Observable class to notify event which property changes.

Observable.cs

public class Observable : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    public void Set<T>(ref T target, T value, [CallerMemberName] string propertyName = null)
    {
        if (target.Equals(value)) return;

        target = value;

        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}