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Behavioral Design Pattern in C#

The Behavioral Design Patterns in C# focuses on improving communication between objects. In C#, these patterns play an important role in facilitating clear and effective communication between objects, making the systems easier to understand and manage. They focus on the responsibilities of objects and how they communicate, which helps reduce tight coupling. In this article, I will give a brief introduction to Behavioral Design Patterns in C#. Please read our previous article discussing the Structural Design Patterns in C# with examples. As part of this article, we will discuss the following three things.

1. What is the Behavioral Design Pattern?
2. When to use the Behavioral Design Pattern?
3. Examples of Behavioral Design Patterns
4. Benefits of Behavioral Design Patterns in C#

What is the Behavioral Design Pattern in C#?

Behavioral Design Patterns deal with the communication or interaction between Classes and Objects. This ensures that the communication is carried out effectively while keeping the coupling loose. The primary goal of these patterns is to enhance the communication between objects, making it more flexible and efficient.

So, the behavioral design pattern explains how objects interact with each other. It describes how different objects and classes send messages to each other to make things happen and how the steps of a task are divided among different objects.

When to use Behavioral Design Patterns in C#?

In real-time applications, sometimes we want to change the behavior of a class, and again, we don’t want it to affect other classes of the project. For example, we have an Invoice class that currently applies taxes as 18%. Tomorrow, if we want to add another extra tax. That means we are changing the behavior of a class. The Behavioral Design Pattern comes into the picture to solve such behavioral issues. Implementing Behavioral Design Patterns in C# helps to manage and optimize the interactions between objects and behaviors in an application:

• Flexibility in Interaction: These patterns provide greater flexibility in deciding how objects interact with each other.
• Ease of Maintenance: Encapsulating behavior in objects or classes that can be easily modified independently enhances maintainability.
• Enhanced Control Flow: They can improve the control flow between objects and manage complex conditions more effectively.

Examples of Behavioral Design Patterns in C#:

The following design patterns belong to the Behavioral Design Pattern category.

Chain of Responsibility Pattern:

The Chain of Responsibility Design Pattern allows an object to send commands without knowing which object will receive and handle them. Requests are passed along a chain of potential handlers until one of them deals with the request.

Command Pattern:

The Command Design Pattern turns a request into a stand-alone object containing all the requested information. This transformation allows command execution to be parameterized with different requests, queues, or log operations and supports undoable operations. For example, GUI buttons. Each button has a command associated with it. When the button is pressed, its command is executed. 

Interpreter Pattern:

The Interpreter Design Pattern is used to design a component that interprets programs written in a dedicated language. It is used in C# when a system requires an automated and flexible way to include scripting capabilities.

Iterator Pattern:

The Iterator Design Pattern provides a way to access the elements of an aggregate object sequentially without exposing its underlying representation. In C#, it’s integral to the collection framework and is used extensively for safely navigating collections.

Mediator Pattern:

The Mediator Design Pattern reduces the dependencies between objects by making them communicate indirectly through a specially designed mediator object. This pattern is used in C# to facilitate better handling of complex communications that are hard to manage through direct comms. For example, chat rooms where users send messages to the mediator (chat room) rather than sending them directly to other users. The mediator then forwards the message to all other users.

Memento Pattern:

The Memento Design Pattern captures and externalizes an object’s internal state so that it can be restored later, all without violating encapsulation. This is useful in C# for implementing undo capabilities in software.

Observer Pattern:

The Observer Design Pattern allows several observer objects to see an event and respond to it. It is commonly used in C# to implement distributed event-handling systems. For example, an event-driven system like a stock market feed, where stocks update subscribed investors whenever their prices change.

State Pattern:

The State Design Pattern allows an object to alter its behavior when its internal state changes. This pattern is used in C# to manage the state in complex control flows. For example, a context-aware chatbot that changes its behavior based on the user’s status (e.g., new user, returning user, premium user). Each state would encapsulate the behavior and responses relevant to that particular user state.

Strategy Pattern:

The Strategy Design Pattern defines a family of algorithms, encapsulates each one, and makes them interchangeable. Strategy lets the algorithm vary independently from the clients that use it. In C#, it encapsulates algorithms as objects and makes them interchangeable. For example, a payment gateway system that supports multiple payment methods, like credit cards, PayPal, or cryptocurrency, can use the strategy pattern to encapsulate each payment method behind a common interface, making adding or removing payment methods easy.

Template Method Pattern:

The Template Method Design Pattern defines the skeleton of an algorithm in the superclass but lets subclasses override specific steps of the algorithm without changing its structure. This is used in C# to define a general workflow in a base class and allow subclasses to implement specific behavior.

Visitor Pattern:

The Visitor Design Pattern lets you define a new operation without changing the classes of the elements on which it operates. It is useful in C#, especially for operations applied to a group of objects with differing classes.

Benefits of Behavioral Design Patterns

The following are the Benefits of Behavioral Design Patterns in C#:

• Improved Handling of Interactions: By focusing on effective communication and responsibility delegation, these patterns improve the handling of complex interactions.
• Increased Modularity: Encouraging fine-grained and decoupled object interactions leads to more modular code.
• Dynamic Control: Many behavioral patterns, such as State and Strategy, allow for changes in software’s behavior in runtime, making it more dynamic and responsive.

In the next article, I will discuss the Iterator Design Pattern in C# with Examples. Here, in this article, I try to give a brief introduction to Behavioral Design Patterns. I hope you understand the need and use of the Behavioral Design Pattern in C#.