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Bridge Pattern

Bridge Pattern 


Gamma Categorization: Structural Design Pattern
Summary: A mechanism that decouples an interface (hierarchy) from an implementation (hierarchy).

Sample Code

Problem: We want to be able to implement the photo storage mechanism.

Code

public interface IStorage
{
    void SaveFile(byte[] bytes);
}

public class InternalStorage : IStorage
{
    public void SaveFile(byte[] bytes)
    {
        System.Console.WriteLine("File sent to disk.");
    }
}

    public class CloudStorage : IStorage
{
    public void SaveFile(byte[] bytes)
    {
        System.Console.WriteLine("File sent to server.");
    }
}

public class DigitalCamera
{
    private IStorage storage;

    public DigitalCamera(IStorage storage)
    {
        this.storage = storage;
    }

    public void TakePhoto()
    {
        // Simulation of taking a photo from the digital image sensor
        byte[] photo = new byte[1024];
        System.Console.WriteLine("Photo retrieved.");

        // Saving photo
        storage.SaveFile(photo);
    }

}

Usage

var camera = new DigitalCamera(new CloudStorage());
camera.TakePhoto();

Output

Photo retrieved.
File sent to server.

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