Interview Questions in ASP.NET

Explain the .NET architecture.
How many languages .NET is supporting now? - When .NET was introduced it came with several languages. VB.NET, C#, COBOL and Perl, etc. The site DotNetLanguages.Net says 44 languages are supported.

How is .NET able to support multiple languages? - a language should comply with the Common Language Runtime standard to become a .NET language. In .NET, code is compiled to Microsoft Intermediate Language (MSIL for short). This is called as Managed Code. This Managed code is run in .NET environment. So after compilation to this IL the language is not a barrier. A code can call or use a function written in another language.

How ASP .NET different from ASP? - Scripting is separated from the HTML, Code is compiled as a DLL, these DLLs can be executed on the server.

Resource Files: How to use the resource files, how to know which language to use?

What is smart navigation? - The cursor position is maintained when the page gets refreshed due to the server side validation and the page gets refreshed.

What is view state? - The web is stateless. But in ASP.NET, the state of a page is maintained in the in the page itself automatically. How? The values are encrypted and saved in hidden controls. this is done automatically by the ASP.NET. This can be switched off / on for a single control

Explain the life cycle of an ASP .NET page.

How do you validate the controls in an ASP .NET page? - Using special validation controls that are meant for this. We have Range Validator, Email Validator.

Can the validation be done in the server side? Or this can be done only in the Client side? - Client side is done by default. Server side validation is also possible. We can switch off the client side and server side can be done.

How to manage pagination in a page? - Using pagination option in DataGrid control. We have to set the number of records for a page, then it takes care of pagination by itself.

What is ADO .NET and what is difference between ADO and ADO.NET? - ADO.NET is stateless mechanism. I can treat the ADO.Net as a separate in-memory database where in I can use relationships between the tables and select insert and updates to the database. I can update the actual database as a batch.
The .NET world according to Microsoft
When it comes to Web services, there are essentially two world-views: Microsoft's and everyone else's. Microsoft's world-view, of course, is called .NET and while most people have heard of it, its exact outlines are often fuzzy -- so fuzzy, in fact, that a TechTarget survey found that under 10% of respondents even understand what .NET is. (Click here for more information about the survey.)

To bring .NET into focus, this week I'll start a two-part series about the architecture. This column takes a look at .NET's basic building blocks, while the next one will look at some of the architecture's more controversial aspects, including its Passport technology and new TrustBridge technology.

A look at the basics
For a start, .NET is not a drastic departure from Web services -- it's simply Microsoft's version of the technology. So the roles of UDDI, XML, SOAP, and other basic protocols are essentially no different in the Microsoft view of the world than in the rest of the Web services world.

How those services are used and built, though, differs in .NET from the rest of the world. And there's the rub. In theory, when you build a Web service, you should be able to pick and choose among technologies and vendors, assembling a "best-of-breed" suite of development platforms, servers, security and other tools in order to deliver your service. With .NET that's not really the case: In essence, Microsoft offers a soup-to-nuts approach with .NET, in which every part of the process, and every piece of hardware and software comes from Microsoft and is based on Windows. In fact, cynical observers might believe that Microsoft's head-first jump into Web services via .NET is nothing more than an attempt to shore up Windows in the face of a Web services architecture in which protocols like SOAP, UDDI, and XML could conceivably make an underlying operating system irrelevant.

Whether you believe that, or whether you instead believe that .NET is Microsoft's coherent strategy for making it easier for developers and users to achieve a kind of universal connectivity, you need to know about the core of .NET. So here is the current lineup of what .NET is and how it works, according to Microsoft.

The building blocks of .NET
In the Microsoft vision, there are four primary building blocks of .NET:


1) Developer tools, including Microsoft Visual Studio .NET and the Microsoft .NET Framework;

2) Servers, including .NET Enterprise Servers and the .NET Server Family;

3) XML-based Web services, which are the applications themselves, such as the Microsoft MapPoint .NET, a modular Web service that can be integrated into other applications and Web sites; and

4) Smart clients, which are the devices that run the Web services, and can be anything from a PC to a PocketPC, to the Xbox gaming console. Not surprisingly, they all run some version of Windows.
In the rest of this column, we'll take a closer look at each.

