Hands-On Design Patterns with C# and .NET Core

InventoryCommandFactory

The InventoryCommandFactory class is an implementation of the Factory pattern using .Net classes, which requires both readings of, and writing to, the collection of books:

public class InventoryCommandFactory : IInventoryCommandFactory{    private readonly IUserInterface _userInterface;    private readonly IInventoryContext _context;     public InventoryCommandFactory(IUserInterface userInterface, IInventoryContext context)    {        _userInterface = userInterface;        _context = context;     }    public InventoryCommand GetCommand(string input)    {        switch (input.ToLower())        {            case "q":            case "quit":                return new QuitCommand(_userInterface);            case "a":            case "addinventory":                return new AddInventoryCommand(_userInterface, _context);            case "g": case "getinventory": ...