Design Patterns in C#

Overview

This project demonstrates the implementation of key design patterns in C#, focusing on a notification system. The system allows users to send notifications via Email or SMS, utilizing various design patterns to ensure maintainability and scalability.

Implemented Design Patterns

1. Singleton Pattern → Ensures a single instance of the UserList class, managing a shared user list.
2. Factory Pattern → Dynamically creates notification senders (Email or SMS).
3. Facade Pattern → Provides a simple interface (NotificationFacade) to handle complex notification logic.
4. Observer Pattern → Notifies multiple users when a message is sent.

Project Structure

📂 DesignPatterns-main
 ├── 📄 Program.cs          # Main entry point of the application
 ├── 📄 Singleton.cs        # Singleton pattern implementation
 ├── 📄 FactoryDesign.cs    # Factory pattern implementation
 ├── 📄 FacadeDesign.cs     # Facade pattern implementation
 ├── 📄 ObserverDesign.cs   # Observer pattern implementation
 ├── 📄 NotificationApp.csproj # Project file
 ├── 📄 NotifucationApp.sln # Solution file

Installation & Usage

Prerequisites

• .NET SDK installed (version 6 or later)

Steps to Run

1. Clone the repository:

   git clone https://github.com/your-username/DesignPatterns.git
   cd DesignPatterns-main

2. Build the project:

   dotnet build

3. Run the project:

   dotnet run

4. Enter the notification mode (email or sms), then provide a subject and body.

How It Works

1. User Input: The program asks the user to select a notification mode (email or sms).
2. Factory Pattern: The system dynamically creates the required sender (Email/SMS) using FactoryofNotificationSendType.
3. Facade Pattern: NotificationFacade simplifies the process of fetching user data (via Singleton) and sending notifications.
4. Observer Pattern: The system notifies all subscribed users when a message is sent.

Example Output

Enter Notification sending mode (email/sms): email
Enter Subject: Meeting Reminder
Enter Body: Meeting at 5 PM

Selected Mode is Email and is sent to: Neeraj Yadav - Meeting Reminder - Meeting at 5 PM
Selected Mode is Email and is sent to: Ajeet Kumar - Meeting Reminder - Meeting at 5 PM
...

Contributing

Feel free to fork this repository and submit pull requests with improvements.

License

This project is licensed under the MIT License. See LICENSE for details.

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