C# + ReSharper = Awesome: Tip #4 – Convert Abstract Class to Interface

This is the fourth in a series of quick how-to articles on ReSharper.

Tip #4 – Convert Abstract Class to Interface

Use: This is used when the class(es) that will be inheriting from a base class also need to inherit from another base class. Derived types can inherit from only one base class but can implement multiple interfaces.

Before

   1:      public abstract class Book

   2:      {

   3:          public abstract string Title { get; set; }

   4:   

   5:          public abstract string Year { get; set; }

   6:   

   7:          public abstract string Author { get; set; }

   8:   

   9:          public abstract void Lend();

  10:   

  11:          public abstract void AddToInventory();

  12:      }

Right-click the class

After

   1:      public interface Book

   2:      {

   3:          string Title { get; set; }

   4:          string Year { get; set; }

   5:          string Author { get; set; }

   6:          void Lend();

   7:          void AddToInventory();

   8:      }

Note: Notice that this refactoring does not change the name of the type. At this point, there will be a squiggly line under the interface’s name, Book. Placing the cursor on Book and pressing <Alt+Enter> will prompt ReSharper to rename it to IBook.

Happy coding!