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Understanding and Implementing Factory Pattern in C#

by Rahul Rajat Singh

In this article, we will try to understand what is Factory Pattern, what are the benefits of this pattern and how we can implement this pattern using C#.

On the fly Code Generation with Evolutility

by Evoluteur

A generic Web User Interface for CRUD applications generating all screens at run-time based on external metadata. It comes with sample applications for address book, memo pad, to do list, restaurants list, wine cellar, and database structure documentation that are easily customizable.

Fluent Interface Pattern in C# - With Inheritance Problem

by Mark Pelf

Tutorial article on Fluent Interface Pattern in C#

MatchKit Library

by fabio bussu

MatchKit is a .NET Library that provides a set of classes to build patterns to match simple and complex strings

Latest Articles

How to Use Polly In C#: Easily Handle Faults And Retries

by Dev Leader

Learn how to use Polly in C# to handle faults and retries with ease! Check out three code examples showcasing different use cases of Polly in C#!

Command Pattern in C# – What You Need to Implement It

by Dev Leader

Learn what the Command Pattern in C# is and the design principles it follows. Understand the pros and cons!

Dynamic Strategy State Pattern

by Stridemann

Example of use of this pattern in game development

Traversal State Pattern

by Stridemann

A Pattern for Identifying Processed Entities During Iteration Without Additional Collections

All Articles

Patterns

Understanding and Implementing Factory Pattern in C#

9 Feb 2015 by Rahul Rajat Singh

In this article, we will try to understand what is Factory Pattern, what are the benefits of this pattern and how we can implement this pattern using C#.

On the fly Code Generation with Evolutility

11 Jun 2010 by Evoluteur

A generic Web User Interface for CRUD applications generating all screens at run-time based on external metadata. It comes with sample applications for address book, memo pad, to do list, restaurants list, wine cellar, and database structure documentation that are easily customizable.

Fluent Interface Pattern in C# - With Inheritance Problem

5 Mar 2022 by Mark Pelf

Tutorial article on Fluent Interface Pattern in C#

MatchKit Library

21 Apr 2014 by fabio bussu

MatchKit is a .NET Library that provides a set of classes to build patterns to match simple and complex strings

An Absolute Beginner's Tutorial on Understanding and Implementing Singleton Pattern in C#

20 Jan 2016 by Rahul Rajat Singh

This article is yet another explanation and implementation of the singleton pattern.

WCF by Example - Chapter VII - Decoupling of WCF Services from the ViewModel

11 Oct 2011 by Enrique Albert

Baseline WCF Distribution Layer - Decoupling of WCF Services and ViewModels.

Much Ado About NULL

26 Feb 2015 by Giovanni Scerra

Patterns to prevent null reference exceptions

The Rule of Transparency

2 May 2015 by Giovanni Scerra

An introduction to transparency in software design, with particular focus on OO languages

SOLID Principles: The Liskov Principle -> What, Why and How

11 Nov 2018 by Christian Vos

SOLID principles: The Liskov Principle, a simple example in C#

Building an application using design patterns and principles in C# Part II

23 Apr 2013 by Jon Woo

I am writing this article to demonstrate how to build an application from scratch using SOLID principles and common design patterns

Logging Proxy in C#

9 May 2022 by Mark Pelf

In this article, we build a practical reusable Logging Proxy in C#

Simple Singleton Pattern in C#

9 Jul 2011 by Paulo Zemek

The easiest singleton pattern is the one you used to the lock object itself.Creating any variable as static readonly and initializing it directly (or via a static constructor) will already make it singleton.Also, considering that "lock" clears all the caches, you don't need to declare the...

Service Locator Pattern in C#

13 Jul 2022 by Mark Pelf

Beginner’s tutorial on Service Locator Pattern with examples

Observer Pattern in C#

11 Sep 2022 by Mark Pelf

Tutorial article on Observer pattern in C#

multi-threading

Visitor Pattern in C# - 5 Versions

28 Feb 2022 by Mark Pelf

Tutorial article describing Visitor Pattern in C#

Wrapper Pattern for Silverlight and WPF

14 Feb 2010 by Nicolas Dorier

A design pattern to easily bind or animate properties that do not exist on an element, and which works in both Silverlight and WPF

Add Aspects to Object Using Dynamic Decorator

29 Sep 2010 by Gary H Guo

Discuss how to add aspects to object at runtime and enhance them using Dynamic Decorator

Reusing ADO.NET Code using Template Design Pattern

16 Jul 2015 by Shivprasad koirala

In this article, we will demonstrate Template Pattern reusing ADO.NET.

