Basic Questions Dotnet

CSS

Question: What do u mean to CSS ? Answer: Style sheets are a very powerful tool for the Web site developer. They give you the chance to be completely consistent with the look and feel of your pages, while giving you much more control over the layout and design than straight HTML ever did. Question: What is CSS? Answer: CSS stands for cascading stylesheets Styles define how to display HTML elements Styles are normally stored in Style Sheets Styles were added to HTML 4.0 to solve a problem External Style Sheets can save you a lot of work External Style Sheets are stored in CSS files Multiple style definitions will cascade into one. Question: Style Sheets Can Save a Lot of Work Answer: Enforcing data integrity ensures the quality of the data in the database. For example, if an employee is entered with an employee_id value of 123, the database should not allow another employee to have an ID with the same value. If you have an employee_rating column intended to have values ranging from 1 to 5, the database should not accept a value of 6. If the table has a dept_id column that stores the department number for the employee, the database should allow only values that are valid for the department numbers in the company. Two important steps in planning tables are to identify valid values for a column and to decide how to enforce the integrity of the data in the column. Data integrity falls into these categories. Question: How to add Add External Style Sheet? Answer: An external style sheet is ideal when the style is applied to many pages. With an external style sheet, you can change the look of an entire Web site by changing one file. Each page must link to the style sheet using the tag. The tag goes inside the head section: Question:What is Internal Style Sheet? Answer:An internal style sheet should be used when a single document has a unique style. You define internal styles in the head section by using the <style> tag, like this: <style type="text/css"> hr {color: sienna} p {margin-left: 20px} body {background-image: url("images/back40.gif")} The browser will now read the style definitions, and format the document according to it. Question:What are Inline Styles? Answer: An inline style loses many of the advantages of style sheets by mixing content with presentation. Use this method sparingly, such as when a style is to be applied to a single occurrence of an element. To use inline styles you use the style attribute in the relevant tag. The style attribute can contain any CSS property. The example shows how to change the color and the left margin of a paragraph:

This is a paragraph

Question: When do you use CSS dimension? Answer: The CSS dimension properties allow you to control the height and width of an element. It also allows you to increase the space between two lines.

Question: CSS purpose and Used for? Answer: CSS is a language, separate from HTML or XHTML CSSused to specify the layout or formatting properties of HTML elements From a single CSS file you can control an entire sites: font type ,font and element colour ,padding ,margins ,and element positioning CSS allows developers to separate style (look, appearance,colours, fonts, layout) from the pages structure. Question: What are the CSS Web Template? Answer: "CSS Web Template" is a website design created using Cascading Style Sheets (CSS) technology. Cascading stylesheets provide web developers an easy way to format and to style web pages. CSS will be used even more because it is seen the same way by all browsers, making it the best option during the browser wars

VB.NET QUESTIONS

Question:-What is DataType conversion in VB.NET ? Answer: Convert one variable type to another one is called datatype conversion we can also caleed this casting in VB.NET some automatically conversion is also there. Cbool CByte CChar Cdate CDec CDbl CInt CLng CObj CShort CSng CStr CType Asc. Question:-What do u mean by Redim in VB.NET ? Answer: In vb.net we use Redim and erase to manipulate Array. Once we declare an array the size set to array its makes limited to that range but with the help of redim we used to change the array size. Redim arr(6) we can also used preserve to save these values. Redim Preserve arr(6) Question:- What is branching logic control in vb.net ? Answer: Function and subroutines are the answer.The diffrence in two of them is function send information back from where it is called means function can return a value but subroutines can not do this. Question:-Write the role of New keyword ? Answer: New is used to initialize a new object. We sets a variable to any dattype with help of New keyword .The New keyword gives a value to the variable.We can also uses new keyword to initialize an object variable. Example:- dim obj as new SqlDataAdapter.

