Question

I have a WPF UserControl which implements ISlider with some CustomEvent (see previous episode Why I cannot compile a Custom Event declared in a Class Interface in C# ).

Now my problem is the code below doesn’t want to compile :

        ISlider ISlider;
        ISlider = slider as ISlider;
        if (ISlider != null)
        {
            ISlider.CustomEvent += new CustomEvent(OnCustomEvent);
        }
        else
        {
            this.slider.ValueChanged += new RoutedPropertyChangedEventHandler<double>(this.slider_ValueChanged);
        } 

because UserControls don’t have a ValueChanged Event like WPF standard controls do.

So the line:

this.slider.ValueChanged += new RoutedPropertyChangedEventHandler<double>(this.slider_ValueChanged);

doesn’t compile.

So am I obliged to artificially create a ValueChanged event in my ISlider interface when I have no use of it, just to satisfy the compiler ?

Answer 1

So am I obliged to artificially create a ValueChanged event … just to satisfy the compiler ?

Yes.