Can we call a base.base constructor in C#?

Question

Given two abstract classes, the parent having a constructor

public abstract class MyAbstractBaseClass
{
  public MyAbstractBaseClass(string arg){}
}


public abstract class MyAbstractSubClass:MyAbstractBaseClass
{
  // Properties and Methods
}

, can we instantiate a concrete subclass?

public class MyConcreteSubClass:MyAbstractSubClass
{
  public MyConcreteSubClass() // Call MyAbstractBaseClass("aStrign")
  {
  }

One could create an Init() function in the base class, but this would be rather a workaround than a solution.

score 3 · Accepted Answer · edited May 23 '17 at 11:57

Constructors are not inherited.

base for MyConcreteSubClass is MyAbstractSubClass, and MyAbstractSubClass does not have a constructor that accepts a string.

If you want the constructor "inherited", you have to redeclare it:

public abstract class MyAbstractSubClass : MyAbstractBaseClass
{
  public MyAbstractSubClass (string arg) : base(arg) {}
  // Properties and Methods
}

Then you can call it with base("hello") from MyConcreteSubClass.

score 0 · Answer 2 · answered Aug 13 '14 at 06:34

0

The constructor in the sub class also needs a body:

public class MyConcreteSubClass : MyAbstractBaseClass
{
    public MyConcreteSubClass() : base("hello")
    {
    }
}

answered Aug 13 '14 at 06:34

Oliver Hanappi

12,046
7
51
68

score 0 · Answer 3 · answered Aug 13 '14 at 06:34

0

public class MyConcreteSubClass : MyAbstractBaseClass
{
  public MyConcreteSubClass():base("hello") {}   
}

You have to inherit from your BaseClass to compile it :)

answered Aug 13 '14 at 06:34

S.L.

1,056
7
15

Can we call a base.base constructor in C#?

3 Answers3