SQL SERVER

Question: What are the null values in SQL SERVER ? Answer: Before understand the null values we have some overview about what the value is. Value is the actual data stored in a particular field of particular record. But what is done when there is no values in the field.That value is something like < null>.Nulls present missing information. We can also called null propagation. Question: What are the different types of Locks ? Answer: There are three main types of locks that SQL Server (1)Shared locks are used for operations that does not allow to change or update data, such as a SELECT statement. (2)Update locks are used when SQL Server intends to modify a page, and later promotes the update page lock to an exclusive page lock before actually making the changes. (3)Exclusive locks are used for the data modification operations, such as UPDATE, INSERT, or DELETE. Question: What Is Database ? Answer: A database is similar to a data file in that it is a storage place for data. Like a data file, a database does not present information directly to a user; the user runs an application that accesses data from the database and presents it to the user in an understandable format.Database systems are more powerful than data files in that data is more highly organized. In a well-designed database, there are no duplicate pieces of data that the user or application must update at the same time. Related pieces of data are grouped together in a single structure or record, and relationships can be defined between these structures and records.When working with data files, an application must be coded to work with the specific structure of each data file. In contrast, a database contains a catalog that applications use to determine how data is organized. Generic database applications can use the catalog to present users with data from different databases dynamically, without being tied to a specific data format. A database typically has two main parts: first, the files holding the physical database and second, the database management system (DBMS) software that applications use to access data. The DBMS is responsible for enforcing the database structure, including: · Maintaining relationships between data in the database. Ensuring that data is stored correctly, and that the rules defining data relationships are not violated. · Recovering all data to a point of known consistency in case of system failures. Question: what is Relational Database ? Answer: Although there are different ways to organize data in a database, relational databases are one of the most effective. Relational database systems are an application of mathematical set theory to the problem of effectively organizing data. In a relational database, data is collected into tables (called relations in relational theory). A table represents some class of objects that are important to an organization. For example, a company may have a database with a table for employees, another table for customers, and another for stores. Each table is built of columns and rows (called attributes and tuples in relational theory). Each column represents some attribute of the object represented by the table. For example, an Employee table would typically have columns for attributes such as first name, last name, employee ID, department, pay grade, and job title. Each row represents an instance of the object represented by the table. For example, one row in the Employee table represents the employee who has employee ID 12345. When organizing data into tables, you can usually find many different ways to define tables. Relational database theory defines a process called normalization, which ensures that the set of tables you define will organize your data effectively. Question: What is Data Integrity and it's categories ? Answer: Enforcing data integrity ensures the quality of the data in the database. For example, if an employee is entered with an employee_id value of 123, the database should not allow another employee to have an ID with the same value. If you have an employee_rating column intended to have values ranging from 1 to 5, the database should not accept a value of 6. If the table has a dept_id column that

stores the department number for the employee, the database should allow only values that are valid for the department numbers in the company. Two important steps in planning tables are to identify valid values for a column and to decide how to enforce the integrity of the data in the column. Data integrity falls into these categories: 1) 2) 3) 4)

