WpfExtensions.Binding 0.1.0

WpfExtensions.Binding

This module is designed to solve the problem of property update dependency, which is often encountered in development: the value of a property is calculated from multiple other property, then when these dependent properties changed, the resultant property also needs to notify the UI to update. For example: RectArea = Width * Height, all three properties in this formula need to be bound to the UI, and the display of the RectArea will be automatically refreshed when Width and Height are changed.

To achieve this effect, the traditional implementation is as follows, and it's not hard to find: it's quite a pain to write, and each dependent property has to add a line of code to notify the result property to refresh.

// View Model
public double Width {
    get => field;
    set {
        if (SetProperty(ref field, value)) {
            RaisePropertyChanged(nameof(RectArea));
        }
    }
}

public double Height {
    get => field;
    set {
        if (SetProperty(ref field, value)) {
            RaisePropertyChanged(nameof(RectArea));
        }
    }
}

public double RectArea => Width * Height;

So after using WpfExtensions.Binding, can it be shorter?

// View Model is derived from WpfExtensions.Binding.BindableBase.
public double Width {
    get => field;
    set => SetProperty(ref field, value);
}

public double Height {
    get => field;
    set => SetProperty(ref field, value);
}

public double RectArea => Computed(() => Width * Height);

Perhaps this example is too simple. If the same property affects multiple results, then multiple result properties have to be raised in that property. Such an intricate update dependency is not easy to maintain.