Extract Superclass refactoring
ReSharper_ExtractSuperclass
This refactoring allows you to extract certain members from a selected class into a new base class. The original class will extend the created base class.
If the current type already implements any interfaces, these interfaces can also be extracted into the new base class.
If you want to create an abstract class, mark at least one of the extracted method abstract.
In the example below, we extract an abstract class Shape from the existing class Circle:
| Before refactoring | After refactoring |
|---|---|
public class Circle : IDrawable
{
public Point Center { get; private set; }
public Color MyColor { get; private set; }
public int Radius { get; private set; }
public void Draw()
{
// draw...
}
}
public interface IDrawable
{
void Draw();
} | public abstract class Shape : IDrawable
{
public Color MyColor { get; private set; }
public abstract void Draw();
}
public class Circle : Shape
{
public Point Center { get; private set; }
public int Radius { get; private set; }
public override void Draw()
{
// draw...
}
}
public interface IDrawable
{
void Draw();
} |
To extract a base class
- Select a class in one of the following ways:
- In the editor, set the caret at the name of a class.
- Select a class in the Solution Explorer.
- Select a class in the File Structure window.
- Select a class in the Class View.
- Select a class in the Object Browser.
- Select a class in the type dependency diagram.
- Do one of the following:
- Press Ctrl+Shift+R and then choose Extract Superclass
- Right-click and choose Refactor | Extract Superclass in the context menu.
- Choose in the main menu.
- Specify a name for the base class and where it should be placed - in a new file or in the same file as the original type.
- Select members that you want to transfer to the new base class. The list of members can contain:
- Members of the current type
- Interfaces that the selected type currently implements
- To make/keep individual members abstract, tick the check box in the Make Abstract column next to them. If there is at least one member marked abstract, the base class will be created abstract too.
- To quickly select all public members, click All Public.
- If you select members that reference other members, there will be undefined symbols in the extracted class. Click Dependent to resolve the conflict by selecting all members that depend on the currently selected members.
- To apply the refactoring, click Next.
- 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:
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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.