Developer tools The centerpiece of Microsoft's developer tools is Visual Studio .NET, which allows developers to use a variety of languages including Microsoft's Visual Basic .NET, C++ .NET, and Visual C# .NET to build .NET services. Notably missing from the lineup, of course, is Java -- no surprise, since Microsoft has all but abandoned its support for Java. Java developers who do want to develop for .NET can use Visual J# .NET, the beta of which has just been released. (Note: For more information about Visual Studio, head to http://msdn.microsoft.com/vstudio/, and for information about Visual J# .Net, go to http://msdn.microsoft.com/vjsharp/.) Also part of the tools is the .NET Framework, required to build and run Web services. [Editor's Note: For more .NET resources, be sure to also visit the SearchVB .NET Info Center.]

Servers Microsoft has several server product lines that support .NET: Windows 2000 Servers and .NET Enterprise Servers, and the upcoming Windows .NET Server Family. In essence, the Windows 2000 Servers and .NET Enterprise Servers are nothing new, and to a certain extent merely extend existing server software, with an eye toward supporting .NET and XML. Of them, the Microsoft BizTalk Server 2000, which serves XML-based business processes, is particularly relevant, but to one degree or another, most of Microsoft's server line supports NET. The Windows .NET Server family, on the other hand, was designed specifically for .NET and so will greater . NET support. It's currently in beta 3, includes the .NET Framework built into it, and integrates with other .NET technologies such as Microsoft Passport.

XML-based Web services These, of course, are the Web service applications themselves. After an initial flurry of announcements indicating that Microsoft was going full-bore into developing consumer-level .NET services such as stock alerts and similar services, it's now unclear where it plans to go with developing .NET services itself. One of few functioning Web services is the MapPoint .NET service -- a useful if run-of-the-mill service that lets you find maps and driving directions, and that, for a price, can be integrated into a Web site using .NET.

Smart clients In the Microsoft world-view, Windows will run on everything from cell phones to PDAs to gaming consoles, to kiosks -- in fact, anything that has any intelligence built into it. And the plan is that those "smart client" devices will be .NET capable. In the long run, the most interesting of these devices won't be computers -- it may be your refrigerator, toaster or car. Microsoft is pushing Windows XP Embedded, a "componentized" version of the operating system designed to run on any kind of intelligent device. So .NET services could connect all of your home appliances into larger networks of retail stores, automobiles, gaming consoles and more...think of it as .NET everywhere.
What is Microsoft .NET?

Microsoft .NET is the Microsoft strategy for connecting systems, information, and devices through Web services so people can collaborate and communicate more effectively. .NET technology is integrated throughout Microsoft products, providing the capability to quickly build, deploy, manage, and use connected, security-enhanced solutions through the use of Web services.

What are Web Services?

Web services are small, reusable applications that help computers from many different operating system platforms work together by exchanging messages. Web services are based on industry protocols that include XML (Extensible Markup Language), SOAP (Simple Object Access Protocol), and WSDL (Web Services Description Language). These protocols help computers work together across platforms and programming languages.

From a business perspective, Web services are used to reenable information technology so that it can change, move, and adapt like other aspects of a business. They not only connect systems, they can help connect people with the information they need, within the software applications they are used to using, and wherever they happen to be.

Microsoft offers a complete range of software that helps organizations and individuals benefit from Web service-based connectivity. These include theMicrosoft Visual Studio .NET 2003 developer tools, the Windows Server System that hosts Web services, and familiar desktop applications such as the Microsoft Office System that "consume" Web services.



This illustration shows the relationship between the core technology components of .NET.

What are the Benefits of .NET?