A generic equality comparer library which will work across types

14 Nov 2013 by shijo joseph

An extension methods library which could do the equality comparison operations easily

A Simplified Parameterized Query Class in Classic ASP

19 Mar 2014 by David Cantrell

In which a class that wraps an ADO Connection object and makes it more developer-friendly is discussed.

Violating Liskov Substitution Principle (LSP)

6 Sep 2013 by Ryszard Dżegan

How to not damage yourself when using inheritance.

State Machine - State Pattern vs. Classic Approach

5 Aug 2014 by Chris875

State pattern and procedural solution illustrated

Domain Context Pattern

16 Sep 2014 by Gediminas Geigalas

In your domain model, you often need to pass the same repetitive information to your domain entities or value objects. This article suggests a solution that I call "Domain Context".

Good Practices for Starting with Containers

2 Jun 2020 by Kevin Mack

Few ideas for strengthening micro-services architectures

Software Developers are lazy but smart, that's why we RAD: The PHP.Show Concept

8 Oct 2015 by Anele 'Mashy' Mbanga

A look at a flexible Java MySQL CRUD PHP script generator

Extending Object Behavior with the Decorator Pattern in C#

5 Apr 2023 by Kenji Elzerman

C# decorator pattern allows adding behavior to objects at runtime. In this tutorial, I show you how to implement the decorator pattern with C# in a minimal API.

Using Rails Service Objects to Keep Code Clean

29 Aug 2022 by Aleksandr Ulanov

What are Service Objects and how you can use them to make your app cleaner and keep it maintainable

design-patterns

How to create only one instance per class

14 Mar 2011 by Tarun.K.S

That's possible using a Singleton Class.Check this link : http://csharpindepth.com/Articles/General/Singleton.aspx[^]The author provided a nice and elegant explanation to implement it, its thread safe too. Hope it helped! :)

How to create only one instance per class

14 Mar 2011 by Sandeep Mewara

Okay. Did you come across class the design pattern called Singleton class yet?Here:http://msdn.microsoft.com/en-us/library/ff650316.aspx[^]http://msdn.microsoft.com/en-us/library/ee817670.aspx[^]

How to create only one instance per class

14 Mar 2011 by Manfred Rudolf Bihy

Please see my solution to this question here: how to open only one instance of class not more than that ?[^]. Eventhough it's for a windows form class the same principles apply for other classes too.As Sandeep already pointed out there is a design pattern called Singleton, which will solve...

How to create only one instance per class

15 Mar 2011 by Espen Harlinn

Take a look at the Lazy Class[^] - it provides an implementation of the singleton pattern.Your implementation contains a small bug - you need to make getInstance() static too. The will enable you to get the single instance of OnlyOne using OnlyOne obj = OnlyOne::getInstance();private...

About Design Patterns Singleton and Factory

14 Mar 2011 by TweakBird

Hi Go through this design_patterns[^], You will good idea. Very good one for beginners.[Update]Similar discussion on stackoverflow.com,When to use the singleton[^]When to use factory methods?[^]Some other articles,Pattern Singleton[^]Pattern Factory[^]

About Design Patterns Singleton and Factory

15 Mar 2011 by Espen Harlinn

Here is a Lazy :)System.Lazy[^]Implements the singleton pattern in .Net ...Best regardsEspen Harlinn

MVC vs 3-tier Architecture

31 Jul 2011 by Keith Barrow

No they aren't the same, though they do have similarities. Formally, in a 3-tier system, there is no communication between the data tier and the ui/presentation tier, both must communicate with the logic/model tier/ The topology is layered:Presentation / GUI------------------Logic /...

SystemFramework library

24 Nov 2011 by Scanix

SystemFramework defines interfaces, classes, and types to support a native runtime system with its own garbage collector, delegates, etc. The design of SystemFramework classes is similar to those of the .NET Framework.

