您如何从具有重载构造方法的抽象类派生

Question

I have an Abstract Class having 2 overloaded constructors. I want to require all derived classes to implement both constructors as both variations support some of the virtual methods provided by Class A that would be very beneficial of all the derived classes. My model resembles the following:

public abstract class A
{
    protected int _x {get;set;}
    protected int _y {get;set;}
    protected string _z {get;set;}

    public A(int x, int y)
    {
       _x = x;
       _y = y;
    }
    public A(int x, int y, string z)
    {
       _x = x;
       _y = y;
       _z = z;
    }
}

I know I can declare the 1st constructor like this:

public class B : A { B(int x, int y) : base (x , y) {}

}

But how would one go about declaring the 2nd constructor of the Abstract class in the derived class?

Answer 1

You don't inherit constructors at all. You declare whichever constructors you want, and make sure that each one chains appropriately, either to a base class constructor, or to another constructor in the same class.

So for example, you could have:

public class B : A
{
    public B(int x, int y) : base(x , y) {}    
    public B(int x, int y, string z) : base(x, y, z) {}

    public B() : base(0, 0, "Hello!") {}

    public B(int x) : this(x, 10, "Chained to B") {}
}