c# - 使用来自另一个合并词典的合并词典中定义的样式

Question

下面你可以看到我是如何尝试通过合并字典来分离样式的(为了简洁起见，我跳过了命名空间)

App.xaml:

<Application.Resources>       
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary Source="Style/Colors.xaml" />
            <ResourceDictionary Source="Style/HeaderStyle.xaml"/>
        </ResourceDictionary.MergedDictionaries>            
    </ResourceDictionary>
</Application.Resources>

Colors.xaml:

<SolidColorBrush x:Key="DarkTextForeground" Color="#7471b9"/>

HeaderStyle.xaml:

<Style x:Key="HeaderTextBlockStyle" TargetType="TextBlock">
    <Setter Property="Foreground" Value="{StaticResource DarkTextForeground}"/>
    <Setter Property="FontWeight" Value="Black"/>
</Style>

在编译过程中出现以下错误:

Cannot find a Resource with the Name/Key DarkTextForeground

要使其正常工作，我们必须像这样将 Colors.xaml 合并到 HeaderStyle.xaml 中:

<ResourceDictionary.MergedDictionaries>
    <ResourceDictionary Source="Colors.xaml"/>
</ResourceDictionary.MergedDictionaries>

<Style x:Key="HeaderTextBlockStyle" TargetType="TextBlock">
    <Setter Property="Foreground" Value="{StaticResource DarkTextForeground}"/>
    <Setter Property="FontWeight" Value="Black"/>
</Style>

谁能给我解释一下，为什么我必须在 HeaderStyle.xaml 中引用 Colors.xaml？
合并字典？
我假设 Colors.xaml 在 HeaderStyle.xaml 之前加载，因此它应该对稍后定义的字典可见。

Answer 1

这是对 my question 的回应来自 msdn 论坛的 Erick Fleck:

In your first example each file is parsed independently and then added to the merged dictionary so they don't know anything about each other...similarly, the XAML in a merged dictionary cannot reference names in the 'parent' ResourceDictionary. In other words, you should think of a MergedDictionaries as a one-way reference.

我想这就是它的工作方式......