When not to use Design Patterns

Do not use design patterns in any of the following situations.

• When the software being designed would not change with time.
• When the requirements of the source code of the application are unique.

If any of the above applies in the current software design, there is no need to apply design patterns in the current design and increase unnecessary complexity in the design.

When to use Design Patterns

Design Patterns are particularly useful in one of the following scenarios.

• When the software application would change in due course of time.
• When the application contains source code that involves object creation and event notification.

Benefits of Design Patterns

The following are some of the major advantages of using Design Patterns in software development.

• Flexibility
• Adaptability to change
• Reusability

What are Design Patterns?

A Design Pattern essentially consists of a problem in a software design and a solution to the same. In Design Patterns each pattern is described with its name, the motivation behind the pattern and its applicability.
According to MSDN, "A design pattern is a description of a set of interacting classes that provide a framework for a solution to a generalized problem in a specific context or environment. In other words, a pattern suggests a solution to a particular problem or issue in object-oriented software development.

What is Com Marshler and its importance in .NET ?

Com Marshler is one of useful component of CLR. Its Task is to marshal data between Managed and Unmanaged environment .It helps in representation of data accross diffrenet execution enviroment.It performs the conversion of data format between manage and unmanaged code.By the helps of Com Marshlar CLR allows manage code to interoperate with unmanaged code.

Can you define what is SharePoint and some overview about this ?

SharePoint helps workers for  creating  powerful personalized interfaces only by dragging and drop pre-defined Web Part Components. And these Web Parts components also helps non programmers to get information which care  and customize the appearance of Web pages. To under stand it we take an example  one Web Part might display a user's information another might create a graph showing current employee status  and a third might show a list of Employees Salary. This is also possible that each functions has a link to a video or audio presentation.So now  Developers are unable to  create these Web Part components and make them available to SharePoint users.

What you thing about the WebPortal ?

Web portal is nothing but a page that allows a user to customize his/her homepage. We can use Widgets to create that portal we have only to drag and drop widgets on the page. The user can set his Widgets on any where on the page where he has to get them. Widgets are nothing but a page area that helps particular function to response. Widgets example are address books, contact lists, RSS feeds, clocks, calendars, play lists, stock tickers, weather reports, traffic reports, dictionaries, games and another such beautiful things that we can not imagine. We can also say Web Parts in Share Point Portal. These are one of Ajax-Powered.

Define SMTPclient class in DotNet framework class libarary?

Each classes in dotnet framework inclue some properties,method and events.These properties ,methods and events are member of a class.SMTPclient class mainly concern with sending mail.This class contain the folling member.
Properties:-
Host:-The name or IP address of email server.
Port:-Port that is use when sending mail.
Methods:-
Send:-Enables us to send email synchronously.
SendAsynchronous:-Enables us to send an email asynchronously.
Event:-
SendCompleted:-This event raised when an asynchronous send opertion completes.

What do you mean by three-tier architecture?

The three-tier architecture was comes into existence to improve management of code and contents and to improve the performance of the web based applications.There are mainly three layers in three-tier architecture.the are define as follows
(1)Presentation
(2)Business Logic
(3)Database
(1)First layer Presentation contains mainly the interface code, and this is shown to user. This code could contain any technology that can be used on the client side like HTML, JavaScript or VBScript etc.
(2)Second layer is Business Logic which contains all the code of the server-side .This layer have code to interact with database database and to query, manipulate, pass data to user interface and handle any input from the UI as well.
(3)Third layer Data represents the data store like MS Access, SQL Server, an XML file, an Excel file or even a text file containing data also some addtional database are also added to that layers.

What is the Website Administrative Tool in ASP.NET 2.0 ?

In ASP.NET 2.0, while using Visual Studio 2005 Express Edition or above, the development IDE provides an interface for editing the web.config rather than manually editing the web.config.

In the IDE, click on "Website" and then on "ASP.NET Configuration". This shall open the Website configuration tool. Note that the Web Site Administration Tool is a set of prebuilt ASP.NET 2.0 webpages and resources that are located within the C:\Inetpub\wwwroot\aspnet_webadmin\2_0_40607 directory.

Before in my VB app I would just load the icons from DLL. How can I load the icons provided by .NET dynamically?

By using System.Drawing.SystemIcons class' for example System.Drawing.SystemIcons.Warning produces an Icon with a warning sign in it. 

What are three test cases you should go through in unit testing?

1.Positive test cases (correct data, correct output).
2. Negative test cases (broken or missing data, proper handling).
3. Exception test cases (exceptions are thrown and caught properly).

Using COM components in .NET and How to add a reference to a COM component?

