Question

Looking at some c# code from open and closed source project i see that private, and sometimes public methods are designed to recive parameters and not directly access the instance variable to extract the parameter they need

  class A
  {
    private B b;

    public void Methode1()
    {            
        Methode2(b.SomeProperty);
    }                

    private void Methode2(string param)
    {         
    }
  }

Is this considered as a good practice, or it’s just a programming way?

Answer 1

Yes, its normal. Consider also moving Methode2 to class B (Tell, don’t ask principle):

 class A
  {
    private B b;

    public void Methode1()
    {            
        b.Methode2();
    }
  }

What is bad – passing whole object as parameter for method, when you need only value of it’s property (don’t pass to method more, than it needs for execution):

 class A
  {
    private B b;

    public void Methode1()
    {            
        Methode2(b);
    }                

    private void Methode2(B b)
    {
        // use b.SomeProperty         
    }
  }