Looking for Best Practice on Extending Class Structure

6 Dec 2011 by Sergey Alexandrovich Kryukov

The solution cannot be universal because everything depends on the nature of changing requirements. Resorting to extensions as opposed to modification cannot really help.I can see only one way: to change approach from hard-coded structures to stored meta-data and knowledge engineering, in...

Dependency Injected Singletons… What?

2 Aug 2013 by Dev Leader

About dependency injected singletons

MVP Pattern

11 Oct 2013 by ASP.NET Community

MVP (Model View Presenter) FrameworkThe MVP pattern is an Architecture Pattern used to build ASP.net applications. It refers to splitting up the

DESIGN PATTERNS - API

29 Dec 2013 by pasztorpisti

You can create a good interface that is a common denominator of many other APIs only if already know the other APIs and the intersection of their functionalities. Often the good solution is not a bloated wanna-be-smart and generalized interface but one that contains only a few simple-stupid...

DESIGN PATTERNS - API

29 Dec 2013 by Sergey Alexandrovich Kryukov

Please see my comment to the question. I strongly believe that the project should not be driven by design patterns, but your project should drive the choice of design patterns. Sorry if this advice is not specific enough, but it is no less specific than your description of the goals of your...

How do I return objects of different types from the same function

11 May 2015 by Sascha Lefèvre

You can't have methods in the same class that only differ by their return type.I can think of two ways for code-reuse here, both requiring making Execute(..) a generic method.1) If you can replace Func1 and Func2 by a generic Func :public T Execute(object parameters){ ...

How to identify the software design problem ?

6 Nov 2015 by Sergey Alexandrovich Kryukov

There are absolutely no any cookbook recipes to be used to identify design problems. Perhaps except one: take the whole problem to be solved from scratch and try to sketch some best designs you can invent. If your plan looks much better than existing design, that existing design flawed. But be...

C# - Value Object Pattern, Data Transfer Object Pattern

7 Feb 2023 by Mark Pelf

Beginner’s tutorial on VO and DTO Patterns with examples

About Design Patterns Singleton and Factory

14 Mar 2011 by Sergey Alexandrovich Kryukov

The Question in not completely incorrect, but can be greatly improved. You should have re-formulated it:"How to use Wikipedia, Google, CodeProject and StackOverflow.com?"If you asked and got good Answers, the Questions like your original one would not be needed!—SA

What architecture and design pattern to use for a asp.net web application

31 May 2011 by Sergey Alexandrovich Kryukov

In addition to what Abhinav says: it totally depends on your functional requirements.No design pattern is good by itself.Three-tiers architecture is not considered a design pattern or architectural pattern, as it's more of application architecture, and design patterns are more...

Strategy Pattern VS Static Class

7 Oct 2011 by Sander Rossel

With the strategy pattern it is possible to change or extend the behaviour of a Class.This sounds a bit abstract, but let's look at an example.public interface IMathOperation{ double PerformOperation(double A, double B);}class DoMath{ private double _A; private...

Simple Singleton Pattern in C#

7 Nov 2011 by Henry.Ayoola

Jon Skeet has written an article giving six singleton implementations in C#. The simplest only works in .NET 4:public sealed class Singleton{ private static readonly Lazy lazy = new Lazy(() => new Singleton()); public static Singleton Instance {...

Decorator Design Pattern

18 Jan 2012 by Sergey Alexandrovich Kryukov

Wikipedia is on a blackout for a really good reason at this moment, in response to SOPA and PIPA bills. Please see:http://en.wikipedia.org/wiki/Main_Page[^], http://en.wikipedia.org/wiki/Wikipedia:SOPA_initiative/Learn_more[^].It will be available soon. Hope it will be fine in future as...

visitor pattern- challenge question for mediocres for practice! answer and win a chance to get job in biggest software houses in world!

20 Dec 2012 by Adam R Harris

The winner of this will also get 1 billion dollhairs !!!!!

Design Patterns

11 Oct 2013 by ASP.NET Community

Design PatternsDesign patterns are recognized solutions to common problems defined originally by the Gang of Four programmers. Design patterns are

What Pattern am I looking for?

20 Oct 2013 by Sergey Alexandrovich Kryukov

I think, in your speculations on the classes, interfaces and methods you already limited yourself to some unreasonably rigid set of possible type designs. You need to take a wider look.I can see two approaches.First one would be this: you have one and only one color class. This and only...

