Creating a bindable Point in C# WPF

Question

I know multiple inheritence is out, but is there a way to create a wrapper for System.Windows.Point that can inherit from it but still implement bindable dependency properties?<

Answer 1

1. Write a wrapper class for point which implements the INotifyPropertyChanged interface

   public class BindingPoint : INotifyPropertyChanged
   {
       private Point point;
   
       public BindingPoint(double x, double y)
       {
           point = new Point(x, y);
       }
   
       public double X
       {
           get { return point.X; }
           set
           {
               point.X = value;
               OnPropertyChanged();
               OnPropertyChanged("Point");
           }
       }
   
       public double Y
       {
           get { return point.Y; }
           set
           {
               point.Y = value;
               OnPropertyChanged();
               OnPropertyChanged("Point");
           }
       }
   
       public Point Point
       {
           get { return point; }
       }
   
       public event PropertyChangedEventHandler PropertyChanged;
   
       [NotifyPropertyChangedInvocator]
       protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
       {
           var handler = PropertyChanged;
           if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
       }
   }
   

2. Bind startpoint / endPoint X and Y properties for example to a line instance

   Line line = new Line();
   BindingPoint startPoint = new BindingPoint(0,0);
   BindingPoint endPoint = new BindingPoint(0,0);
   
   var b = new Binding("X")
   {
       Source = startPoint,
       Mode = BindingMode.TwoWay
   };
   line.SetBinding(Line.X1Property, b);
   
   b = new Binding("Y")
   {
       Source = startPoint,
       Mode = BindingMode.TwoWay
   };
   line.SetBinding(Line.Y1Property, b);
   
   b = new Binding("X")
   {
       Source = endPoint,
       Mode = BindingMode.TwoWay
   };
   line.SetBinding(Line.X2Property, b);
   
   b = new Binding("Y")
   {
       Source = endPoint,
       Mode = BindingMode.TwoWay
   };
   line.SetBinding(Line.Y2Property, b);