What are Design Patterns?

Question

Hi Please expain What all are the advantages of Design Patterns and frequently used design patterns

Ananth G · Answer

Tutorial: Common Design Patterns in C# 4.0 Design Patterns provide standardized and efficient solutions to software design and programming problems that are re-usable in your code. Software Architects and developers use them to build high quality robust applications. However you have to take care to select the right pattern for the right problem. If you need to modify the initial pattern too much this may indicate that it is not adapted to your needs and may in the worst case lead to unmaintainable complex and inefficient code. The opposite of what you intend when using Design Patterns !! You may also create your own custom Design Patterns. Whenever you come up with a certain solution that is reusable in a vast majority of your projects you may decide to abstract a design pattern out of it. Then you may create your own library of patterns and share them within your whole company thus creating standards and ameliorating maintainability. I am going to show you how to use the well known Gang of Four (GoF) Design Patterns in C# 4.0 code. Those patterns will work well in any project that uses C# but especially in WPF WCF WinForms ASP.NET projects. The GoF Design Patterns are divided into 3 categories : Creational Patterns Structural Patterns and Behavioral Patterns. I am going to explain each GoF Design Pattern in detail and will show you examples of how to write good C# 4.0 code that implement those patterns. Creational Patterns Abstract Factory Pattern: Create instances of classes belonging to different families Builder Pattern: Separate representation and object construction Factory Method Pattern: Create instances of derived classes Prototype Pattern: Clone or copy initialized instances Singleton Pattern: Class with only one single possible instance Structural Patterns Adapter Pattern: Match interfaces of classes with different interfaces Bridge Pattern:: Separate implementation and object interfaces Composite: Simple and composite objects tree Decorator: Dynamically add responsibilities to objects Facade: Class that represents subclasses and subsystems Flyweight: Minimize memory usage by sharing as much data as possible with similar objects Proxy: Object that represents another object Behavioral Patterns Chain of Responsibility: Pass requests between command and processing objects within a chain of objects Command: Encapsulate a method call as an object containing all necessary information Interpreter: Include language elements and evaluate sentences in a given language Iterator: Give sequential access to elements in a collection Mediator: Encapsulates and simplifies communication between objects Memento: Undo modifications and restore an object to its initial state Observer: Notify dependent objects of state changes State: Change object behavior depending on its state Strategy: Encapsulate algorithms within a class and make them interchangeable Template Method: Define an algorithm skeleton and delegate algorithm steps to subclasses so that they may be overridden Visitor: Add new operations to classes without modifying them There are also many other types of patterns such as: Parallel Patterns SOA Patterns Enterprise Architecture Patterns etc… So if you work in the respective area don’t hesitate to look up patterns that may help you to be more efficient and build better applications. Reference: https://csharpdesignpatterns.codeplex.com/

Salman · Answer

Hi. Design Patterns are  popular solutions for common design problems . Basically there are 3 categories of Design Pattern. 1/Creational 2/Structural 3/Behavioural and each category contains number of Design patterns. Without writing the same code again and again we can use Design pattern. Basically dp are used in almost all projects and it will be better to use and the performance issue also decrease. Let me give an example of Observer DP. i have and company and when i will launch a new product then by Observer DP i will send the mail to each client bcoz they are observing me. Please read it DP and i can assure you that you are really inspired to implement in your project. Please follow this article and also so many articles are present http://www.c-sharpcorner.com/article/design-patterns-in-c-sharp/ let me know if you need any kind of help. thanks.

Ravi Patel · Answer

Hi check this https://csharpdesignpatterns.codeplex.com/ https://www.youtube.com/watch?v=YDobmucohqk

Dhananjay Kumar · Answer

Design Patterns https://msdn.microsoft.com/en-us/library/orm-9780596527730-01.aspx

Bikesh Srivastava · Answer

According my theory Design pattern is just a way to write code in c#.Everyone is using design patter in your application by default but they don't know what is this. So its just way what scenario you are following to write code in c# using OOPS concept.