ASP.NET (part-II) interview question and answers

Describe the role of inetinfo.exe, aspnet_isapi.dll and aspnet_wp.exe in the page loading process ?

inetinfo.exe is the Microsoft 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 to the actual worker process
aspnet_wp.exe.

What’s the difference between Response.Write() and Response.Output.Write()?

Response.Output.Write() allows you to write formatted output.

What methods are fired during the page load?

Init() - when the page is instantiatedLoad() - when the page is loaded into server memoryPreRender() - the brief moment before the page is displayed to the user as HTMLUnload() - when page finishes loading.

When during the page processing cycle is ViewState available?

After the Init() and before the Page_Load(), or OnLoad() for a control.

What namespace does the Web page belong in the .NET Framework class hierarchy?

System.Web.UI.Page

Where do you store the information about the user’s locale?

System.Web.UI.Page.Culture

What’s the difference between Codebehind="MyCode.aspx.cs" and Src="MyCode.aspx.cs"?

CodeBehind is relevant to Visual Studio.NET only.

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 event
handlers, allowing the main DataGrid event handler to take care of its constituents.
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();");

What data types do the RangeValidator control support?

Integer, String, and Date.

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.

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.

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.

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 perform as 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.

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.

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.

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.

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.

What is an assembly?

Assemblies are the building blocks of the .NET framework.
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

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.

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.

Which method do you invoke on the DataAdapter control to load your generated dataset with data?

The Fill() method.

Can you edit data in the Repeater control?

No, it just reads the information from its data source.

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

ItemTemplate.