PHP Adapter Pattern in Action

2 Feb 2015 by Chris_Yu

Why and When to Use the Adapter Pattern in PHP Development

How Can I Get The Matched String In Pattern In Vb.Net

22 Dec 2015 by Richard Deeming

Your parameters are the wrong way round - the first parameter is the string to test, and the second parameter is the regular expression to use:Regex.IsMatch(myString, ".* My name is XYZ")To retrieve the details of the match, use the Match method[^], which returns a Match object[^]....

regular-expression

How do I creat the following pattern in C?

4 Aug 2016 by Patrice T

This is HomeWork, so only advices.The pattern is:Pascal's triangle - Wikipedia, the free encyclopedia[^]-try to solve the problem as 2 problems: - solve the computing of each rows values. - Solve the presentationyou need to remember the previous row to compute the next one.Nota:...

When Creating An Interface and/or Abstract Class is an Overkill

13 Oct 2016 by Rahul Rajat Singh

This is a small tip containing my thoughts on why we should not blindly create interfaces and/or abstract class for each and every class in our application.

About Design Patterns Singleton and Factory

14 Mar 2011 by Albin Abel

E$w@r's link is a good one. In a nutshell Singletons are generally used prevent repeated load of a heavy resource in memory. Say class A has a big common dataset which is reusable. If many other objects access various instance of this object then it is a wastage of memory, because the same type...

RegEx pattern needed

17 Oct 2011 by NewPast

Dim pattern="http.*\.flv"Dim pattern2="^http.*\.flv$"'^ means at the 1st of the line; $ means at the end of the line

regular-expression

Model view controller to write easily maintainable and extendable application

23 Jan 2012 by malakar.anil

This article explains how to write easily maintainable and extendable application using MVC

C# pattern - is it same as in image?

13 May 2012 by Clifford Nelson

Acutally made error in putting the "-" inside the Math.Pow(-(x1 - Math.PI), 2), and the approach is not the best. I would also not use the Pow for square because of perfomance, and would use the Exp function:var VALUE = - Math.Cos(x1) * Math.Cos(x2) * Math.Exp(-(x1 -nu) *(x1 - Math.PI) -(x2...

How to compare image with a slightly different another image(rotation, brightness, angle) in c#

28 Jun 2012 by email2gtc

I am creating an application to recognize books by its spine. What I want to do is take picture of a book spine and match it with a database of books.I was hoping to use pattern matching and template matching for this. First i was hoping to search book by template matching using templats of...

image-processing

How to create Login page in "asp. mvc patter"

1 Aug 2012 by Christian Graus

If you're not using the MVC framework, then how are you using MVC ? You can write a login page in ASP.NET without using MVC, but you can't easily use the MVC pattern in ASP.NET if you don't use the framework, the restraints of the ASP.NET framework make it harder to impliment an arbitrary design...

Design Architecture of UML Editor

9 Dec 2012 by Sergey Alexandrovich Kryukov

You need to look at Data Contract. Please see:http://msdn.microsoft.com/en-us/library/ms733127.aspx[^].Please see my past answer where I explain it:How can I utilize XML File streamwriter and reader in my form application?[^],Creating property files...[^].—SA

Design Architecture of UML Editor

12 Dec 2012 by Sergey Alexandrovich Kryukov

Please see my comments on persistence. If should be either Data Contract or something like that. It should be agnostic to UML. As soon as your persistence start depending on UML definitions or anything of application field, consider all your development dead. And it should be no XAML, because...

Design Architecture of UML Editor

12 Dec 2012 by Sergey Alexandrovich Kryukov

OK, I'll show some very rough sketch of UML hierarchy. Very preliminary, pseudo-code, and only for Class Diagram and top level. Perhaps you well see that you might under-estimate the task.Let's start with abstract top level of hierarchy: abstract class Element { // Name:...

C# Forbidden Signs in Datanamespaces Regex pattern

20 Feb 2013 by Joezer BH

Try this:string regexSearch = new string(Path.GetInvalidFileNameChars()) + new string(Path.GetInvalidPathChars());Regex r = new Regex(string.Format("[{0}]", Regex.Escape(regexSearch)));Cheers, Edo

regular-expression

Singleton Pattern in action?

