Asp Faqs

1.What are steps in an asp .net page lifecycle?
Init() - when the page is instantiated
Load() - when the page is loaded into server

memory
PreRender() - the brief moment before the page is displayed to the user as HTML
Unload() - when page finishes loading.

2.What is the main difference between Response.Write() and Response.Output.Write()?
With Response.Outout.Write options are available to you to write the formatted out put.

3.When implementing classes what are the specifics of an abstract method?
An Abstract method does not provide any implementation. The class containing it can not be instantiated it must be inherited. The deriving class must override abstract methods declared in parent class, unless it is an abstract class it self.

4.List all Validation Controls available in asp .net?
RequiredFieldValidator : Checks if a control has a value.
RangeValidator : Checks if the control’s value is within a certain range.
RegularExpressionValidator : Checks whether the value of an input control matches a certain pattern
CompareValidator : Checks a control’s value against a constant or another control value.
CustomValidator : Checks a control’s value against a customized validation logic.
ValidationSummary : Displays a list of all validation errors

5.What data types do the RangeValidator control support?
Integer, String, and Date.

6.Is C# .net case sensitive?
Yes it is.

7.What is the difference between a class and struct ?
A struct is a value type while a class is a reference type. There’s no inheritance with
struct.

8.When passing a variable by reference to a method what is the difference between keywords ref and out?
When using the key word ref the variable must be initialize before calling the method,
while initialization is not mandatory when using out.

9.What are specifics for Static class?
Static class is implemented with the Keyword Static in the class definition.
It must contain only static members and methods. Public members of static class can be accessed without the class instantiation. Static class are sealed by default therefore can not be inherited. Static class cannot be instantiated.

10.What part of the code is usually called Code-Behind?
The Server side code is usually called Code-behind as reference to the fact that in a web application it is actually the part of the code handling the large part of the execution.

11.What part of the code is called Inline Code?
The asp .net client side code is usually call inline code. From most browsers it can be
view by choosing 'View source' from the page menu.

12.What is the difference between doing a Dataset.Clone() and Dataset.Copy()?
Dataset.Clone() will copy just the dataset structure including all the datatables,
schemas, relations and constraints; it will not copy the data. Dataset.Copy() will copy
both dataset structure and data.

13.What is the role of Global.asax file?
The Global.asax include its code behind file Global.asax.cs, it is use to implement
application and session level events.

14.What utility is used to manually deploy an assembly?
The GacUtil is a utility tool that comes with visual studio, it is use to deploy an
assembly by adding it into the GAC(Global Assembly Cache).

Ex: Type at the command line prompt
C:\gacutil /i ASPMyComponent.dll
will install ASPMyComponent into the GAC

15.Define MSIL. How is it use in the .Net framework?
MSIL stand for Microsoft Intermediate Language. During the compilation process, code written in any .NET compatible languages(J#, C#, VB,C++) is converted into MSIL. MSIL then create a compatibility bridge among these language before execution by the virtual machine.

16. What are differences between ASP.Net and Classic ASP?
-ASP programming is based on scripting languages like Jscript or VBScript which evolves around a mixture of scripting and HTML. ASP .net is base on an advance structured compiled language.
-ASP .net gives the option of separating the code behind (compiled code) from the design code or client code (HTML).
-ASP .net with visual studio .net provides an advanced application and session state
management, while ASP performs poorly at providing it.
-ASP has a poor error handling capability compare to ASP .net which has it much completed and much advanced.
-ASP does not have a built-in mechanism for XML while ASP .net comes with a full XML capability support.
-ASP .net has a fully distributed data source support which is missing from classic ASP

17.What property is use to set alternate color scheme in a Repeater control?
AlternatingItemTemplate.

18.What is the base class for Web Forms?
The System.Web.UI.Page class.

19.What are the meaning of terms boxing and un-boxing?
Boxing: Implicit conversion of a value type into a reference type.
Un-Boxing: Explicit conversion of a reference type into a value type. Can also be call
casting.

20.Give a brief description of how the heap and stack are managed in .Net.
Stack and heap are memory sections of the .net application. The CLR(Common Language Runtime) is in charge of managing those sections.
Value type variables are stored in the stack where storing order is Last in first out.
When a variable is out of scope it basically fall off the stack.
Refence type variable are stored on the heap where storing order is First in first out.
When a variable becomes out of scope it is mark for collection.

The GC(Garbage Collector) is the part of the CLR responsible for cleaning up the heap releasing resources occupied by Reference type variables.

1. Describe the role of inetinfo.exe, aspnet_isapi.dll andaspnet_wp.exe in the page loading process.
inetinfo.exe is theMicrosoft IIS server running, handling ASP.NET requests among other things.When an ASP.NET request is received (usually a file with .aspx extension), the ISAPI filter aspnet_isapi.dll takes care of it by passing the request tothe actual worker process aspnet_wp.exe.

2. What’s the difference between Response.Write() andResponse.Output.Write()?
Response.Output.Write() allows you to write formatted output.

3. What methods are fired during the page load?
Init() - when the page is instantiated
Load() - when the page is loaded into server memory
PreRender() - the brief moment before the page is displayed to the user as HTML
Unload() - when page finishes loading.

4. When during the page processing cycle is ViewState available?
After the Init() and before the Page_Load(), or OnLoad() for a control.

