Say any 3 key features of WCF?

<h4>
   1. Unified Programming Model.
   2. Service Oriented Architecture.
   3. Cross-Vendor interoperability.

</h4>

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What are the layers in the 3-tier application ?

There three layers in 3-tier application are:
1. Presentation (UI)
2. Business ( code Logic )
3. Data (storage)

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When is the ViewState available during the page life cycle ?

Viewstate is available after the Init() and before the Page_Load() or OnLoad().

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Do you know any of 3rd party Logging Component ?

log4net is a open source tool to help the programmer output log statements to a variety of output targets.

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What is a lapsed listener problem in .NET?

It is the one of the causes for the leaks in .net. It occurs when a subscriber signs up for a publisher's event, but fails to unsubscribe. The problem is it doesnt get Garbage collected as it still holds reference.

Best solution is to give a UnSubscribe() method.

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What are the valid datasources of a datagrid?

Valid data sources for the DataGrid are:

•DataTable
•DataView
•DataSet
•DataViewManager

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Can the data in the repeater control be edited?

No.

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