.NET technologies use Web services to help enhance the computing experience with highly integrated communications and information. Because .NET includes the core technologies for building Web services, it benefits everyone: individual users, organizations, and developers.
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.NET benefits organizations by helping them get the most out of their existing technology investments while creating new ways to implement powerful, cost-effective information technology that will meet future needs. .NET technologies and Web services can be used to integrate even the most disparate computing environments. .NET frees organizations from the confines of proprietary technology, providing the flexibility and scalability that can help organizations connect their existing IT systems and build a foundation for the next wave of computer technology. .NET and Web services can help organizations lower operating costs by helping connect systems; increase sales by helping employees access the right information when and where they need it; integrate services and applications with customers and partners; and lower the costs of information technology with tools that help developers quickly create new solutions to address business issues.
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.NET benefits individuals by helping provide a more personal and integrated computing experience. .NET-enabled computing is centered on the user–not on the features of the software or hardware. The user's experience becomes very customizable and provides integrated data and customized interactions that work well with a wide range of computing hardware, such as Pocket PCs, Smartphones, laptops, and other devices. The .NET-based experience enhances the mobile computing experience so user's can get their information regardless of their location. For example, it can take place on a desktop computer, in the car on a Smartphone, or at the store on a Pocket PC.
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.NET benefits developers by providing a tightly integrated set of tools for building and integrating Web services. Visual Studio .NET and the .NET Framework provide comprehensive development platforms that offer the best, fastest, and most cost-effective way to build Web services. With Visual Studio .NET and the .NET Framework, developers can take advantage of a programming model designed from the ground up for creating Web services in a highly productive, multilanguage environment. With scalable, high-performance execution, the .NET tools allow developers to use existing skills to create a wide range of solutions that work across a broad array of computing devices. .NET also provides a foundation for building Service Oriented Architectures (SOA).

What are Service Oriented Architectures (SOA)?

SOA describes an information technology architecture that enables distributed computing environments with many different types of computing platforms and applications. Web services are one of the technologies that help make SOAs possible. As a concept, SOA has been around since the 1980s, but many early IT technologies failed to achieve the goal of linking different types of applications and systems. By making early investments with .NET, Microsoft has helped provide the building blocks that today are putting many enterprise customers on the path to successfully implementing SOAs. With SOAs, companies can benefit from the unimpeded flow of information that is the hallmark of connected systems.

What are Web Services Enhancements for Microsoft .NET (WSE)?

WSE is an add-on to Microsoft Visual Studio .NET and the Microsoft .NET Framework that helps developers build greater security features into Web services using the latest Web services protocol specifications and standards. With WSE 2.0 developers can create security-enhanced connected systems that help improve business processes within–and beyond–corporate trust boundaries and create new revenue-generating opportunities.

What is a Smart Client?

Smart clients are client applications that consume Web services and reside on user hardware such as desktop PCs, laptops, Pocket PCs, and Smartphones. They are easily deployed and managed and provide an adaptive, responsive, and rich interactive experience by taking advantage of the computing resources on the device and intelligently connecting to distributed data sources.

What is .NET Passport?

.NET Passport is a Web-based service that is designed to make signing in to Web sites fast and easy. Passport enables participating sites to authenticate a user with a single set of sign-in credentials, alleviating the need for users to remember numerous passwords and user names.

What are the Current Microsoft Products and Technologies That Use .NET?

Microsoft .NET provides everything that is needed to develop and deploy a Web service-based IT architecture: servers to host Web services; development tools to create Web services; applications to use them; and a network of more than 35,000 Microsoft partners to help organizations deploy and manage them. .NET technologies are supported throughout the family of Microsoft products, including the Windows Server System, the Windows XP desktop operating system, and the Microsoft Office System. And .NET technologies will play an even larger role in future versions of Microsoft products.

Who is Using .NET?

