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Command System Design Pattern

The Command Design Pattern is a behavioral pattern used to encapsulate a request as an object. It separates the responsibility of issuing commands from the responsibility of executing them. This pattern involves four main components:

1. ICommand: An interface that declares a method for executing the command.
2. CommandImplementation: Implements the Command interface and defines the binding between a receiver object and an action.
3. Client: Creates a CommandImplementation object and sets its receiver.
4. Invoker/Sender: Asks the command to execute the request.
5. Receiver: Knows how to perform the operation to satisfy a request.

This pattern is useful for implementing undo/redo functionality, queuing operations, or logging changes. It promotes loose coupling between the sender and the receiver of the request.

Project Overview

The project showcases how to apply the Command Pattern to three common file operations:

• Deleting a file
• Uploading a file
• Downloading a file

Files

• ICommand.cs: Defines the command interface with an 'Execute' method.
• FileOperationInvoker.cs: Manages command execution by holding and invoking commands.
• DeleteFileCommand.cs: Implements a command to delete a file.
• UploadFileCommand.cs: Implements a command to upload a file.
• DownloadFileCommand.cs: Implements a command to download a file.
• Test Cases

Class Diagram

The following class diagram shows how the command pattern is implemented in this example of doing basic file operations.