WPF Binding to Point in a BezierSegment

I have a viewmodel class which contains double X and a double Y variable and I would like to bind this to a BezierSegment and it seems not to work here is my code...

  public class TestViewModel:ViewModelBase
{
   public TestViewModel()
   {
       TStart = new TPoint {X=20.0,Y=45.0 };
       TEnd = new TPoint { X = 200.0, Y = 450.0 };

   }
    public TPoint TStart { get; set; }
    public TPoint TEnd { get; set; }

}


public class TPoint:ViewModelBase
{

    private double _X;
    public double X
    {
        get { return _X; }
        set
        {
            if (_X != value)
            {
                _X = value;
                RaisePropertyChanged("X");
            }
        }
    }

    private double _Y;
    public double Y
    {
        get { return _Y; }
        set
        {
            if (_Y != value)
            {
                _Y = value;
                RaisePropertyChanged("Y");
            }
        }
    }


}

}

and the XAML

 <Window.DataContext>
    <vm:TestViewModel />
</Window.DataContext>
<Grid>
    <Path Stroke="Black" StrokeThickness="3">
        <Path.Data>
            <PathGeometry>
                <PathGeometry.Figures>
                    <PathFigureCollection>
                        <PathFigure>
                            <PathFigure.Segments>
                                <PathSegmentCollection>
                   开发者_StackOverflow社区                 <BezierSegment>
                                        <BezierSegment.Point1>
                                            <Point X="{Binding TStart.X}" Y="{Binding TStart.Y}" />
                                        </BezierSegment.Point1>
                                        <BezierSegment.Point3>
                                            <Point X="{Binding TEnd.X}" Y="{Binding TEnd.Y}" />
                                        </BezierSegment.Point3>
                                    </BezierSegment>
                                </PathSegmentCollection>
                            </PathFigure.Segments>
                        </PathFigure>
                    </PathFigureCollection>
                </PathGeometry.Figures>
            </PathGeometry>
        </Path.Data>
    </Path>
</Grid>

I get an error that binding for X and Y can only be defined for DependencyProperties of a DependencyObject....

I do not want depend on the Windows Class Point ... although this would'nt even work for this example.

Can somebody tell my how I can bind my own point coordinates to BezierSegemnt Point1 Point2 Point3?

You would have to do it like this:

public class TPoint:ViewModelBase
{

    private double _X;
    public double X
    {
        get { return _X; }
        set
        {
            if (_X != value)
            {
                _X = value;
                RaisePropertyChanged("X");
                RaisePropertyChanged("P");
            }
        }
    }

    private double _Y;
    public double Y
    {
        get { return _Y; }
        set
        {
            if (_Y != value)
            {
                _Y = value;
                RaisePropertyChanged("Y");
                RaisePropertyChanged("P");
            }
        }
    }

    public Point P { get { return new Point(X,Y);}}    
}

and in the XAML:

<Window.DataContext>
    <vm:TestViewModel />
</Window.DataContext>
<Grid>
    <Path Stroke="Black" StrokeThickness="3">
        <Path.Data>
            <PathGeometry>
                <PathGeometry.Figures>
                    <PathFigureCollection>
                        <PathFigure>
                            <PathFigure.Segments>
                                <PathSegmentCollection>
                                    <BezierSegment Point1="{Binding TStart.P}" Point3="{Binding TEnd.P}"/>
                                </PathSegmentCollection>
                            </PathFigure.Segments>
                        </PathFigure>
                    </PathFigureCollection>
                </PathGeometry.Figures>
            </PathGeometry>
        </Path.Data>
    </Path>
</Grid>

let me know if it worked, I'm nowhere near a development environment

1. Wrapper for point --> class BindingPoint with implementation of 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. Binding to BezierSegment:

   private Path DefineBezierSegment(BindingPoint startPoint, BindingPoint endPoint, BindingPoint startBezierPoint, BindingPoint endBezierPoint)
   {
       BezierSegment spline = new BezierSegment {IsStroked = true};
   
       var b = new Binding("Point")
       {
           Source = startBezierPoint,
           Mode = BindingMode.TwoWay
       };
       BindingOperations.SetBinding(spline, BezierSegment.Point1Property, b);
   
       b = new Binding("Point")
       {
           Source = endBezierPoint,
           Mode = BindingMode.TwoWay
       };
       BindingOperations.SetBinding(spline, BezierSegment.Point2Property, b);
   
       b = new Binding("Point")
       {
           Source = endPoint,
           Mode = BindingMode.TwoWay
       };
       BindingOperations.SetBinding(spline, BezierSegment.Point3Property, b);
   
       var pColl = new PathSegmentCollection {spline};
   
       var pFig = new PathFigure(StartPort.Origin.Point, pColl, false);
   
       b = new Binding("Point")
       {
           Source = startPoint,
           Mode = BindingMode.TwoWay
       };
       BindingOperations.SetBinding(pFig, PathFigure.StartPointProperty, b);
   
       var pfColl = new PathFigureCollection { pFig };
   
       return new Path() {Data = new PathGeometry(pfColl)};
   }