Organizations worldwide are implementing .NET technologies and Web services to create connected businesses and to help individuals communicate and collaborate more effectively. For example, Honeywell, GlaxoSmithKline, Sony, Dollar Rent A Car, Farmers Insurance, and the United States Postal Service are just a few of the well-known names that are using .NET. To read more about .NET technology in use today, visit the Microsoft .NET Case Study site.

How Do I Find a Microsoft Partner to Help Me Connect My Organization Using .NET?

Microsoft Certified Partners are independent companies that can provide you with the highest levels of technical expertise, strategic thinking, and hands-on skills. Microsoft Certified Partners encompass a broad range of expertise and vendor affiliations. Their real-world perspective can help you prioritize and effectively deliver your technology solutions. Find a partner in your area, here.
ASP.NET is a technology for building powerful, dynamic Web applications. It is part of the .NET Framework.

Developer Productivity

ASP.NET helps you deliver real world Web applications in record time.

Easy Programming Model ASP.NET makes building real world Web applications dramatically easier. ASP.NET server controls enable an HTML-like style of declarative programming that lets you build great pages with far less code than with classic ASP or technologies like PHP or JSP. Best of all, ASP.NET pages work in all browsers – including Firefox, Opera, Safari, and Internet Explorer.

Great Tool Support A broad range of tools support development with ASP.NET. You can work with a simple text editor (even Notepad), take advantage of the freely available Visual Web Developer 2005 Express Edition, or work with a full-powered integrated development environment, such as Visual Studio 2005. For enterprise developers, Visual Studio Team System 2005 includes additional tools for stress-testing and designing Web applications.

Starter Kits Not sure how to get started building an ASP.NET Web site? Download one of the ASP.NET Starter Kits – ready-built Web sites using best practices to help you see how a site should be created. Starter Kits for personal, club, portal and e-commerce Web sites are already available, and both Microsoft and third parties are making many more available.

Easy to get started Quickly get up to speed programming with ASP.NET by following along with the QuickStart tutorials. Read a guided tour of Visual Web Developer to become familiar with its features. Access the broad and growing community support for ASP.NET.


Improved Design

ASP.NET helps you create appealing, functional Web applications.

Master Pages ASP.NET makes it easy to create and apply a common look-and-feel to your Web site with Master Pages. Change the Master Page, and all pages automatically update to reflect those changes.

Themes Give your Web pages a consistent appearance with the built-in theming support in ASP.NET. Easily organize and apply changes to stylesheets and controls by applying a new theme to your pages.


Built Upon Standards

ASP.NET helps you create pages compliant with international standards.

XHTML Compliance Creating XHTML-compliant pages is easy with ASP.NET. Web controls support rendering valid, well-formed XHTML markup with a simple configuration option.

Accessibility Support Create Web applications usable by the widest possible audience support for building and testing accessible Web applications.
Improved Security

ASP.NET helps you protect your data and users.

Application Services There is no need to write common code for managing users and personalization with ASP.NET, as these features are included as application services. ASP.NET membership services provide best practices guidance and support for managing access to your Web applications.

Built-in Protection ASP.NET provides built-in protection from many common forms of hacker attacks, including cross-site scripting, request-replay attacks and more.

Improved Performance and Scalability

ASP.NET lets you use serve more users with the same hardware.

Caching Caching can dramatically improve the performance of Web applications, and ASP.NET supports many forms of caching. Output caching improves the rendering of controls to XHTML. Database caching enables the application to be notified when the underlying database changes, eliminating unnecessary queries.

Web-Farm Session State ASP.NET session state lets you share session data user-specific state values across all machines in your Web farm. Now a user can hit different servers in the web farm over multiple requests and still have full access to her session.


Extensible Architecture

ASP.NET can grow and change with your needs.

Provider Model The application services of ASP.NET use the provider model to connect to external services for storage and more. This enables the developer to change the database or other service used to store the membership, personalization or site map information by editing the configuration.

Web Parts Easily build portal applications with the built-in Web part functionality. Create Web applications that enable end users to organize and personalize their page content and layout.