WPF：根据样式所在位置，ContentPresenter的前景色意外地发生变化

Question

我在使用ContentPresenter时遇到了问题，具体表现为样式文件是放在Window.Resources中还是ResourceDictionary中会导致不同的结果。具体来说，我将默认TextBlock的前景色设置为黑色，然后在默认按钮样式中将前景色值设置为白色。

如果样式文件像这样存在于页面中，它们可以正常工作：

<Window
 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero"
 x:Class="TestBed.MainWindow"
 x:Name="Window"
 Title="MainWindow"
 Width="640" Height="480">
 <Window.Resources>
  <Style TargetType="{x:Type TextBlock}">
     <Setter Property="Foreground" Value="Black" />
   </Style>
  <Style x:Key="ButtonFocusVisual">
   <Setter Property="Control.Template">
    <Setter.Value>
     <ControlTemplate>
      <Rectangle Stroke="Black" StrokeDashArray="1 2" StrokeThickness="1" Margin="2" SnapsToDevicePixels="true"/>
     </ControlTemplate>
    </Setter.Value>
   </Setter>
  </Style>
  <LinearGradientBrush x:Key="ButtonNormalBackground" EndPoint="0,1" StartPoint="0,0">
   <GradientStop Color="#F3F3F3" Offset="0"/>
   <GradientStop Color="#EBEBEB" Offset="0.5"/>
   <GradientStop Color="#DDDDDD" Offset="0.5"/>
   <GradientStop Color="#CDCDCD" Offset="1"/>
  </LinearGradientBrush>
  <SolidColorBrush x:Key="ButtonNormalBorder" Color="#FF707070"/>
  <Style TargetType="{x:Type Button}">
   <Setter Property="FocusVisualStyle" Value="{StaticResource ButtonFocusVisual}"/>
   <Setter Property="Background" Value="{StaticResource ButtonNormalBackground}"/>
   <Setter Property="BorderBrush" Value="{StaticResource ButtonNormalBorder}"/>
   <Setter Property="BorderThickness" Value="1"/>
   <Setter Property="Foreground" Value="White"/>
   <Setter Property="HorizontalContentAlignment" Value="Center"/>
   <Setter Property="VerticalContentAlignment" Value="Center"/>
   <Setter Property="Padding" Value="1"/>
   <Setter Property="Template">
    <Setter.Value>
     <ControlTemplate TargetType="{x:Type Button}">
      <Microsoft_Windows_Themes:ButtonChrome x:Name="Chrome" SnapsToDevicePixels="true" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" RenderDefaulted="{TemplateBinding IsDefaulted}" RenderMouseOver="{TemplateBinding IsMouseOver}" RenderPressed="{TemplateBinding IsPressed}">
       <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" RecognizesAccessKey="True"/>
      </Microsoft_Windows_Themes:ButtonChrome>
      <ControlTemplate.Triggers>
       <Trigger Property="IsKeyboardFocused" Value="true">
        <Setter Property="RenderDefaulted" TargetName="Chrome" Value="true"/>
       </Trigger>
       <Trigger Property="ToggleButton.IsChecked" Value="true">
        <Setter Property="RenderPressed" TargetName="Chrome" Value="true"/>
       </Trigger>
       <Trigger Property="IsEnabled" Value="false">
        <Setter Property="Foreground" Value="#ADADAD"/>
       </Trigger>
      </ControlTemplate.Triggers>
     </ControlTemplate>
    </Setter.Value>
   </Setter>
  </Style>
 </Window.Resources>
 <StackPanel x:Name="LayoutRoot">
  <Button Content="Button"  />  
 </StackPanel>
</Window>

但是如果我将相同的样式移动到ResourceDictionary中，按钮的前景色将变为黑色。

更新后的MainWindow：

<Window
 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero"
 x:Class="TestBed.MainWindow"
 x:Name="Window"
 Title="MainWindow"
 Width="640" Height="480">

 <StackPanel x:Name="LayoutRoot">
  <Button Content="Button" />  
 </StackPanel>
</Window>

ResourceDictionary:

<ResourceDictionary
 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
 xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero" 
 xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
 xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
 mc:Ignorable="d">

