Interfaces

Describes signatures

  • Properties
  • Methods

Interface Example - IAdjustSpeed

public interface IAdjustSpeed
{
    void Accelerate(double rate, TimeSpan duration);
    void Decelerate(double rate, TimeSpan duration);
    double CurrentSpeed { get; }
}

Interface Example - IAdjustSpeed

public class Treadmill : IAdjustSpeed
{
    public void Accelerate(double rate, TimeSpan duration)
    {
        // Implementation body
    }

    public void Decelerate(double rate, TimeSpan duration)
    {
        // Implementation body
    }

    public double CurrentSpeed { get; private set; }
}

Interface Example - IAdjustSpeed

public class Car : IAdjustSpeed
{
    public void Accelerate(double rate, TimeSpan duration)
    {
        // Implementation body
    }

    public void Decelerate(double rate, TimeSpan duration)
    {
        // Implementation body
    }

    public double CurrentSpeed { get; set; }
}

Interface Example - IAdjustSpeed

public class Elevator : IAdjustSpeed
{
    public void Accelerate(double rate, TimeSpan duration)
    {
        // Implementation body
    }

    public void Decelerate(double rate, TimeSpan duration)
    {
        // Implementation body
    }

    public double CurrentSpeed { get; set; }
}

Interface Example - IAdjustSpeed

public class ControlPanel
{
    private IAdjustSpeed _ControlledItem;
    public ControlPanel(IAdjustSpeed obj)
    {
        _ControlledItem = obj;
    }

    public void HandleKeypress(char key)
    {
        switch(key)
        {
            case "w":
                _ControlledItem.Accelerate(boostRate, new TimeSpan(0, 0, 5));
                break;
            // ...
        }
    }
}

Interface Example - ILocatable IPingable

Adapted from an old text-based Star Trek game

public interface ILocatable
{
    Location QuadrantPosition { get; }
    Location SectorPosition { get; }
    Quadrant Quadrant { get; }
    Sector Sector { get; }
}

public interface IPingable
{
    string Ping();
}

Interface Implementation Example

public class Star : AbstractLocatable
{
    public string ping() {
        return " * ";
    }
}

public class Space : IPingable
{
    public string ping() {
        return "  ";
    }
}

The End

> **Dependency Inversion Principle** > > - Depend on abstractions, not on concretions TODO: - Interfaces in .Net Core