Entity integrity Domain integrity Referential integrity User-defined integrity

Entity Integrity: Entity integrity defines a row as a unique entity for a particular table. Entity integrity enforces the integrity of the identifier column(s) or the primary key of a table (through indexes, UNIQUE constraints, PRIMARY KEY constraints, or IDENTITY properties). Domain Integrity: Domain integrity is the validity of entries for a given column. You can enforce domain integrity by restricting the type (through data types), the format (through CHECK constraints and rules), or the range of possible values (through FOREIGN KEY constraints, CHECK constraints, DEFAULT efinitions, NOT NULL definitions, and rules). Referential Integrity: Referential integrity preserves the defined relationships between tables when records are entered or deleted. In Microsoft® SQL Server™ 2000, referential integrity is based on relationships between foreign keys and primary keys or between foreign keys and unique keys (through FOREIGN KEY and CHECK constraints). Referential integrity ensures that key values are consistent across tables. Such consistency requires that there be no references to nonexistent values and that if a key value changes, all references to it change consistently throughout the database. When you enforce referential integrity, SQL Server prevents users from: · Adding records to a related table if there is no associated record in the primary table. · Changing values in a primary table that result in orphaned records in a related table. · Deleting records from a primary table if there are matching related records. For example, with the sales and titles tables in the pubs database, referential integrity is based on the relationship between the foreign key (title_id) in the sales table and the primary key (title_id) in the titles table. User-Defined: Integrity User-defined integrity allows you to define specific business rules that do not fall into one of the other integrity categories. All of the integrity categories support user-defined integrity (all column- and table-level constraints in CREATE TABLE, stored procedures, and triggers). Question: SQL Server runs on which TCP/IP port and From where can you change the default port? Answer: SQL Server runs on port 1433 but we can also change it for better security and From the network Utility TCP/IP properties -->Port number.both on client and the server. Question: What is the use of DBCC commands? Answer: DBCC stands for database consistency checker. We use these commands to check the consistency of the databases, i.e., maintenance, validation task and status checks.DBCC CHECKDB Ensures that tables in the db and the indexes are correctly linked.and DBCC CHECKALLOC To check that all pages in a db are correctly allocated. DBCC SQLPERF - It gives report on current usage of transaction log in percentage. DBCC CHECKFILEGROUP - Checks all tables file group for any damage. Question: What is the difference between a HAVING CLAUSE and a WHERE CLAUSE? Answer: Having Clause is basically used only with the GROUP BY function in a query. WHERE Clause is applied to each row before they are part of the GROUP BY function in a query. Question: When do you use SQL Profiler? Answer: SQL Profiler utility allows us to basically track Connections to the SQL Server and also determine activities such as which SQL Scripts are running, failed jobs etc. Question: Can you explain the role of each service? Answer: SQL SERVER - is for running the databases SQL AGENT - is for automation such as Jobs, DB Maintenance, Backups DTC - Is for linking and connecting to other SQL Servers.

Question: What is Normalization ? Answer: The logical design of the database, including the tables and the relationships between them, is the core of an optimized relational database. A good logical database design can lay the foundation for optimal database and application performance. A poor logical database design can impair the performance of the entire system. Normalizing a logical database design involves using formal methods to separate the data into multiple, related tables. A greater number of narrow tables (with fewer columns) is characteristic of a normalized database. A few wide tables (with more columns) is characteristic of an nonnomalized database. Reasonable normalization often improves performance. When useful indexes are available, the Microsoft® SQL Server™ 2000 query optimizer is efficient at selecting rapid, efficient joins between tables. Some of the benefits of normalization include: ·Faster sorting and index creation. ·A larger number of clustered indexes. For more information, Narrower and more compact indexes. ·Fewer indexes per table, which improves the performance of INSERT, UPDATE, and DELETE statements. ·Fewer null values and less opportunity for inconsistency, which increase database compactness. As normalization increases, so do the number and complexity of joins required to retrieve data. Too many complex relational joins between too many tables can hinder performance. Reasonable normalization often includes few regularly executed queries that use joins involving more than four tables. Sometimes the logical database design is already fixed and total redesign is not feasible. Even then, however, it might be possible to normalize a large table selectively into several smaller tables. If the database is accessed through stored procedures, this schema change could take place without affecting applications. If not, it might be possible to create a view that hides the schema change from the applications. Question: Can you tell me the difference between DELETE &TRUNCATE commands? Answer: Delete command removes the rows from a table based on the condition that we provide with a WHERE clause. Truncate will actually remove all the rows from a table and there will be no data in the table after we run the truncate command.

