使用路径作为附加属性的 WPF 自定义形状按钮模板

Question

我对 WPF 还是很陌生。我正在尝试创建一个按钮模板，该模板使用按钮形状的路径数据。我的应用程序有几个按钮可以执行类似的任务，但需要不同的形状。我正在尝试创建一个附加属性，它将路径数据传递给我的模板。到目前为止我所得到的:

附带属性:

Public Class CustomShapeButton
    Inherits Button
Public Shared PathDataProperty As DependencyProperty = DependencyProperty.RegisterAttached("PathData", GetType(Path), GetType(CustomShapeButton), New PropertyMetadata(Nothing))

Public Shared Sub SetPathData(obj As DependencyObject, value As Path)
    obj.SetValue(PathDataProperty, value)
End Sub
Public Shared Function GetPathData(obj As DependencyObject) As Path
    Return DirectCast(obj.GetValue(PathDataProperty), Path)
End Function
End Class

以及位于我的资源字典中的按钮模板:

    <Style x:Key="TransparentNavButton" TargetType="{x:Type Button}">
    <Setter Property="FontSize" Value="16"/>
    <Setter Property="FontWeight" Value="Bold"/>
    <Setter Property="BorderBrush" Value="Transparent"/>
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Button}">
                <Grid>
                    <Path x:Name="pth" Data="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=(hmi:CustomShapeButton.PathData)}" Stroke="Black" Stretch="Fill"/>
                    <ContentPresenter x:Name="ButtonContentPresenter" VerticalAlignment="Center" HorizontalAlignment="Right" Margin="0,0,4,0"/>
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter TargetName="pth" Property="Fill" Value="#60FF0000"/>
                        <Setter TargetName="pth" Property="Stroke" Value="Blue"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

然后尝试实现它是这样的:

<Button Content="Button" Width="60" Height="50" Style="{StaticResource TransparentNavButton}">
    <hmi:CustomShapeButton.PathData>
        <Path Data="M1 1 L20 0 L20 20 L0 20 Z"/>
    </hmi:CustomShapeButton.PathData>
</Button>

我似乎无法让路径数据显示在按钮上。我错过了什么？

Answer 1

您的问题是您正在创建类型为 Path 的附加属性。但将其分配给 PathData模板中的属性，类型为 Geometry .要解决此问题，请像这样更改附加的属性声明:

Public Class CustomShapeButton
Public Shared PathDataProperty As DependencyProperty = DependencyProperty.RegisterAttached("PathData", GetType(Geometry), GetType(CustomShapeButton), New PropertyMetadata(Nothing))

Public Shared Sub SetPathData(obj As DependencyObject, value As Geometry)
    obj.SetValue(PathDataProperty, value)
End Sub
Public Shared Function GetPathData(obj As DependencyObject) As Geometry
    Return DirectCast(obj.GetValue(PathDataProperty), Geometry)
End Function
End Class

然后像这样使用它:

<Button Content="Button" Width="60" Height="50"
        hmi:CustomShapeButton.PathData="M1 1 L20 0 L20 20 L0 20 Z"
        Style="{StaticResource TransparentNavButton}" />

还有一件事要注意:您的 CustomShapeButton类不需要继承自 Button - 事实上，它根本不需要继承任何东西。但是，如果您想创建自己的具有 PathData 的派生按钮类属性，那么你可以从 Button 继承，在这种情况下，您将声明 PathData作为常规依赖属性而不是附加属性。