Convert Interface to Abstract Class refactoring

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

Consider the following example:

            
  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
    }
  }

        

            
  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
    }
  }

        

Convert an interface into an abstract class

Select an interface in one of the following ways:
- In the editor, set the caret at the name of an interface.
- Select an interface in the Solution Explorer.
- Select an interface in the File Structure window.
- Select an interface in the Class View.
- Select an interface in the Object Browser.
- Select an interface in the type dependency diagram.
Do one of the following:
- Press Control+Shift+R and then choose Convert Interface to Abstract Class.
- Right-click and choose Refactor | Convert Interface to Abstract Class from the context menu.
- Choose ReSharper | Refactor | Convert | Method to Indexer… from the main menu.
If no conflicts are found, ReSharper performs the refactoring immediately. Otherwise, it prompts you to resolve conflicts.

This feature is supported in the following languages and technologies:

The instructions and examples given here address the use of the feature in C#. For details specific to other languages, see corresponding topics in the ReSharper by language section.

Last modified: 08 March 2021