Friday, May 29, 2009

How to read xml file in

This Article will see how we can read and XML file it our ASP.NET application using, this trick is use full for making custom configuration files for your application or just reading data stored in an xml file.

Here is an XML save as name "countries.xml":

-------Create xml file follow image below----------------------------

-------End of xml File-----------------------------------------------------------

---------Code Snap-shot-------------

Out Put: Radiobuttonlist will generate like displayed below :




New Features in ASP.NET 3.5


With ASP.NET AJAX, developers can quickly create pages with sophisticated, responsive user interfaces and more efficient client-server communication by simply adding a few server controls to their pages. Previously an extension to the ASP.NET runtime, ASP.NET AJAX is now built into the platform and makes the complicated task of building cross-platform, standards based AJAX applications easy.

New ListView and DataPager Controls

The new ListView control gives you unprecedented flexibility in how you display your data, by allowing you to have complete control over the HTML markup generated. ListView‘s template approach to representing data is designed to easily work with CSS styles, which comes in handy with the new Visual Studio 2008 designer view. In addition, you can use the DataPager control to handle all the work of allowing your users to page through large numbers of records.

LINQ and other .NET Framework 3.5 Improvements

With the addition of Language Integrated Query (LINQ) in .NET Framework 3.5, the process of building SQL queries using error-prone string manipulation is a thing of the past. LINQ makes your relational data queries a first-class language construct in C# and Visual Basic, complete with compiler and Intellisense support. For Web applications, the ASP.NET LinqDataSource control allows you to easily use LINQ to filter, order and group data that can then be bound to any of the data visualization controls like the ListView and GridView controls. In addition, all the other improvements to .NET Framework 3.5, including the new HashSet collection, DateTime offset support, diagnostics, garbage collection, better thread lock support, and more, are all available to you in your ASP.NET applications.

WCF Support for RSS, JSON, POX and Partial Trust

With .NET Framework 3.5, Windows Communication Foundation (WCF) now supports building Web services that can be exposed using any number of the Internet standard protocols, such as SOAP, RSS, JSON, POX and more. Whether you are building an AJAX application that uses JSON, providing syndication of your data via RSS, or building a standard SOAP Web service, WCF makes it easy to create your endpoints, and now, with .NET Framework 3.5, supports building Web services in partial-trust situations like a typical shared-hosting environment.

New Web Features in Visual Studio 2008

New Web Design Interface

Visual Studio 2008 has incorporated a new Web designer that uses the design engine from Expression Web. Moving between design and source view is faster than ever and the new split view capability means you can edit the HTML source and simultaneously see the results on the page. Support for style sheets in separate files has been added as well as a CSS properties pane which clarifies the sometimes-complex hierarchy of cascading styles, so that it is easy to understand why an element looks the way it does. In addition Visual Studio 2008 has full WYSIWYG support for building and using ASP.NET Nested Master Pages which greatly improves the ability to build a Web site with a consistent look and feel.

JavaScript Debugging and Intellisense

In Visual Studio 2008, client-side JavaScript has now become a first-class citizen in regards to its debugging and Intellisense support. Not only does the Intellisense give standard JavaScript keyword support, but it will automatically infer variable types and provide method, property and event support from any number of included script files. Similarly, the JavaScript debugging support now allows for the deep Watch and Locals support in JavaScript that you are accustomed to having in other languages in Visual Studio. And despite the dynamic nature of a lot of JavaScript, you will always be able to visualize and step into the JavaScript code, no matter where it is generated from. This is especially convenient when building ASP.NET AJAX applications.

Multi-targeting Support

In previous versions of Visual Studio, you could only build projects that targeted a single version of the .NET Framework. With Visual Studio 2008, we have introduced the concept of Multi-targeting. Through a simple drop-down, you can decide if you want a project to target .NET Framework 2.0, 3.0 or 3.5. The builds, the Intellisense, the toolbox, etc. will all adjust to the feature set of the specific version of the .NET Framework which you choose. This allows you to take advantage of the new features in Visual Studio 2008, like the Web design interface, and the improved JavaScript support, and still build your projects for their current runtime version. c# interview questions and answers

