7

Before You Begin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2

Figure 10-12. Final Project in Expression Blend Getting the code perfect is not the point of this exercise. It s OK if your application doesn t look exactly like my screenshot. The main objective was to get you familiar with setting and resetting inline properties in Expression Blend. In these two exercises, you saw how to change the appearance of your Silverlight applications using inline properties in Visual Studio 2008 and Expression Blend. Although this method is very straightforward, in a normal application with a lot of controls, setting all of the properties can become tedious. And if you need to change the appearance of some elements throughout the application, it will not be an easy task. This is where Silverlight styles come in.

You can use similar techniques when you just want to assign a sequence of unique values starting with 1 (and increasing by 1 from there) that is unrelated to any existing sequence. I will describe such techniques later in the chapter in the "Assignment UPDATE" section. So far, I demonstrated inserting a result set into a target table and modifying the rows with new sequence values. Instead, you can use a SELECT INTO statement to populate a temporary table with the target rows, and also to assign row numbers starting with 1 and increasing by 1 from there. (Let's call the column rn.) To generate the row numbers, you can use the IDENTITY function in SQL Server 2000 and the ROW_NUMBER function in SQL Server 2005. Right after the insert, store the @@rowcount value in a local variable (@rc) and invoke the procedure usp_SyncSeq to increment the sequence by @rc and assign the first sequence value in the new block to your variable (@key).