What is XHTML? Are ASP.NET Pages compliant with XHTML?
In simple words, XHTML is a stricter and cleaner version of HTML. XHTML stands for EXtensible Hypertext Markup Language and is a W3C Recommendation.
Yes, ASP.NET 2.0 Pages are XHTML compliant. However the freedom has been given to the user to include the appropriate document type declaration.
Can I deploy the application without deploying the source code on the server?
Yes. You can obfuscate your code by using a new precompilation process called ‘precompilation for deployment’. You can use the aspnet_compiler.exe to precompile a site. This process builds each page in your web application into a single application DLL and some placeholder files. These files can then be deployed to the server.
You can also accomplish the same task using Visual Studio 2005 by using the Build->Publish menu.
Does ViewState affect performance? What is the ideal size of a ViewState? How can you compress a viewstate?
Viewstate stores the state of controls in HTML hidden fields. At times, this information can grow in size. This does affect the overall responsiveness of the page, thereby affecting performance. The ideal size of a viewstate should be not more than 25-30% of the page size.
How can you detect if a viewstate has been tampered?
By setting the EnableViewStateMac to true in the @Page directive. This attribute checks the encoded and encrypted viewstate for tampering
Can I use different programming languages in the same application?
Yes. Each page can be written with a different programming language in the same application. You can create a few pages in C# and a few in VB.NET.
Can the App_Code folder contain source code files in different programming languages?
No. All source code files kept in the root App_Code folder must be in the same programming language.
Update: However, you can create two subfolders inside the App_Code and then add both C# and VB.NET in the respective subfolders. You also have to add configuration settings in the web.config for this to work.
How do you secure your connection string information?
By using the Protected Configuration feature.
How do you secure your configuration files to be accessed remotely by unauthorized users?
ASP.NET configures IIS to deny access to any user that requests access to the Machine.config or Web.config files.
How can I configure ASP.NET applications that are running on a remote machine?
You can use the Web Site Administration Tool to configure remote websites.
How many web.config files can I have in an application?
You can keep multiple web.config files in an application. You can place a Web.config file inside a folder or wherever you need (apart from some exceptions) to override the configuration settings that are inherited from a configuration file located at a higher level in the hierarchy.
I have created a configuration setting in my web.config and have kept it at the root level. How do I prevent it from being overridden by another web.config that appears lower in the hierarchy?
By setting the element's Override attribute to false.
What is the difference between Response.Write and Response.Output.Write?
As quoted by Scott Hanselman, the short answer is that the latter gives you String.Format-style output and the former doesn't.
What is Cross Page Posting? How is it done?
By default, ASP.NET submits a form to the same page. In cross-page posting, the form is submitted to a different page. This is done by setting the ‘PostBackUrl’ property of the button(that causes postback) to the desired page. In the code-behind of the page to which the form has been posted, use the ‘FindControl’method of the ‘PreviousPage’ property to reference the data of the control in the first page.
Can you change a Master Page dynamically at runtime? How?
Yes. To change a master page, set the MasterPageFile property to point to the .master page during the PreInit page event.
How do you apply Themes to an entire application?
By specifying the theme in the web.config file.
How do you exclude an ASP.NET page from using Themes?
To remove themes from your page, use the EnableTheming attribute of the Page directive.
Your client complains that he has a large form that collects user input. He wants to break the form into sections, keeping the information in the forms related. Which control will you use?
The ASP.NET Wizard Control.
Do webservices support data reader?
No. However it does support a dataset.
What is use of the AutoEventWireup attribute in the Page directive ?
The AutoEventWireUp is a boolean attribute that allows automatic wireup of page events when this attribute is set to true on the page. It is set to True by default for a C# web form whereas it is set as False for VB.NET forms. Pages developed with Visual Studio .NET have this attribute set to false, and page events are individually tied to handlers.
What happens when you change the web.config file at run time?
