[Solved] What is the right way to call function from a class that does not implement the function class? [closed]

by


There are two easy ways to achieve this:

  • with an instance of Parent passed to Child
  • use inheritance and a virtual method in Parent but do not override it in Child

The first one can be achieved like this:

class Parent {
    Child c = new Child(this);

    public void Func(){ ... }
}

public class Child() 
{
    private Parent _parent;

    public Child(Parent parent)
    {
        _parent = parent;
    }

    public void SomeRandomMethod() 
    {
        if (_parent != null)
            _parent.Func();
    }
}

The second option would look like this:

class Parent {
    Child c = new Child();

    public virtual void Func(){ ... }
}

class Child : Parent
{
    public void SomeRandomMethod()
    {
        Func(); //because the child hasn't overridden this the method in the parent will get called
    }    
}

Edit:

Based on your updated requirements, here is a (very!) rough semi-pseudocode example using a delegate that is injected into the Logic class. There are a number of ways this code could be structured. I’ve also assumed that you’ll need to pass multiple parameters to the Draw() function so I’ve encapsulated that in an object. I also returned a bool from that method – if no return is necessary then change the Func<DrawingParameters, bool> to Action<DrawingParameters>.

public class Ui
{

    public Ui()
    {
        var l = new Logic() { DrawingMethod = Draw } ;
    }

    public bool Draw(DrawingParameters dp)
    {
        //do your drawing
        return true;
    }
}

public class Logic
{
    public Func<DrawingParameters, bool> DrawingMethod { private get; set; }

    public void DoCalculationsAndDraw()
    {
        var drawingParameters = new DrawingParameters();

        //do your calculations, set values in drawingParameters...

        DrawingMethod?.Invoke(drawingParameters);
    }
}

public class DrawingParameters
{
    public Point StartPoint { get; set; }
    public Point EndPoint { get; set; }

    //etc.....
}

3

solved What is the right way to call function from a class that does not implement the function class? [closed]