OOPS Question: What Is OOPS ? Answer: OOPs is an Object Oriented Programming language,which is the extension of Procedure Oriented Programming language.OOPS reduce the code of the program because of the extensive feature of Polymorphism. OOPS have many properties such as Data-Hiding,Inheritence,Data Absraction,Data Encapsulation and many moreEverything in the world is an object. The type of the object may vary. In OOPS, we get the power to create objects of our own, as & when required. Question: what is Class ? Answer:A group of objects that share a common definition and that therefore share common properties, operations, and behavior. A user-defined type that is defined with the class-key 'class,' 'struct,' or 'union.' Objects of a class type consist of zero or more members and base class objects.Classes can be defined hierarchically, allowing one class to be an expansion of another, and classes can restrict access to their members. Question: What is Constructor? Answer:When we create instance of class a special method of that class, called that is constructor. Similarly, when the class is destroyed, the destructor method is called. These are general terms and usually not the actual member names in most object-oriented languages. It is initialized using the keyword New, and is destroyed using the keyword Finalize. Question: What is Abstract Class ? Answer:Classes that cannot be instantiated. We cannot create an object from such a class for use in our program. We can use an abstract class as a base class, creating new classes that will inherit from it. Creating an abstract class with a certain minimum required level of functionality gives us a defined starting point from which we can derive non-abstract classes. An abstract class may contain abstract methods & non-abstract methods. When a class is derived from an abstract class, the derived class must implement all the abstract methods declared in the base class. We may use accessibility modifiers in an abstract class.An abstract class can inherit from a non-abstract class. In C++, this concept is known as pure virtual method. Question: What is ValueType? Answer:Value Types - Value types are primitive types. Like Int32 maps to System.Int32, double maps to System.double.All value types are stored on stack and all the value types are derived from System.ValueType. All structures and enumerated types that are derived from System.ValueType are created on stack, hence known as ValueType.In value type we create a copy of object and uses there value its not the original one. Question: What is diff. between abstract class and an interface? Answer: An abstract class and Interface both have method only but not have body of method.The difference between Abstract class and An Interface is that if u call Ablstract class then u have to call all method of that particular Abstract class but if u call an Interface then it is not necessary that u call all method of that particular interface.Method OverLoading:-Return type, Parameter type, parameter and body of method number may be different.Method Overriding:- Return type, Parameter type, Parameter Number all must be same . Only body of method can change.

ADO.NET Question: What is Asynchronous Database Commands ? Answer:- When we execute any database. Thread that executing the command waits before the command get fully executing before executing any additional code. Thread is blocked for another process. But Asynchronous Database Commands solve this problem when database command is executing the current thread can continue on other process.Thread can execute a no of database command. There are two benefits of using Asynchronous Database Commands. 1) Executing Multiple Databse Commands simultaneously improve performance. 2) Because ASP.Net framework uses a limited pool service for request. Whenany request for a page is comes its assign a thread to handle the request. If framework is out of thread then job is in gueses we get error 503. But if we are using asynchronous database command then current thread is release back to current thread pool. Question:-What is Concurrency and its types? Answer: When two or more people try to update same type of data then Concurrency helps how to handle this situation there are two types of concurrency:pessimistic and optiimistic. Pessimistic:-When one user try to change the data with pessimistic concurrency a lock is placed on the data so that another user cannot change that one after one another can change. Optimistic:-In this if two user works on the same data and one change that data first then second user cannot change that same data becasue the which he have using is allready changed so he cannot do the change becasue change apply to another data that is changed by first user. Question:-Why is ADO.NET serialization slower than ADO ? Answer: ADO uses binary serialization while ADO.NET uses text based serialization. Since the text takes more space, it takes longer to write it out.

Question:- How to check if the Dataset has records ? Answer: if ds.Tables(0).Rows.Count= 0 then 'No record else 'record found Question:- What is the significance of CommandBehavior.CloseConnection ? Answer: To avoid having to explicitly close the connection associated with the command used to create either a SqlDataReader or and OleDbDataReader, pass the CommandBehavior.CloseConnection argument to the ExecuteReader method of the Connection. dr= cmd.ExecuteReader(CommandBehavior.CloseConnection); The associated connection will be closed automatically when the Close method of the Datareader is called. This makes it all the more important to always remember to call Close on your datareaders. Question:-Which method do you invoke on the DataAdapter control to load your generated dataset with data? Answer: The Fill() method. Question:-What is Dataset and Diffgram? Answer: When sending and retrieving a DataSet from an XML Web service, the DiffGram format is

