Question

我有一个viewmodel类，其中包含double X和double Y变量，我想将其绑定到BezierSegment，这似乎不适用于我的代码......

  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 ... 虽然这甚至不适用于这个例子。

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);}}    
}

并在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，我离开发环境不远

Answer 2

点包装 - ＆gt; BindingPoint与INotifyPropertyChanged接口的实现

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));
    }
}

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)};
}

WPF绑定到BezierSegment中的Point

2 个答案: