Dernière version du 7 juin 2020 à 17:07

Definition

Convert the interface of a class into another interface that clients expect.
The Adapter pattern lets classes work together that could not otherwise because of incompatible interfaces.

Match otherwise incompatible interfaces

Exemple

Rectangle.cs

public interface IRectangle
{
    int GetArea();
}

public class Rectangle : IRectangle
{
    private readonly int width;
    private readonly int lenght;

    public Rectangle(int width, int lenght)
    {
        this.lenght = lenght;
        this.width = width;
    }

    public int GetArea() => width * lenght;
}

Disk

public interface IDisk
{
    double ComputeArea();
}

public class Disk : IDisk
{
    private readonly int radius;

    public Disk(int radius)
    {
        this.radius = radius;
    }

    public double ComputeArea() => 2 * Math.PI * radius;
}

DiskToRectangleAdapter.cs

public class DiskToRectangleAdapter : IRectangle
{
    private readonly IDisk disk;

    public DiskToRectangleAdapter(IDisk disk)
    {
        this.disk = disk;
    }

    public int GetArea() => (int)disk.ComputeArea();
}

var rectangles = new List<IRectangle>();
IRectangle rectangle = new Rectangle(40, 30);
rectangles.Add(rectangle);

IDisk disk = new Disk(100);
IRectangle adaptedDisk = new DiskToRectangleAdapter(disk);
rectangles.Add(adaptedDisk);

DisplayArea(rectangles);

void DisplayArea(IEnumerable<IRectangle> rectangles)
{
    foreach (var rectangle in rectangles)
    {
        Console.WriteLine(rectangle.GetArea());
    }
}