使用样式触发器设置嵌套对象的属性 [英] Use style trigger to set property of a nested object

问题描述

我在大画布上写了一个小多边形.当鼠标在画布上移动时，我想突出显示一个多边形.代码是这样的:

I have a small polygon written on the large canvas. I want to highlight a polygon when mouse is moving over the canvas. The code is like this:

<UserControl ...>
  <Canvas Name="canvas" Height="22" Width="22">
      <Canvas.Resources>
          <Style TargetType="Canvas">
              <Style.Triggers>
                  <Trigger Property="IsMouseOver" Value="false">
                      <Setter Property="polygon.Stroke" Value="#EEEEEE"/>
                  </Trigger>
                  <Trigger Property="IsMouseOver" Value="true">
                    <Setter Property="polygon.Stroke" Value="Aqua"/>
                </Trigger>
              </Style.Triggers>
          </Style>
      </Canvas.Resources>
      <Polygon Points="11,1 16,6 16,16 11,21" Name="polygon">
              <Polygon.Fill>
                  <SolidColorBrush Color="#EEEEEE"/>
              </Polygon.Fill>
      </Polygon>
  </Canvas>
</UserControl>

然而，setter 没有看到多边形".

However setter does not see the "polygon".

推荐答案

你不能像那样使用 Setters，如果你使用这种符号，引擎将寻找附加属性，如果没有Style.TargetType 是为点之前的类型的属性设置的.

You cannot use Setters like that, if you use this kind of notation the engine will look for an attached property, or if no Style.TargetType was set for a property on the type before the dot.

最简单的方法可能是将样式应用到多边形本身并使用绑定到 Canvas 的 DataTrigger 以便您可以触发其属性.>

The easiest thing to do is probably applying a style to the polygon itself and using a DataTrigger which binds to the Canvas so you can trigger on its properties.

  <Polygon Points="11,1 16,6 16,16 11,21" Name="polygon">
       <Polygon.Fill>
           <SolidColorBrush Color="#EEEEEE"/>
       </Polygon.Fill>
       <Polygon.Style>
          <Style TargetType="{x:Type Polygon}">
             <Style.Triggers> 
                <DataTrigger
                   Binding="{Binding Path=IsMouseOver,
                                     RelativeSource={RelativeSource
                                     AncestorType={x:Type Canvas}}}"
                   Value="True">
                   <Setter Property="Stroke" Value="Red"/>
                </DataTrigger>
             </Style.Triggers>
          </Style>
       <Polygon.Style>
  </Polygon>

这篇关于使用样式触发器设置嵌套对象的属性的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！