Question

I am trying to make custom conmtrol in windows phone.
My control has dependency proprty named Val of type int.
I want to add an event which for any change in inthe value of Val.

my code is :

public int Val
        {
            get { return (int)GetValue(ValProperty); }
            set { SetValue(ValProperty,value); }
        }

    public static readonly DependencyProperty ValProperty = DependencyProperty.Register("Val", typeof(int), typeof(CT1), new PropertyMetadata(0, ValPropertyChanged));

    private static void ValPropertyChanged(DependencyObject target, DependencyPropertyChangedEventArgs e)
    {
        ((CT1)target).OnValChanged((int)e.OldValue,(int)e.NewValue);
    }

    protected virtual void OnValChanged(int oldvalue, int newvalue)
    {
        //TODO
    }

I dont know to proceed from here. Help needed.

Answer 1

Got it..
This is how it should be.

protected virtual void OnValChanged(int oldvalue, int newvalue)
        {
            if (ValueChanged != null)
                ValueChanged(this, new ValueChangedEventArgs { OldValue = oldvalue, NewValue = newvalue });
        }


        public delegate void ValueChangedEventHandler(object sender, ValueChangedEventArgs e);

        public event ValueChangedEventHandler ValueChanged;