ASP.Net Questions & Answers

1. Explain the differences between Server-side and Client-side code?
Client side is what's happening on your computer in your browser. It has nothing to do with the server, or ASP or ASPX pages, or IIS, or the database, or ANYTHING ELSE. JavaScript in a web page would be an example of something client side.
Server side is when the server is being used to process something. Script or code that is run on the server does NOT appear on or in the web page that is sent to your browser -- the web page that your browser receives is only the RESULT of the script or database code or processing that happened on the server.

2. What type of code (server or client) is found in a Code-Behind class?
usually codebehind files are being used to write server side events.But you can write client side events/script like javascript by using RegisterClientScirptBlock

3. Should validation (did the user enter a real date) occur server-side or client-side? Why?
This validation should coccur at the client side, cause its easy to validate in the client side rather than shooting it all the way to the server, which increase procesign time, and all unneccssary delays.

4. What does the "EnableViewState" property do? Why would I want it on or off?
It allows page objects to save their state in a Base64 encoded string in the page HTML. One should only have it enabled when needed because it adds to the page size and can get fairly large for complex pages with many controls. (It takes longer to download the page).

5. What is the difference between Server.Transfer and Response.Redirect? Why would I choose one over the other?
Server.Transfer transfers excution directly to another page. Response.Redirect sends a response to the client and directs the client (the browser) to load the new page (it causes a roundtrip). If you don't need to execute code on the client, Transfer is more efficient.

6. Can you give an example of when it would be appropriate to use a web service as opposed to a non-serviced .NET component

7. Let's say I have an existing application written using Visual Studio 6 (VB 6, InterDev 6) and this application utilizes Windows 2000 COM+ transaction services. How would you approach migrating this application to .NET


8. 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.

9. Can you give an example of what might be best suited to place in the Application_Start and Session_Start subroutines?
This is where you can set the specific variables for the Application and Session objects.

10. If I'm developing an application that must accomodate multiple security levels though secure login and my ASP.NET web appplication is spanned across three web-servers (using round-robbin load balancing) what would be the best approach to maintain login-in state for the
users?
11. What are ASP.NET WebForms? How is this technology different than what is available though ASP (1.0-3.0)?
12. How does VB.NET/C# achieve polymorphism?
11. Can you explain what inheritance is and an example of when you might use it?
13. How would you implement inheritance using VB.NET/C#?
14. Whats an assembly
15. Describe the difference between inline and code behind - which is best in a loosely coupled solution
17. Explain what a diffgram is, and a good use for one
18. Where would you use an iHTTPModule, and what are the limitations of any approach you might take in implementing one
20. What are the disadvantages of viewstate/what are the benefits
21 Describe session handling in a webfarm, how does it work and what are the > limits
22. How would you get ASP.NET running in Apache web servers - why would you even do this?
23. Whats MSIL, and why should my developers need an appreciation of it if at all?
24. In what order do the events of an ASPX page execute. As a developer is it important to undertsand these events?
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.

25. Which method do you invoke on the DataAdapter control to load your generated dataset with data?
Fill()
26. Can you edit data in the Repeater control?
No
27. Which template must you provide, in order to display data in a Repeater control?
ItemTemplate
28. How can you provide an alternating color scheme in a Repeater control?
Use the AlternatingItemTemplate.

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

30. What base class do all WebForms inherit from?
The Page class.
31. What method do you use to explicitly kill a user s session?

32 How do you turn off cookies for one page in your site?
33. Which two properties are on every validation control?
ControlToValidate property and Text property.

34. What tags do you need to add within the asp:datagrid tags to bind columns manually?
35. How do you create a permanent cookie?
36. What tag do you use to add a hyperlink column to the DataGrid?
37. What is the standard you use to wrap up a call to a Web service
38. Which method do you use to redirect the user to another page without performing a round trip to the client?
39. What is the transport protocol you use to call a Web service ?
SOAP (Simple Object Access Protocol) is the preferred protocol.

40. True or False: A Web service can only be written in .NET
False
41. What does WSDL stand for?
Web Services Description Language
WSDL is written in XML - it is an XML-based language
WSDL is an XML document
WSDL is used to describe Web services (ie. the operations (or methods) the service exposes)
WSDL is also used to locate Web services
WSDL is not yet a W3C standard

42. What property do you have to set to tell the grid which page to go to when using the Pager object?
43. Where on the Internet would you look for Web services?
http://www.uddi.org/
44. What tags do you need to add within the asp:datagrid tags to bind columns manually.

45. 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?
46. How is a property designated as read-only?
47. Which control would you use if you needed to make sure the values in two different controls matched?
CompareValidator

48. True or False: To test a Web service you must create a windows application or Web application to consume this service?
49. How many classes can a single .NET DLL contain?
Many.
50. Name some of the Microsoft Application Blocks. Have you used any? Which ones?
Examples:Exception Management
Logging
Data Access
User Interface
Caching
Application Block for .NET
Asynchronous Invocation
Application Block for .NET Configuration Management
Application Block for .NET (there are others)
We use Exception and Data Access

51. 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.

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

53. 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.

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

55. 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.

Additional:
- Briefly explain how code behind works and contrast that using the inline
style.
- What are HTML controls, Web controls, and server controls.
- Briefly explain how the server control validation controls work.
- Briefly explain what user controls are and what server controls are and
the differences between the two.
- Briefly explain how server form post-back works (perhaps ask about view state as well).
- Can the action attribute of a server-side tag be set to a value and if not how can you possibly pass data from a form page to a subsequent page. (Extra credit: Have you heard of comdna. :-)
- Briefly describe the role of global.asax.
- How would ASP and ASP.NET apps run at the same time on the same server?
- What are good ADO.NET object(s) to replace the ADO Recordset object.