WPF绑定到BezierSegment中的Point

Question

我有一个viewmodel类，它包含double X和一个double Y变量，我想将它绑定到一个BezierSegment，它似乎不能在这里工作是我的代码...

  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");
            }
        }
    }


}

}

和XAML

 <Window.DataContext>
    <vm:TestViewModel />
</Window.DataContext>
<Grid>
    <Path Stroke="Black" StrokeThickness="3">
        <Path.Data>
            <PathGeometry>
                <PathGeometry.Figures>
                    <PathFigureCollection>
                        <PathFigure>
                            <PathFigure.Segments>
                                <PathSegmentCollection>
                                    <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>

我得到一个错误，只能为DependencyObject的DependencyProperties定义X和Y的绑定....

我不想依赖Windows Class Point ......虽然这对于这个例子甚至不起作用。

有人可以告诉我如何将自己的点坐标绑定到BezierSegemnt Point1 Point2 Point3吗？

Answer 1

你必须这样做：

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);}}    
}

在XAML中：

<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>

让我知道它是否有效，我远不是一个开发环境

Answer 2

1. 用于点的包装器 - >具有INotifyPropertyChanged接口实现的BindingPoint类

    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. 绑定到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)}; }