5. What namespace does the Web page belong in the .NET Framework class hierarchy?
System.Web.UI.Page

6. Where do you store the information about the user’s locale?
System.Web.UI.Page.Culture

7. What’s the difference between Codebehind="MyCode.aspx.cs" andSrc="MyCode.aspx.cs"?
CodeBehind is relevant to Visual Studio.NET only.

8. What’s a bubbled event?
When you have a complex control, like DataGrid, writing an event processing routine for each object (cell, button, row, etc.) is quite tedious. The controls can bubble up their eventhandlers, allowing the main DataGrid event handler to take care of its constituents.

9. Suppose you want a certain ASP.NET function executed on MouseOver for a certain button. Where do you add an event handler?
Add an OnMouseOver attribute to the button. Example: btnSubmit.Attributes.Add("onmouseover","someClientCodeHere();");

10. What data types do the RangeValidator control support?
Integer, String, and Date.

11. Explain the differences between Server-side and Client-side code?
Server-side code executes on the server. Client-side code executes in the client's browser.

12. What type of code (server or client) is found in a Code-Behind class?
The answer is server-side code since code-behind is executed on the server. However, during the code-behind's execution on the server, it can render client-side code such ///as JavaScript to be processed in the clients browser. But just to be clear, code-behind executes on the server, thus making it server-side code.

13. Should user input data validation occur server-side or client-side? Why?
All user input data validation should occur on the server at a minimum. Additionally, client-side validation can be performed where deemed appropriate and feasable to provide a richer, more responsive experience for the user.

14. What is the difference between Server.Transfer and Response.Redirect? Why would I choose one over the other?
Server.Transfer transfers page processing from one page directly to the next page without making a round-trip back to the client's browser. This provides a faster response with a little less overhead on the server. Server.Transfer does not update the clients url history list or current url. Response.Redirect is used to redirect the user's browser to another page or site. This performs a trip back to the client where the client's browser is redirected to the new page. The user's browser history list is updated to reflect the new address.

15. Can you explain the difference between an ADO.NET Dataset and an ADO Recordset?
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.

16. What is the Global.asax used for?
The Global.asax (including the Global.asax.cs file) is used to implement application and session level events.

17. What are the Application_Start and Session_Start subroutines used for?
This is where you can set the specific variables for the Application and Session objects.

18. Can you explain what inheritance is and an example of when you might use it?
When you want to inherit (use the functionality of) another class. Example: With a base class named Employee, a Manager class could be derived from the Employee base class.

19. Whats an assembly?
Assemblies are the building blocks of the .NET framework. Overview of assemblies from MSDN

20. Describe the difference between inline and code behind.
Inline code written along side the html in a page. Code-behind is code written in a separate file and referenced by the .aspx page.

21. Explain what a diffgram is, and a good use for one?
The DiffGram is one of the two XML formats that you can use to render DataSet object contents to XML. A good use is reading database data to an XML file to be sent to a Web Service.

22. Whats MSIL, and why should my developers need an appreciation of it if at all?
MSIL is the Microsoft Intermediate Language. All .NET compatible languages will get converted to MSIL. MSIL also allows the .NET Framework to JIT compile the assembly on the installed computer.

23. Which method do you invoke on the DataAdapter control to load your generated dataset with data?
The Fill() method.

24. Can you edit data in the Repeater control?
No, it just reads the information from its data source.

25. Which template must you provide, in order to display data in a Repeater control?
ItemTemplate.

26. How can you provide an alternating color scheme in a Repeater control?
Use the AlternatingItemTemplate.

27. What property must you set, and what method must you call in your code, in order to bind the data from a data source to the Repeater control?
You must set the DataSource property and call the DataBind method.

28. What base class do all Web Forms inherit from?
The Page class.

29. Name two properties common in every validation control?
ControlToValidate property and Text property.

30. Which property on a Combo Box do you set with a column name, prior to setting the DataSource, to display data in the combo box?
DataTextField property.

31. Which control would you use if you needed to make sure the values in two different controls matched?
CompareValidator control.

32. How many classes can a single .NET DLL contain?
It can contain many classes.

Web Service Questions

1. What is the transport protocol you use to call a Web service?
SOAP (Simple Object Access Protocol) is the preferred protocol.

2. True or False: A Web service can only be written in .NET?
False

3. What does WSDL stand for?
Web Services Description Language.

4. Where on the Internet would you look for Web services?
http://www.uddi.org

5. True or False: To test a Web service you must create a Windows application or Web application to consume this service?
False, the web service comes with a test page and it provides HTTP-GET method to test.

State Management Questions

1. What is ViewState?
ViewState allows the state of objects (serializable) to be stored in a hidden field on the page. ViewState is transported to the client and back to the server, and is not stored on the server or any other external source. ViewState is used the retain the state of server-side objects between postabacks.

2. What is the lifespan for items stored in ViewState?
Item stored in ViewState exist for the life of the current page. This includes postbacks (to the same page).

3. What does the "EnableViewState" property do? Why would I want it on or off?
It allows the page to save the users input on a form across postbacks. It saves the server-side values for a given control into ViewState, which is stored as a hidden value on the page before sending the page to the clients browser. When the page is posted back to the server the server control is recreated with the state stored in viewstate.

4. What are the different types of Session state management options available with ASP.NET?
ASP.NET provides In-Process and Out-of-Process state management. In-Process stores the session in memory on the web server. This requires the a "sticky-server" (or no load-balancing) so that the user is always reconnected to the same web server. Out-of-Process Session state management stores data in an external data source. The external data source may be either a SQL Server or a State Server service. Out-of-Process state management requires that all objects stored in session are serializable.