implicitly used. Additionally, when loading the contents of a DataSet from XML using the ReadXml method, or when writing the contents of a DataSet in XML using the WriteXml method, you can select that the contents be read or written as a DiffGram. For more information, see Loading a DataSet from XML and Writing a DataSet as XML Data. While the DiffGram format is primarily used by the .NET Framework as a serialization format for the contents of a DataSet, you can also use DiffGrams to modify data in tables in a Microsoft SQL Server™ 2000 database. Question:-What is typed dataset ? Answer: A typed dataset is very much similar to a normal dataset. But the only difference is that the sehema is already present for the same. Hence any mismatch in the column will generate compile time errors rather than runtime error as in the case of normal dataset. Also accessing the column value is much easier than the normal dataset as the column definition will be available in the schema. Question:-How can you provide an alternating color scheme in a Repeater control? Answer: AlternatingItemTemplate Like the ItemTemplate element, but rendered for every other row (alternating items) in the Repeater control. You can specify a different appearance for the AlternatingItemTemplate element by setting its style properties. Question:-What are good ADO.NET object(s) to replace the ADO Recordset object? Answer: There are alot...but the base once are SqlConnection, OleDbConnection, etc... Question:-Can you explain the difference between an ADO.NET Dataset and an ADO Recordset? Answer:Valid answers are:

• • • • • • •

A DataSet can represent an entire relational database in memory, complete with tables, relations, and views. A DataSet is designed to work without any continuing connection to the original data source. Data in a DataSet is bulk-loaded, rather than being loaded on demand. There's no concept of cursor types in a DataSet. DataSets have no current record pointer You can use For Each loops to move through the data. You can store many edits in a DataSet, and write them to the original data source in a single operation. Though the DataSet is universal, other objects in ADO.NET come in different versions for different data sources.

Question:-What are the differences between Datalist DataGrid and datarepeater ? Answer:DataList

• • • • • • • • •

Has table appearence by default Has no autoformat option has no default paging & sorting options can define separators between elements using template DataGrid Has a grid appearence by default has a autoformat option has default paging and sorting has no separator between elements DataRepeater simple,read-only output, has no built in support for selecting or editing items, has no DEFAULT APPEARENCE, has no default paging.

ASP.NET BASIC Question: What is late binding ? Answer: When code interacts with an object dynamically at runtime .because our code literally doesnot care what type of object it is interacting and with the methods thats are supported by object and with the methods thats are supported by object .The type of object is not known by the IDE or compiler ,no Intellisense nor compile-time syntax checking is possible but we get unprecedented flexibilty in exchange.if we enable strict type checking by using option strict on at the top of our code modules ,then IDE and compiler will enforce early binding behaviour .By default Late binding is done. Question: What is CSU and its description ? Answer: CSU stands for comma separate values also called comma delimited.It is plain text file which stores spreadsheets or basic datatype in very simple format.One record in each line and each field separted with comma's it is often used to transfer large ammount spreadsheet data or database information between program. Question: The IHttpHandler and IHttpHandlerFactory interfaces ? Answer: The IHttpHandler interface is implemented by all the handlers. The interface consists of one property called IsReusable. The IsReusable property gets a value indicating whether another request can use the IHttpHandler instance. The method ProcessRequest() allows you to process the current request. This is the core place where all your code goes. This method receives a parameter of type HttpContext using which you can access the intrinsic objects such as Request and Response. The IHttpHandlerFactory interface consists of two methods - GetHandler and ReleaseHandler. The GetHandler() method instantiates the required HTTP handler based on some condition and returns it back to ASP.NET. The ReleaseHandler() method allows the factory to reuse an existing handler. Question: what is Viewstate? Answer:View state is used by the ASP.NET page framework to automatically save the values of the page and of each control just prior to rendering to the page. When the page is posted, one of the first tasks performed by page processing is to restore view state. State management is the process by which you maintain state and page information over multiple requests for the same or different pages. Client-side options are: * The ViewState property * Hidden fields

* Query strings * Cookies

Server-side options are: * Application state

* Session state

* DataBase

Use the View State property to save data in a hidden field on a page. Because ViewState stores data on the page, it is limited to items that can be serialized. If you want to store more complex items in View State, you must convert the items to and from a string. ASP.NET provides the following ways to retain variables between requests:

Context.Handler object Use this object to retrieve public members of one Web form’s class from a subsequently displayed Web form. Query strings Use these strings to pass information between requests and responses as part of the Web address. Query strings are visible to the user, so they should not contain secure information such as passwords. Cookies Use cookies to store small amounts of information on a client. Clients might refuse cookies, so your code has to anticipate that possibility. View state ASP.NET stores items added to a page’s ViewState property as hidden fields on the page. Session state Use Session state variables to store items that you want keep local to the current session (single user). Application state Use Application state variables to store items that you want be available to all users of the application. Question: DOTNET PAGE LIFECYCLE ? Answer: While excuting the page, it will go under the fallowing steps(or fires the events) which collectivly known as Page Life cycle. Page_Init -- Page Initialization LoadViewState -- View State Loading LoadPostData -- Postback data processing Page_Load -- Page Loading RaisePostDataChangedEvent -- PostBack Change Notification RaisePostBackEvent -- PostBack Event Handling Page_PreRender -- Page Pre Rendering Phase SaveViewState -- View State Saving Page_Render -- Page Rendering Page_UnLoad -- Page Unloading Question: What is Satellite Assemblies ? Answer: Satellite assemblies are often used to deploy language-specific resources for an application. These language-specific assemblies work in side-by-side execution because the application has a separate product ID for each language and installs satellite assemblies in a language-specific subdirectory for each language. When uninstalling, the application removes only the satellite assemblies associated with a given language and .NET Framework version. No core .NET Framework files are removed unless the last language for that .NET Framework version is being removed. For example, English and Japanese editions of the .NET Framework version 1.1 share the same core files. The Japanese .NET Framework version 1.1 adds satellite assemblies with localized resources in a \ja subdirectory. An application that supports the .NET Framework version 1.1, regardless of its language, always uses the same core runtime files. Question: What is CAS ? Answer:CAS: CAS is the part of the .NET security model that determines whether or not a piece of code is allowed to run, and what resources it can use when it is running. For example, it is CAS that will prevent a .NET web applet from formatting your hard disk. How does CAS work? The CAS security policy revolves around two key concepts - code groups and permissions. Each .NET assembly is a member of a particular code group, and each code group is granted the permissions specified in a named permission set. For example, using the default security policy, a control downloaded from a web site belongs to the 'Zone Internet' code group, which adheres to the permissions defined by the 'Internet' named permission set. (Naturally the 'Internet' named permission set represents a very restrictive range of permissions.) Question: Automatic Memory Management ? Answer: Automatic Memory Management: From a programmer's perspective, this is probably the single biggest benefit of the .NET Framework. No, I'm not kidding. Every project I've worked on in my long career of DOS and Windows development has suffered at some point from memory management issues. Proper memory management is hard. Even very good programmers have difficulty with it. It's entirely too easy for a small mistake to cause a program to chew up memory and crash, sometimes bringing the operating system to a screeching halt in the process. Programmers understand that they're responsible for releasing any memory that they allocate, but they're not very good at actually doing it. In addition, functions that allocate memory as a side effect abound in

the Windows API and in the C runtime library. It's nearly impossible for a programmer to know all of the rules. Even when the programmer follows the rules, a small memory leak in a support library can cause big problems if called enough. The .NET Framework solves the memory management problems by implementing a garbage collector that can keep track of allocated memory references and release the memory when it is no longer referenced. A large part of what makes this possible is the blazing speed of today's processors. When you're running a 2 GHz machine, it's easy to spare a few cycles for memory management. Not that the garbage collector takes a huge number of cycles--it's incredibly efficient. The garbage collector isn't perfect and it doesn't solve the problem of mis-managing other scarce resources (file handles, for example), but it relieves programmers from having to worry about a huge source of bugs that trips almost everybody up in other programming environments. On balance, automatic memory management is a huge win in almost every situation. Question: What Language familar to CLR? Answer: Any language that can be compiled into Microsoft Intermediate Language (MSIL) is considered a .NET-compliant language. Following are a few of the popular .NET-compliant languages supported by CLR: APL Fortran Oberon Smalltalk