The .NET does not encourage the use of COM component directly inside the managed application! Although, the .NET framework contains utilities that enable COM components to be used inside the .Net applications seamlessly. How it is done? The .NET utilities like TlbImp generates the wrapper .NET assembly for the COM component which provides the same calling interface to the client as exposed by the COM component. Inside the wrapper methods, it calls the actual methods of the COM component and returns the result back to the caller. The generated wrapper .NET assembly is called the ‘Runtime Callable Wrapper’ or RCW.
To use a COM component in your Visual Studio.NET project, you need to add a reference of the COM component in the Reference node of the project node of the solution inside the solution explorer window. The great thing about Visual Studio.Net is that it allows you to add a reference to the COM component in exactly the similar way as you add the reference to the .NET assembly. The Visual Studio.NET automatically creates the runtime callable wrapper assembly for the referenced COM component.
To add a reference to a COM component, right click the ‘Reference’ node under the project node inside the solution explorer and select the ‘Add Reference…’ option. It will show you a user interface screen where you browse for the target COM component. When you have selected the component, press the ‘Select’ button and then press OK. This will add a new reference node in the Reference sub tree of the project. By selecting the added reference node, you can edit its properties from the properties window.
Note: The process of importing a COM component into .NET is called ‘COM interoperability with .NET’

What are XML Doc comments (comments start with three slashes ///)?

The XML Doc comments are special kind of comments that can be recognized by Document utility to automatically generate the documentation of your methods, types and regions.

How true it is that .NET and Java programs are quite in-efficient when compared to C++?

The startup of managed .NET and Java programs is definitely slower than the traditional C++ programs as it involves the hosting of CLR into managed application process in .NET and starting the JVM in a new process in case of Java. The execution also is a bit slower during the initial period of program execution as the intermediate code is translated to the machine code on the fly at runtime. But as the program runs various parts repeatedly, the execution gets pace too. Since, the CLR and JVM optimizes the code more efficiently than the static C++ compilers, the execution speed of the program may actually be faster after sometime of the program startup when most of the code is translated. Hence, in the longer run, the .Net and Java based programs should not be in-efficient when compared to C++. We used ‘should’ here as the actual performance depends on the particular implementation and implementation strategy.

What are the shortcomings of MS.NET platform?

The foremost short coming of .NET platform is that it is still the propriety of Microsoft. It is more coupled with the Microsoft Windows operating system and is implemented only on Microsoft Windows successfully. MS.NET desktop applications can run only on Microsoft Windows, Web based applications and web services can only be deployed on Microsoft Internet Information Server (IIS). Since, dot net framework contains a lot of utilities, components, and framework class libraries, the size of downloadable framework is quite large (25MB compared to 5MB size of JVM). Not all types of applications can be written in .NET managed applications, for example, you can’t write CLR or Operating System in your managed applications. The managed .Net applications are somewhat slower to start and run than the traditional Win32 applications. The compiled code of .Net managed applications is easier to de-compile back to the source code.

Why should one use MS.NET for software development?

Well, most of the software development all over the world is done on and for Microsoft Windows Operating System. Dot Net is now the standard software development environment for the Microsoft Windows operating system. It dramatically simplifies the development of windows, web based, data access applications, components, controls and web services. Dot net comes with amazing features like XML configuration, reflection, and attributes to ease the overall software development life cycle. Finally, the dot net is supported by the Microsoft Visual Studio Integrated Development Environment; the best IDE available for any software development environment. Visual Studio .NET (VS.NET) supports all the areas of software development from project creation to debugging and installation.

What does one need to build or execute .NET applications?

To execute a standalone .NET application (Windows or Console application), one needs to first compile all its constituent assemblies and modules including the executable assembly. Once, the constituent assemblies are compiled, one needs to make sure that the target system contains the .NET framework. The application can now be executed by running its executable assembly (the .exe file). The executable assembly (.exe) is a Win32 executable that hosts the .Net CLR (Common Language Runtime), which exists as a COM component, in its process space and initializes it. Once the CLR is hosted and initialized, the starting point of the .NET executable assembly is passed to the hosted CLR which starts the execution of the program by translating and executing the parts of the program code.

What is the difference between an executable assembly and a class library?

An executable assembly exists as the .exe file while a class library exists as the .dll file. Executable assembly represent executable applications having some entry (e.g., Main() method in C#). A class library, on the other hand, contains components and libraries to be used inside various applications. A Class library can not be executed and thus it does not have any entry point.

What are the differences between a .NET Assembly, a Windows DLL and a COM Component?

A Windows DLL contains library code to be used by any program running on Windows. A DLL may contain either structured or object oriented libraries.

COM (Component Object Model) is the component model based on the object oriented design, which means that the components represented by the COM component exists in the form of classes and objects implementing a standard specification defined by COM. COM components can be used by any program running on Windows Operating System; be it is written with VB, C++, Java or even some .NET compliant language like C# and VB.NET.

Dot NET assembly is the component standard specified by the .NET. Hence, dot net assemblies are understandable to only Microsoft.NET and can be used only in .NET managed applications.