public class Father

    {

        protected bool focus = false;

        public void SetFocus(bool fo)

        {

            this.focus = fo;

        }

        private Child _child;



        public Child Child

        {

            get

            {

                if (_child == null)

                {

                    return new Child();

                }

                return _child;

            }

            set

            {

                if (_child == null)

                {

                    _child = new Child();

                }

                _child = value;

            }

        }



    }

    public class Child : Father

    {

        public bool GetFoucValue()

        {

            return base.focus;

        }

    }





   private void button1_Click(object sender, EventArgs e)

        {

            //Child child = new Child();

            //child.SetFocus(true);

            //bool oo = child.GetFoucValue();

            Father father = new Father();

            father.SetFocus(true);

            bool err = father.Child.GetFoucValue();

        }