22 Mar 2013 by OriginalGriff

Google is your friend: Be nice and visit him often. He can answer questions a lot more quickly than posting them here...A very quick search using part of your question as the search term gave : 1.6 million hits.when to use singleton pattern[^]In future, please try to do at least...

Another Generic State Machine

19 May 2013 by Yossi Yaari

A basic yet generic state machine implementation

Singletons: Why Are They “Bad”?

9 Aug 2013 by Dev Leader

In this post, I’m going to focus on why singletons are “bad”, because for me it means acknowledging one of the two main perspectives–that they are the best thing since cat videos met The Internet or they are the worst thing since Justin Bieber.

Design Pattern for Entity Framework

10 Sep 2013 by TheUltimateDebugger

As far my knowledge so farRepository Pattern With Entity Framework[^]

entity-framework

Class Vs. SingletonClass

25 Sep 2013 by OriginalGriff

The biggest difference (indeed in code terms pretty much the only difference) is that a Singleton class does not have a public constructor: you have to go via the class GetInstance method (or similar) in order to create an instance as the outside world is not allowed to use:MySingletonClass...

Visitor Pattern

14 Jan 2014 by ASP.NET Community

The visitor design pattern enables us to create new operations to be performed on an existing structure. The new operations don’t change the

Iterator Pattern

19 Oct 2013 by ASP.NET Community

The iterator pattern’s role is to provide a way to access aggregate objects sequentially without the knowledge of the structure of the aggregate.

Use of design pattern

12 Dec 2013 by Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ)

I would suggest you to have two Tables.1. Users2. RoleThese tables should have a Relationship through the RoleId. That means RoleId will be ForeignKey in Users Table.For instance...UsersID Name RoleId1 Abc 12 Def 2RoleID Name1 ...

How do I return objects of different types from the same function

11 May 2015 by BillWoodruff

Here's an example of a static generic Class that will return instances of new Classes where the internal data type used by the new Class is constrained to be a struct. I believe this example demonstrates the "usual" features of implementing the Factory Class pattern in C#: use of an interface;...

What is singleton and why we have to use

25 Apr 2018 by OriginalGriff

The idea of a singleton is very simple: it's a class with a private constructor, so it cannot be instantiated form outside the class. This means that the class is absolutely in control of how many instances of the class are created, and when they are created. A singleton class creates a single...

What is singleton and why we have to use

25 Apr 2018 by CPallini

I would start form its very Wikipedia page: Singleton pattern - Wikipedia[^].

Regular expression pattern help

31 Aug 2018 by Peter Leow

Try this: ^[0-9]$|^1[0-2]$ for the first one. You should be able to figure out the other one. The 30 Minute Regex Tutorial[^]

Stateful Serverless: Long-Running Workflows with Durable Functions

22 Nov 2019 by Jeremy Likness

Stateful serverless: long running workflows with durable functions

What Are Some Things I Can Do to Improve Application Availability?

12 Mar 2020 by Kevin Mack

What kinds of things should I avoid, or remove from my applications to improve my position moving forward

C#11 - Immutable Object Pattern

6 Feb 2023 by Mark Pelf

Basic tutorial on Immutable Object Pattern along with C# examples

3rd Party API Integration Pattern

14 Nov 2023 by Nish Nishant

System.nullreferenceexception in repository pattern

18 Dec 2023 by M Imran Ansari

As the error message, the issue is in Delete method. The Delete method attempts to remove an entity from the context using LapShopContext.Set().Remove(entity). However, the error you're encountering is a NullReferenceException, which suggests...

entity-framework

Dynamic Strategy State Pattern

11 Dec 2023 by Stridemann

Example of use of this pattern in game development

How to Use Polly In C#: Easily Handle Faults And Retries

12 Mar 2024 by Dev Leader

Learn how to use Polly in C# to handle faults and retries with ease! Check out three code examples showcasing different use cases of Polly in C#!

Communication pattern

7 Feb 2010 by Samer Aburabie

I am not sure if I understood you well, but you mixed things up here, you are talking about a communication protocol like TCP/IP or UDP and in the same time you want to implement it with a design pattern !?!! I think your worries should be bigger than that.

c# singleton : design question

21 Feb 2011 by jim lahey

I would assume that because the new members you propose to add are members of a singleton object, that they will in fact also be singletons by means of association. in a traditional singleton pattern you access the only instance via the static .Instance member which can have a double locking...