  <Style TargetType="{x:Type TextBlock}">
  <Setter Property="Foreground" Value="Black" />
  </Style>
  <Style x:Key="ButtonFocusVisual">
   <Setter Property="Control.Template">
    <Setter.Value>
     <ControlTemplate>
      <Rectangle Stroke="Black" StrokeDashArray="1 2" StrokeThickness="1" Margin="2" SnapsToDevicePixels="true"/>
     </ControlTemplate>
    </Setter.Value>
   </Setter>
  </Style>
  <LinearGradientBrush x:Key="ButtonNormalBackground" EndPoint="0,1" StartPoint="0,0">
   <GradientStop Color="#F3F3F3" Offset="0"/>
   <GradientStop Color="#EBEBEB" Offset="0.5"/>
   <GradientStop Color="#DDDDDD" Offset="0.5"/>
   <GradientStop Color="#CDCDCD" Offset="1"/>
  </LinearGradientBrush>
  <SolidColorBrush x:Key="ButtonNormalBorder" Color="#FF707070"/>
  <Style TargetType="{x:Type Button}">
   <Setter Property="FocusVisualStyle" Value="{StaticResource ButtonFocusVisual}"/>
   <Setter Property="Background" Value="{StaticResource ButtonNormalBackground}"/>
   <Setter Property="BorderBrush" Value="{StaticResource ButtonNormalBorder}"/>
   <Setter Property="BorderThickness" Value="1"/>
   <Setter Property="Foreground" Value="White"/>
   <Setter Property="HorizontalContentAlignment" Value="Center"/>
   <Setter Property="VerticalContentAlignment" Value="Center"/>
   <Setter Property="Padding" Value="1"/>
   <Setter Property="Template">
    <Setter.Value>
     <ControlTemplate TargetType="{x:Type Button}">
      <Microsoft_Windows_Themes:ButtonChrome x:Name="Chrome" SnapsToDevicePixels="true" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" RenderDefaulted="{TemplateBinding IsDefaulted}" RenderMouseOver="{TemplateBinding IsMouseOver}" RenderPressed="{TemplateBinding IsPressed}">
       <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" RecognizesAccessKey="True"/>
      </Microsoft_Windows_Themes:ButtonChrome>
      <ControlTemplate.Triggers>
       <Trigger Property="IsKeyboardFocused" Value="true">
        <Setter Property="RenderDefaulted" TargetName="Chrome" Value="true"/>
       </Trigger>
       <Trigger Property="ToggleButton.IsChecked" Value="true">
        <Setter Property="RenderPressed" TargetName="Chrome" Value="true"/>
       </Trigger>
       <Trigger Property="IsEnabled" Value="false">
        <Setter Property="Foreground" Value="#ADADAD"/>
       </Trigger>
      </ControlTemplate.Triggers>
     </ControlTemplate>
    </Setter.Value>
   </Setter>
  </Style>
</ResourceDictionary>

这是我的 App.xaml 文件，因为有人可能会询问：

<Application
 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 x:Class="TestBed.App"
 StartupUri="MainWindow.xaml">
 <Application.Resources>
  <!-- Resources scoped at the Application level should be defined here. -->
  <ResourceDictionary>
   <ResourceDictionary.MergedDictionaries>
    <ResourceDictionary Source="ResourceDictionary.xaml"/>
   </ResourceDictionary.MergedDictionaries>
  </ResourceDictionary>
 </Application.Resources>
</Application>

任何帮助都将不胜感激 :)

- VLTII

Answer 1

刚意识到我从来没有回答过这个问题。简短的回答是，你应该始终使用标签而不是文本块，因为文本块实际上不是控件。

- VLTII

---

谢谢提供信息，我一直在努力更改自定义数据表的前景色。 - noobie

Answer 2

我们是在讨论它在设计时还是运行时表现得奇怪。我以前在Visual Studio设计器中遇到过问题...特别是在我进行运行时之前，App.Xaml无法正常工作。

- Goblin

---

抱歉，我可能没有清楚地表达问题 - 这是在运行时。如果样式在窗口上，按钮的文本颜色按预期工作并且是白色的。一旦我将其移出窗口并放入资源字典中，文本就变成了黑色。 - VLTII