StaticResource错误：`{DependencyProperty.UnsetValue}'不是属性的有效值

Question

不知道我在这里做错了什么。

我在Colors中定义了ResourceDictionary：Colors.xaml：

<ResourceDictionary 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Color x:Key="Normal">#FF404040</Color>
</ResourceDictionary>

然后在Brushes.xaml中使用：

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="Colors.xaml"/>
        <!-- here I may have more colors-->
    </ResourceDictionary.MergedDictionaries>
    <SolidColorBrush x:Key="Color" Color="{StaticResource Normal}" />
    <!-- here I may have more brushes-->
</ResourceDictionary>

然后Brushes合并在Generic.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="Brushes.xaml"/>
        <!-- here I may have more resources-->
    </ResourceDictionary.MergedDictionaries>
</ResourceDictionary>

现在，如果我使用Brushes，就像这样说Border Style：

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Style x:Key="BorderContainer" TargetType="{x:Type Border}">
        <Setter Property="Background" Value="{StaticResource Color}"/>
    </Style>
</ResourceDictionary>

我必须使用它作为DynamicResource，但如果用作StaticResource然后我在运行时遇到此错误：

{DependencyProperty.UnsetValue}' is not a valid value for property 'Background'

我希望在我的应用程序中随处使用StaticResource for Brushes。

Answer 1

如果要在ResourceDictionary中使用StaticResource，则需要将Brushes.xaml ResourceDictionary合并到ResourceDictionary中，您可以在其中定义Border样式，就像在Brushes.xaml中使用Colors.xaml一样：

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <!-- "Include" Brushes -->
    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="Brushes.xaml" />
    </ResourceDictionary.MergedDictionaries>

    <Style x:Key="BorderContainer" TargetType="{x:Type Border}">
        <Setter Property="Background" Value="{StaticResource Color}" />
    </Style>
</ResourceDictionary>

有关Static-和DynamicResource之间差异的更多信息，请参阅this answer。