Convert Interface to Abstract Class refactoring

Last modified: 23 September 2024

This refactoring converts interfaces into abstract classes thus helping you quickly change hierarchical dependency among a set of classes and interfaces.

tip

The reverse functionality is available with the Convert Abstract Class to Interface refactoring refactoring.

Consider the following example:

Before refactoring

interface Shape
{
  double Area { get; }
  void Draw();
}
 
class Circle : Shape
{
  private readonly int radius;
  public double Area => Math.PI * Math.Pow(radius, 2);
 
  public void Draw()
  {
    //do something
  }
}

After refactoring

abstract class Shape
{
  public abstract double Area { get; }
  public abstract void Draw();
}
 
class Circle : Shape
{
  private readonly int radius;
  public override double Area => Math.PI * Math.Pow(radius, 2);
 
  public override void Draw()
  {
    //do something
  }
}

tip

After performing this refactoring, you may want to bring some members from derived classes to the newly created abstract class. You can do it with the Pull Members Up refactoring.

Convert an interface into an abstract class

  1. Select an interface in one of the following ways:

    • In the editor, place the caret at the name of an interface.

    • Select an interface in the Solution Explorer.

    • Select an interface in the Structure window window.

  2. Do one of the following:

    • Press and then choose Convert Interface to Abstract Class.

    • Choose Refactor | Convert Interface to Abstract Class from the main menu.

  3. If no conflicts are found, JetBrains Rider performs the refactoring immediately. Otherwise, it prompts you to resolve conflicts.

    tip

    Right after the refactoring has been completed, all changes that it makes anywhere, including other files, are registered as a single operation. So you can use the Undo action to roll back all these changes with a single keystroke.

See also

Procedures