Please help with pattern matching

14 Mar 2011 by OriginalGriff

You are looking for a regular expression. This is what Expresso came up with:' Imports System.Text.RegularExpressions' Regular expression built for Visual Basic on: Mon, Mar 14, 2011, 01:42:46 PM' Using Expresso Version: 3.0.3634, http://www.ultrapico.com'' A description of the...

how to know which software design pattern to choose ?

27 Mar 2011 by #realJSOP

Pick the one that gets the job done, or don't pick one at all. I've never consciously made a decision to use a specific "design pattern". I do what makes sense for the project, and get on with my life. I usually split the interface as much as possible from everything else, and go with it. If...

Help me in Singleton Pattern

29 May 2011 by Sandeep Mewara

Here:MSDN: Singleton Implementation[^]MSDN: Exploring Singleton Design Pattern[^]Singleton design pattern: Thread-safe Singleton[^]Implementing the Singleton Pattern in C#[^]This answer and others to the same question would also help: About Design Patterns Singleton and Factory[^]

What architecture and design pattern to use for a asp.net web application

31 May 2011 by BobJanova

In addition to the excellent links already posted:Architecture is a somewhat nebulous concept, but relates to high level design decisions, and things which become expensive to change later on. The '3 tier' architecture is traditional for web applications and it works well (though one might...

MVC vs 3-tier Architecture

31 Jul 2011 by Uday P.Singh

Hi guys!!I have read a lot about both, but still confused. Does MVC and 3-Tier both are same? If yes then why these two exists, just for different naming? If no then what are the basic and main differences in these two?Please Reply(No extra links Please as I have already googled it but...

Case Studies for Design Pattern

10 Sep 2011 by Dennis Th

Hidid you try gang of fours' homepage ?they have a lot of tutorialsDennis

Case Studies for Design Pattern

10 Sep 2011 by Pravin Patil, Mumbai

Check out : 1. Non Software Examples and Case Studies[^]2. From Experts - Design Patterns Explained with Practical Examples[^]Hope this helps.All the best.

Strategy Pattern VS Static Class

7 Oct 2011 by EgyptianRobot

need someone professional help me get the difference beteenfirst : static class SimpleMathOperations { public static double add(double a, double b) { return a + b; } public static double subtract(double a, double b) { return a - b; } public...

Dynamics CRM 5.0 - Integration with ASP.NET 4.0

15 Oct 2011 by Espen Harlinn

Take a look at these pages Microsoft Dynamics CRM SDK[^] - A web service, as in Web Service Walkthroughs[^] is probably your best choice - think in terms of operations, and only expose what is strictly required."Moreover,will there be any need of load balancing (web farm ) for 6000 to 7000...

Looking for Best Practice on Extending Class Structure

6 Dec 2011 by kkadir

Hello,It is a common problem that during an ongoing project requirements do change frequently. Functional changes can be handled using -for instance- the decorator pattern and so on. But a serious problem is that when the static structure of any entity changes. You have to do relentless...

Singleton pattern without lazy loading

24 Feb 2012 by Sander Rossel

Actually I don't think this should be a problem. If you are using a singleton pattern you are probably calling a shared method that initializes your object. Even though the object is created on a certain thread this should not prevent it from being accessed from others (unless it's some UI...

3-Tier ASP.Net Application Using Design Pattern

9 Apr 2012 by Rahul Rajat Singh

3 tier application development can be understood by following examples.YaBlogEngine - A Tiny Blog Engine written in ASP.NET/C#[^]YaMessaging - A simple e-mail like messaging application[^]and use of design patterns depends more on the business logic need and overall architecture....

Implementing IComparable and IEquatable safely and fully

22 Jun 2012 by A. Ganzer

Using snippets to create a full and correct implementation of complex interfaces

How to compare image with a slightly different another image(rotation, brightness, angle) in c#

28 Jun 2012 by krumia

You have done well to use histograms to identify similar images. You will have to use pattern recognition[^] to do the rest.Try separate algorithms for cropping, rotating and scaling the image. For example when a photo of a book spine is provided,1. You first rotate it such that the spine...

image-processing