DependencyProperty 和 WPF 设计器 [英] DependencyProperty and WPF Designer

问题描述

class MyLine : Shape {
    public static readonly DependencyProperty X11Property;
    public static readonly DependencyProperty X22Property;
    public static readonly DependencyProperty Y11Property;
    public static readonly DependencyProperty Y22Property;

    static MyLine() {
        X11Property = DependencyProperty.Register("X11", typeof(double), typeof(MyLine), new UIPropertyMetadata(double.NaN));
        X22Property = DependencyProperty.Register("X22", typeof(double), typeof(MyLine), new UIPropertyMetadata(double.NaN));
        Y11Property = DependencyProperty.Register("Y11", typeof(double), typeof(MyLine), new UIPropertyMetadata(double.NaN));
        Y22Property = DependencyProperty.Register("Y22", typeof(double), typeof(MyLine), new UIPropertyMetadata(double.NaN));
    }

    [TypeConverter(typeof(LengthConverter))]
    public double X11 { get { return (double)GetValue(X11Property); } set { SetValue(X11Property, value); } }
    [TypeConverter(typeof(LengthConverter))]
    public double X22 { get { return (double)GetValue(X22Property); } set { SetValue(X22Property, value); } }
    [TypeConverter(typeof(LengthConverter))]
    public double Y11 { get { return (double)GetValue(Y11Property); } set { SetValue(Y11Property, value); } }
    [TypeConverter(typeof(LengthConverter))]
    public double Y22 { get { return (double)GetValue(Y22Property); } set { SetValue(Y22Property, value); } }

    protected override System.Windows.Media.Geometry DefiningGeometry {
        get {
            var geometryGroup = new GeometryGroup();

            // Add line
            geometryGroup.Children.Add(new LineGeometry(new Point(X11, Y11), new Point(X22, Y22)));
            return geometryGroup;
        }
    }
}

为什么当我在 WPF 设计器(VS 2010)中更新myLine"坐标时，它不会自动更新(实时)?

Why when I update the "myLine" coordinates in WPF designer(VS 2010), it does not update it automatically(live)?

当使用默认的Line"WPF 对象时，它们会在 XAML/设计视图中更改(编辑)XAML 代码时自动更新.

When using default "Line" WPF objects, they are automatically updated when the XAML code is changed(edited) in XAML/Design view.

推荐答案

由于这些属性影响渲染，你应该在元数据中指定:

Since these properties affect rendering, you should specify it in the metadata:

X11Property = DependencyProperty.Register("X11", typeof(double), typeof(DirectionLine), new FrameworkPropertyMetadata(double.NaN, FrameworkPropertyMetadataOptions.AffectsRender));

我不确定设计师是否考虑到它是否足够，但值得一试......

I'm not sure it will be enough for the designer to take it into account, but it's worth a try...

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