COBOL Haskell Pascal Visual Basic

Component Pascal JScript Perl Visual C#

Eiffel Mercury Python Visual C++

WEB SERVICES Question: Define Protocols that helps Web Services ? Answer: From my point of view Web Services used three protocols for interacting with the clients.HttpPost,Http-Get,SOAP. Question: Explain functioning of Web Services Protocols ? Answer: Http-Get:- This is standard protocol that helps client to communicate with server with HTTP.When client send a request to server via HTTP request and reuired parameter are attached with the querystring.Example:http://www.dotnetquestion.info/dotnet/interview.aspx?id=pervej&cast=munjal and we get the value from querystring. Request.querystring("id") Request.querystring("cast"). Http-Post:-This is same as Http-Get but the diffrence is that in place of sending parameters onto the URL information is send with HTTP request message with some extra information which contains Parameters and their values.This Protocols is limited to sending name/value pairs. SOAP:-The only diffrence is that its relies on the XML as compares to Http-Get,Http-Post.SOAP can send not only the name/value pairs but also some complex object also as for example datatypes,class,objects.SOAP can also uses request/reponse model as Http-Get,Http-post but it is not limited to Request/Response it can also send types of message.Because its uses XML that is pure text so firewalls not created so much problem because its easily converted in to HTML. . Question: Why do some web service classes derive from System.Web.WebServices while others do not ? Answer: Those Web Service classes which employ objects like Application, Session, Context, Server, and User have to derive from System.Web.WebServices. If it does not use these objects, it is not necessary to be derived from it. Question: What is WSDL ? Answer: WSDL is an XML format for describing network services as a set of endpoints operating on messages containing either document-oriented or procedure-oriented information. The operations and messages are described abstractly, and then bound to a concrete network protocol and message format to define an endpoint. Related concrete endpoints are combined into abstract endpoints (services). (Source: www.w3.org). Question: What is the standard you use to wrap up a call to a Web service ? Answer: HTTP with SOAP. Question: Explain Web Services ? Answer: Web services are programmable business logic components that provide access to functionality through the Internet. Standard protocols like HTTP can be used to access them. Web services are based on the Simple Object Access Protocol (SOAP), which is an application of XML. Web services are given the .asmx extension.. Question: What are VSDISCO files ? Answer: VSDISCO files are DISCO files that enable dynamic discovery of Web Services. ASP.NET links the

VSDISCO to a HTTP handler that scans the host directory and subdirectories for ASMX and DISCO files and returns a dynamically generated DISCO document. A client who requests a VSDISCO file gets back what appears to be a static DISCO document. Question: What is UDDI ? Answer: UDDI stands for Universal Description, Discovery, and Integration. It is like an "Yellow Pages" for Web Services. It is maintained by Microsoft, IBM, and Ariba, and is designed to provide detailed information regarding registered Web Services for all vendors. The UDDI can be queried for specific Web Services. Question: Is it possible to generate the source code for an ASP.NET Web service from a WSDL ? Answer: The Wsdl.exe tool (.NET Framework SDK) can be used to generate source code for an ASP.NET web service with its WSDL link. Example: wsdl /server http://api.google.com/GoogleSearch.wsdl. Question: Can you give an example of when it would be appropriate to use a web service as opposed to a non-serviced .NET component ? Answer: When to Use Web Services: (i)Communicating through a Firewall When building a distributed application with 100s/1000s of users spread over multiple locations, there is always the problem of communicating between client and server because of firewalls and proxy servers. Exposing your middle tier components as Web Services and invoking the directly from a Windows UI is a very valid option. (ii)Application Integration When integrating applications written in various languages and running on disparate systems. Or even applications running on the same platform that have been written by separate vendors. (iii)Business-to-Business Integration This is an enabler for B2B intergtation which allows one to expose vital business processes to authorized supplier and customers. An example would be exposing electronic ordering and invoicing, allowing customers to send you purchase orders and suppliers to send you invoices electronically. (iv)Software Reuse This takes place at multiple levels. Code Reuse at the Source code level or binary componet-based resuse. The limiting factor here is that you can reuse the code but not the data behind it. Webservice overcome this limitation. A scenario could be when you are building an app that aggregates the functionality of serveral other Applicatons. Each of these functions could be performed by individual apps, but there is value in perhaps combining the the multiple apps to present a unifiend view in a Portal or Intranet. Question: What are Service Oriented Architectures (SOA) ? Answer: 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. Question: What is .NET Passport ? Answer: .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.