C# interview questions and answers

  1. What’s the advantage of using System.Text.StringBuilder over System.String? StringBuilder is more efficient in the cases, where a lot of manipulation is done to the text. Strings are immutable, so each time it’s being operated on, a new instance is created.
  2. Can you store multiple data types in System.Array? No.
  3. What’s the difference between the System.Array.CopyTo() and System.Array.Clone()? The first one performs a deep copy of the array, the second one is shallow.
  4. How can you sort the elements of the array in descending order? By calling Sort() and then Reverse() methods.
  5. What’s the .NET datatype that allows the retrieval of data by a unique key? HashTable.
  6. What’s class SortedList underneath? A sorted HashTable.
  7. Will finally block get executed if the exception had not occurred? Yes.
  8. What’s the C# equivalent of C++ catch (…), which was a catch-all statement for any possible exception? A catch block that catches the exception of type System.Exception. You can also omit the parameter data type in this case and just write catch {}.
  9. Can multiple catch blocks be executed? No, once the proper catch code fires off, the control is transferred to the finally block (if there are any), and then whatever follows the finally block.
  10. Why is it a bad idea to throw your own exceptions? Well, if at that point you know that an error has occurred, then why not write the proper code to handle that error instead of passing a new Exception object to the catch block? Throwing your own exceptions signifies some design flaws in the project.
  11. What’s a delegate? A delegate object encapsulates a reference to a method. In C++ they were referred to as function pointers.
  12. What’s a multicast delegate? It’s a delegate that points to and eventually fires off several methods.
  13. How’s the DLL Hell problem solved in .NET? Assembly versioning allows the application to specify not only the library it needs to run (which was available under Win32), but also the version of the assembly.
  14. What are the ways to deploy an assembly? An MSI installer, a CAB archive, and XCOPY command.
  15. What’s a satellite assembly? When you write a multilingual or multi-cultural application in .NET, and want to distribute the core application separately from the localized modules, the localized assemblies that modify the core application are called satellite assemblies.
  16. What namespaces are necessary to create a localized application? System.Globalization, System.Resources.
  17. What’s the difference between // comments, /* */ comments and /// comments? Single-line, multi-line and XML documentation comments.
  18. How do you generate documentation from the C# file commented properly with a command-line compiler? Compile it with a /doc switch.
  19. What’s the difference between and XML documentation tag? Single line code example and multiple-line code example.
  20. Is XML case-sensitive? Yes, so and are different elements.
  21. What debugging tools come with the .NET SDK? CorDBG – command-line debugger, and DbgCLR – graphic debugger. Visual Studio .NET uses the DbgCLR. To use CorDbg, you must compile the original C# file using the /debug switch.
  22. What does the This window show in the debugger? It points to the object that’s pointed to by this reference. Object’s instance data is shown.
  23. What does assert() do? In debug compilation, assert takes in a Boolean condition as a parameter, and shows the error dialog if the condition is false. The program proceeds without any interruption if the condition is true.
  24. What’s the difference between the Debug class and Trace class? Documentation looks the same. Use Debug class for debug builds, use Trace class for both debug and release builds.
  25. Why are there five tracing levels in System.Diagnostics.TraceSwitcher? The tracing dumps can be quite verbose and for some applications that are constantly running you run the risk of overloading the machine and the hard drive there. Five levels range from None to Verbose, allowing to fine-tune the tracing activities.
  26. Where is the output of TextWriterTraceListener redirected? To the Console or a text file depending on the parameter passed to the constructor.
  27. How do you debug an ASP.NET Web application? Attach the aspnet_wp.exe process to the DbgClr debugger.
  28. What are three test cases you should go through in unit testing? Positive test cases (correct data, correct output), negative test cases (broken or missing data, proper handling), exception test cases (exceptions are thrown and caught properly).
  29. Can you change the value of a variable while debugging a C# application? Yes, if you are debugging via Visual Studio.NET, just go to Immediate window.
  30. Explain the three services model (three-tier application). Presentation (UI), business (logic and underlying code) and data (from storage or other sources).
  31. What are advantages and disadvantages of Microsoft-provided data provider classes in ADO.NET? SQLServer.NET data provider is high-speed and robust, but requires SQL Server license purchased from Microsoft. OLE-DB.NET is universal for accessing other sources, like Oracle, DB2, Microsoft Access and Informix, but it’s a .NET layer on top of OLE layer, so not the fastest thing in the world. ODBC.NET is a deprecated layer provided for backward compatibility to ODBC engines.
  32. What’s the role of the DataReader class in ADO.NET connections? It returns a read-only dataset from the data source when the command is executed.
  33. What is the wildcard character in SQL? Let’s say you want to query database with LIKE for all employees whose name starts with La. The wildcard character is %, the proper query with LIKE would involve ‘La%’.
  34. Explain ACID rule of thumb for transactions. Transaction must be Atomic (it is one unit of work and does not dependent on previous and following transactions), Consistent (data is either committed or roll back, no “in-between” case where something has been updated and something hasn’t), Isolated (no transaction sees the intermediate results of the current transaction), Durable (the values persist if the data had been committed even if the system crashes right after).
  35. What connections does Microsoft SQL Server support? Windows Authentication (via Active Directory) and SQL Server authentication (via Microsoft SQL Server username and passwords).
  36. Which one is trusted and which one is untrusted? Windows Authentication is trusted because the username and password are checked with the Active Directory, the SQL Server authentication is untrusted, since SQL Server is the only verifier participating in the transaction.
  37. Why would you use untrusted verificaion? Web Services might use it, as well as non-Windows applications.
  38. What does the parameter Initial Catalog define inside Connection String? The database name to connect to.
  39. What’s the data provider name to connect to Access database? Microsoft.Access.
  40. What does Dispose method do with the connection object? Deletes it from the memory.
  41. What is a pre-requisite for connection pooling? Multiple processes must agree that they will share the same connection, where every parameter is the same, including the security settings.