ControlTemplate中是否可以通过xaml绑定PolyLineSegment.Points？

Question

最近，我需要更改 Thumb 的模板。我想像这样将其形状更改为三角形。我使用一个 Path 作为它的 ControlTemplate。这是代码：

 <Thumb
        Width="100"
        Height="30"
        HorizontalAlignment="Left"
        VerticalAlignment="Top">
        <Thumb.Template>
            <ControlTemplate>
                <Path Fill="Red">
                    <Path.Data>
                        <PathGeometry>
                            <PathFigure>
                                <PolyLineSegment>
                                    <PolyLineSegment.Points>
                                        <PointCollection>
                                            <Point X="0" Y="0" />
                                            <Point X="{TemplateBinding Width}" Y="{TemplateBinding Height}" />
                                            <Point X="0" Y="{TemplateBinding Height}" />
                                        </PointCollection>
                                    </PolyLineSegment.Points>
                                </PolyLineSegment>
                            </PathFigure>
                        </PathGeometry>
                    </Path.Data>
                </Path>
            </ControlTemplate>
        </Thumb.Template>
    </Thumb>

您可以看到我尝试将 PolyLineSegment.Points 绑定到 Thumb 的宽度和高度。

但是 Visual Studio 抛出一个错误：

"Error Object of type 'System.Windows.TemplateBindingExpression'

cannot be converted to type 'System.Double'."

不知道为什么不行。谁能给我提示？

Answer 1

终于找到问题所在了。我发现这是因为 Point.X 或 Point.Y 不是 Dependency 属性。所以这就是绑定不起作用的原因。

我通过绑定到 LineSegment 来解决这个问题。

 <ControlTemplate>
                <Path Fill="{TemplateBinding Background}">
                    <Path.Data>
                        <PathGeometry>
                            <PathFigure StartPoint="0 0">
                                <LineSegment>
                                    <LineSegment.Point>
                                        <MultiBinding Converter="{StaticResource thumb2PointConverter}" ConverterParameter="rightBottom">
                                            <Binding Path="Width" RelativeSource="{RelativeSource Mode=FindAncestor, AncestorType=Thumb}" />
                                            <Binding Path="Height" RelativeSource="{RelativeSource Mode=FindAncestor, AncestorType=Thumb}" />
                                        </MultiBinding>
                                    </LineSegment.Point>
                                </LineSegment>

                                <LineSegment>
                                    <LineSegment.Point>
                                        <MultiBinding Converter="{StaticResource thumb2PointConverter}" ConverterParameter="leftBottom">
                                            <Binding Path="Width" RelativeSource="{RelativeSource Mode=FindAncestor, AncestorType=Thumb}" />
                                            <Binding Path="Height" RelativeSource="{RelativeSource Mode=FindAncestor, AncestorType=Thumb}" />
                                        </MultiBinding>
                                    </LineSegment.Point>
                                </LineSegment>
                            </PathFigure>
                        </PathGeometry>
                    </Path.Data>
                </Path>
            </ControlTemplate>

ControlTemplate中是否可以通过xaml绑定PolyLineSegment.Points？

Is it possible to bind PolyLineSegment.Points through xaml in ControlTemplate?

wpf

xaml

controls

templates