Question

During object construction I should initialize several parameters. As an example

Vehicle (color)
     I
Car (transmission type, air conditioning (boolean))
     I
Cabriolet (roof (boolean))

I also need ability to Reload all parameters at any time (because my parameters are actually changable). I was thinking to create virtual ReloadParameters() method for each class which will call super and load this class parameters.

The problem is that I also need to load all parameters during construction and I don’t want to call virtual method from constructor because this is bad practice.

What would you suggest?

Answer 1

To avoid calling a virtual method in the constructor, make a non-virtual private method, and call that from both the constructor and the virtual method:

class Vehicle
{
    public Vehicle()
    {
        LoadVehicleParameters();
    }
    virtual void ReloadParameters()
    {
        LoadVehicleParameters();
    }
    private void LoadVehicleParameters();
    {
         //logic here.
    }
}
class Car : Vehicle
{
    public Car() // call to base constructor is implicit
    {
        LoadCarParameters();
    }
    virtual void ReloadParameters()
    {
        base.ReloadParameters();
        LoadCarParameters();
    }
    private void LoadCarParameters();
    {
         //logic here.
    }
}

If your base class has no parameterless constructor, or if it has more than one constructor, you’ll need to specify which base constructor to call, of course, like this:

public Car(int i) : base(i)
//...