JetBrains Rider 2017.2 Help

Generating Type Constructors

Code | Generate | Constructor
Alt+Insert | Constructor

The constructor generation wizard creates a non-default constructor that takes parameters for selected fields, properties and auto-properties.

All generated constructors follow the same pattern where:

  • Each field, property, or auto-property included in the constructor is initialized with a parameter.
  • The name of the parameter is derived from the name of the corresponding field or property.

If there are non-default base type constructors, the required parameters are added to the generated constructor and passed to the base class constructor.

In the example below, this command is used to generate a new Circle constructor that takes two additional parameters to initialize _radius and _center fields.

Before generationAfter generation
internal class Shape { public Shape(Color color) { Color = color; } public Color Color { get; } } class Circle : Shape { int _radius; Point _center; public Circle(Color color) : base(color) { } }
internal class Shape { public Shape(Color color) { Color = color; } public Color Color { get; } } class Circle : Shape { int _radius; Point _center; public Circle(Color color) : base(color) { } public Circle(Color color, int radius, Point center) : base(color) { _radius = radius; _center = center; } }

To generate a constructor

  1. In the editor, set the caret on the type name or within a type at the line where you want to insert a constructor. If the caret is on the type name, generated code will be added in the beginning of the type declaration.
  2. Press Alt+Insert or choose Code | Generate... in the main menu.
  3. In the Generate pop-up menu, select Constructor.
  4. In the Generate dialog that appears, select type members that should be initialized in the new constructor. Optionally, select one or several base class constructors. For every selected base constructor, a new constructor will be generated that will call the base and additionally initialize selected members.
    Generating type constructors with JetBrains Rider

    Optionally, use the following controls in the dialog:

    • Access Rights — allows you to define access rights for the generated constructor.
    • Check parameters for null (appears if the class has fields or properties of nullable types) — if this check box is selected, JetBrains Rider will generate configurable null checks for each nullable parameter, for example: if (param == null) throw new ArgumentNullException(nameof(param));
    • Make parameters optional — if this check box is selected, JetBrains Rider will make all parameters of the generated constructor optional and add default values corresponding to the parameter types.
  5. Click OK to complete the wizard.
Last modified: 17 November 2017

See Also