ASP.NET invalidates the existing cache and assembles a new cache. Then ASP.NET automatically restarts the application to apply the changes.
Can you programmatically access IIS configuration settings?
Yes. You can use ADSI, WMI, or COM interfaces to configure IIS programmatically.
What is globalization?
Globalization is the process of customizing applications that support multiple cultures and regions.
What is localization?
Localization is the process of customizing applications that support a given culture and regions.
What is MIME?
The definition of MIME or Multipurpose Internet Mail Extensions as stated in MSDN is “MIME is a standard that can be used to include content of various types in a single message. MIME extends the Simple Mail Transfer Protocol (SMTP) format of mail messages to include multiple content, both textual and non-textual. Parts of the message may be images, audio, or text in different character sets. The MIME standard derives from RFCs such as 2821 and 2822”.
What is an application server?
As defined in Wikipedia, an application server is a software engine that delivers applications to client computers or devices. The application server runs your server code. Some well known application servers are IIS (Microsoft), WebLogic Server (BEA), JBoss (Red Hat), WebSphere (IBM).
Compare C# and VB.NET
What is a base class and derived class?
A class is a template for creating an object. The class from which other classes derive fundamental functionality is called a base class. For e.g. If Class Y derives from Class X, then Class X is a base class.
The class which derives functionality from a base class is called a derived class. If Class Y derives from Class X, then Class Y is a derived class.
What is an extender class?
An extender class allows you to extend the functionality of an existing control. It is used in Windows forms applications to add properties to controls.
What is inheritance?
Inheritance represents the relationship between two classes where one type derives functionality from a second type and then extends it by adding new methods, properties, events, fields and constants.
C# support two types of inheritance:
· Implementation inheritance
· Interface inheritance
What is implementation and interface inheritance?
When a class (type) is derived from another class(type) such that it inherits all the members of the base type it is Implementation Inheritance.
When a type (class or a struct) inherits only the signatures of the functions from another type it is Interface Inheritance.
In general Classes can be derived from another class, hence support Implementation inheritance. At the same time Classes can also be derived from one or more interfaces. Hence they support Interface inheritance.
What is inheritance hierarchy?
The class which derives functionality from a base class is called a derived class. A derived class can also act as a base class for another class. Thus it is possible to create a tree-like structure that illustrates the relationship between all related classes. This structure is known as the inheritance hierarchy.
How do you prevent a class from being inherited?
In VB.NET you use the NotInheritable modifier to prevent programmers from using the class as a base class. In C#, use the sealed keyword.
Explain Different Types of Constructors in C#?
There are four different types of constructors you can write in a class -
1. Default Constructor
2. Parameterized Constructor
3. Copy Constructor
4. Static Constructor
Define Overriding?
Overriding is a concept where a method in a derived class uses the same name, return type, and arguments as a method in its base class. In other words, if the derived class contains its own implementation of the method rather than using the method in the base class, the process is called overriding.
Can you use multiple inheritance in .NET?
.NET supports only single inheritance. However the purpose is accomplished using multiple interfaces.
Why don’t we have multiple inheritance in .NET?
There are several reasons for this. In simple words, the efforts are more, benefits are less. Different languages have different implementation requirements of multiple inheritance. So in order to implement multiple inheritance, we need to study the implementation aspects of all the languages that are CLR compliant and then implement a common methodology of implementing it. This is too much of efforts. Moreover multiple interface inheritance very much covers the benefits that multiple inheritance has.
What is an Interface?
An interface is a standard or contract that contains only the signatures of methods or events. The implementation is done in the class that inherits from this interface. Interfaces are primarily used to set a common standard or contract.
What are events and delegates?
An event is a message sent by a control to notify the occurrence of an action. However it is not known which object receives the event. For this reason, .NET provides a special type called Delegate which acts as an intermediary between the sender object and receiver object.
What is business logic?
It is the functionality which handles the exchange of information between database and a user interface.
What is a component?
