← Modification précédente Modification suivante →

Version du 6 juin 2020 à 22:33

Description

Decouple an abstraction from its implementation so that the two can vary independently.

Exemple

The client can change the *Logger classes he wants to use without having to modify the UserService.

ILogger.cs

public interface ILogger
{
    void WriteLine(string text);
}

ConsoleLogger

public class ConsoleLogger : ILogger
{
    public void WriteLine(string text)
    {
        Console.WriteLine(text);
    }
}

IUserService.cs

public interface IUserService
{
    void ChangePassword(int userId, string newPassword);
}

UserService.cs

public class UserService : IUserService
{
    private ILogger logger;

    public UserService(ILogger logger)
    {
        this.logger = logger;
    }

    public void ChangePassword(int userId, string newPassword)
    {
        logger.WriteLine($"Password has been change for user {userId}.");
    }
}

IUserService userService = new UserService(new ConsoleLogger());
userService.ChangePassword(1, "0000");

@@ Ligne 5 : / Ligne 5 : @@
 = Exemple =
-* The {{boxx|*Logger}} classes can be modified without modifying the {{boxx|UserService}} as long as it follows the {{boxx|ILogger}} contract.
+* The client can change the {{boxx|*Logger}} classes he wants to use without having to modify the {{boxx|UserService}}.
 <filebox fn='ILogger.cs'>
 public interface ILogger