Fire events selectively in C#

Question

class Child
{ 
    private override void Check_CheckedChanged(object sender, EventArgs e)
    {
        if (Check.Checked)
        {
            this.addName(this.FirstName);
            this.disableControls();
        }

        else
        {
            this.addAddress(this.address);
            //this.activatecontrols();// gives error since it's private method in parent.

        }
    }
}

class Parent
{
    private  void Check_CheckedChanged(object sender, EventArgs e)
    {
        if (Check.Checked)
        {
            this.disablecontrols();
        }

        else
        {
            this.addAddress(this.address);
            this.activatecontrols();
        }
    }

}

I want to fire the the child event if it satisfies if condition. But if can not I need to call the base's else condition as I activatecontrols() is private in Parent. So, how do I call the event?

Answer 1

A very simple solution would be to make the ActivateControls protected virtual on Parent and override it on the child, then you can call base.activatecontrols in the child method if not Check.Checked.

Answer 2

If you need the functionality of ActivateControls in the derived class, you can make it protected in the base class.

Alternately, you could have the Check_CheckedChanged event handler call a virtual method in the base class which can be overridden in the derived class:

// Parent.cs

private void Check_CheckedChanged(object sender, EventArgs e)
{
    OnCheckedChanged();
}

protected virtual void OnCheckedChanged()
{
    if (Check.Checked)
    {
        this.disablecontrols();
    }
    else
    {
        this.addAddress(this.address);
        this.activatecontrols();
    }
}

The logic for Parent does not need to be repeated in Child, so that handler can be simplified:

// Child.cs

protected override void OnCheckedChanged()
{
    if (Check.Checked)
    {
        this.addName(this.FirstName);
    }

    base.OnCheckedChanged();  // Same outcome
}