Component is a group of logically related classes and methods. A component is a class that implements the IComponent interface or uses a class that implements IComponent interface.
What is a control?
A control is a component that provides user-interface (UI) capabilities.
What are design patterns?
Design patterns are common solutions to common design problems.
What is a connection pool?
A connection pool is a ‘collection of connections’ which are shared between the clients requesting one. Once the connection is closed, it returns back to the pool. This allows the connections to be reused.
What is a flat file?
A flat file is the name given to text, which can be read or written only sequentially.
What are functional and non-functional requirements?
Functional requirements defines the behavior of a system whereas non-functional requirements specify how the system should behave; in other words they specify the quality requirements and judge the behavior of a system.
E.g.
Functional - Display a chart which shows the maximum number of products sold in a region.
Non-functional – The data presented in the chart must be updated every 5 minutes.
What is the global assembly cache (GAC)?
GAC is a machine-wide cache of assemblies that allows .NET applications to share libraries. GAC solves some of the problems associated with dll’s (DLL Hell).
What is a stack? What is a heap? Give the differences between the two?
Stack is a place in the memory where value types are stored. Heap is a place in the memory where the reference types are stored.
What is instrumentation?
It is the ability to monitor an application so that information about the application’s progress, performance and status can be captured and reported.
What is code review?
The process of examining the source code generally through a peer, to verify it against best practices.
What is logging?
Logging is the process of persisting information about the status of an application.
What are mock-ups?
Mock-ups are a set of designs in the form of screens, diagrams, snapshots etc., that helps verify the design and acquire feedback about the application’s requirements and use cases, at an early stage of the design process.
What is a Form?
A form is a representation of any window displayed in your application. Form can be used to create standard, borderless, floating, modal windows.
What is a multiple-document interface(MDI)?
A user interface container that enables a user to work with more than one document at a time. E.g. Microsoft Excel.
What is a single-document interface (SDI) ?
A user interface that is created to manage graphical user interfaces and controls into single windows. E.g. Microsoft Word
What is BLOB ?
A BLOB (binary large object) is a large item such as an image or an exe represented in binary form.
What is ClickOnce?
ClickOnce is a new deployment technology that allows you to create and publish self-updating applications that can be installed and run with minimal user interaction.
What is object role modeling (ORM) ?
It is a logical model for designing and querying database models. There are various ORM tools in the market like CaseTalk, Microsoft Visio for Enterprise Architects, Infagon etc.
What is a private assembly?
A private assembly is local to the installation directory of an application and is used only by that application.
What is a shared assembly?
A shared assembly is kept in the global assembly cache (GAC) and can be used by one or more applications on a machine.
What is the difference between user and custom controls?
User controls are easier to create whereas custom controls require extra effort.
User controls are used when the layout is static whereas custom controls are used in dynamic layouts.
A user control cannot be added to the toolbox whereas a custom control can be.
A separate copy of a user control is required in every application that uses it whereas since custom controls are stored in the GAC, only a single copy can be used by all applications.
Where do custom controls reside?
In the global assembly cache (GAC).
What is a third-party control ?
A third-party control is one that is not created by the owners of a project. They are usually used to save time and resources and reuse the functionality developed by others (third-party).
What is a binary formatter?
Binary formatter is used to serialize and deserialize an object in binary format.
What is Boxing/Unboxing?
Boxing is used to convert value types to object.
E.g. int x = 1;
object obj = x ;
Unboxing is used to convert the object back to the value type.
E.g. int y = (int)obj;
Boxing/unboxing is quiet an expensive operation.
What is a COM Callable Wrapper (CCW)?
CCW is a wrapper created by the common language runtime(CLR) that enables COM components to access .NET objects.
What is a Runtime Callable Wrapper (RCW)?
RCW is a wrapper created by the common language runtime(CLR) to enable .NET components to call COM components.
What is a digital signature?
A digital signature is an electronic signature used to verify/gurantee the identity of the individual who is sending the message.
