wpf 运行时找不到基于之前定义的 StaticResource 的样式
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Style based on StaticResource previously defined is not found at runtime
提问by cguedel
I'm using Telerik's RadControls for WPF with implicit styling. The following style is defined in Themes/Windows8/Telerik.Windows.Controls.RibbonView.xaml:
我正在将 Telerik 的 RadControls 用于带有隐式样式的 WPF。以下样式定义在Themes/Windows8/Telerik.Windows.Controls.RibbonView.xaml：
<Style TargetType="telerikRibbonView:RadRibbonView" x:Key="RadRibbonViewStyle">
...
</Style>
My own styles and the Telerik default ones get merged like this in the assembly Lib.Windows.Controlsin the folder Themes:
我自己的样式和 Telerik 默认样式Lib.Windows.Controls在文件夹中的程序集中像这样合并Themes：
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Windows8/Telerik.Windows.Controls.RibbonView.xaml" />
<ResourceDictionary Source="MyTheme/TelerikCustomizations.xaml" />
<ResourceDictionary>
<!-- avoid optimization -->
<Style TargetType="{x:Type Rectangle}" />
</ResourceDictionary>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
And in TelerikCustomizations.xamlI define the following (empty, for testing purposes) style:
在TelerikCustomizations.xaml我定义以下（空，用于测试目的）样式：
<Style x:Key="MyThemeRadRibbonViewStyle" TargetType="{x:Type telerik:RadRibbonView}" BasedOn="{StaticResource ResourceKey=RadRibbonViewStyle}" />
Which results in the following exception at runtime:
这会在运行时导致以下异常：
'Provide value on 'System.Windows.Markup.StaticResourceHolder' threw an exception.' Line number '4' and line position '42'.
{"Cannot find resource named 'RadRibbonViewStyle'. Resource names are case sensitive."}
'Provide value on 'System.Windows.Markup.StaticResourceHolder' threw an exception.' Line number '4' and line position '42'.
{"Cannot find resource named 'RadRibbonViewStyle'. Resource names are case sensitive."}
Which led me to the following debugging statements in MyView.xaml.cs:
这导致我在 MyView.xaml.cs 中出现以下调试语句：
public ShellView()
{
var baseStyle = FindResource("RadRibbonViewStyle");
var inherited = FindResource("MyThemeRadRibbonViewStyle");
InitializeComponent();
}
Now the thing is: The exception is thrown on the second FindResourcecall. With the exact same message. However the RadRibbonViewStyleis clearly found in the first line of the constructor.
现在的事情是：在第二次FindResource调用时抛出异常。带有完全相同的消息。然而RadRibbonViewStyle，在构造函数的第一行中可以清楚地找到。
If it matters, the merged dictionary is actually merged in App.xaml a second time.
如果重要的话，合并的字典实际上第二次合并到 App.xaml 中。
I'm sure I'm missing something obvious, but I can't figure out what.
我确定我遗漏了一些明显的东西，但我不知道是什么。
App.xaml
应用程序.xaml
<Application x:Class="TestClient.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
StartupUri="Views/ShellView.xaml">
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="pack://application:,,,/Lib.Windows.Controls;component/Themes/MyTheme.xaml" />
<ResourceDictionary>
<!-- added to avoid optimization -->
<Style TargetType="{x:Type Rectangle}" />
</ResourceDictionary>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
</Application>
App.xaml.csdoes not overwrite the constructor. In fact it does not do anything.
App.xaml.cs不会覆盖构造函数。事实上，它没有做任何事情。
Update
更新
If I merge the Telerik dictionaries in TelerikCustomizations.xamlinstead of merging them in yet another dictionary (MyTheme.xaml), the exception disappears.
如果我将 Telerik 字典TelerikCustomizations.xaml合并而不是将它们合并到另一个字典 ( MyTheme.xaml) 中，异常就会消失。
However, I'd still like to know why this happens.
但是，我仍然想知道为什么会发生这种情况。
采纳答案by nemesv
You need to merge in the Windows8/Telerik.Windows.Controls.RibbonView.xamlin your MyTheme/TelerikCustomizations.xaml
你需要Windows8/Telerik.Windows.Controls.RibbonView.xaml在你的 MyTheme/TelerikCustomizations.xaml
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Windows8/Telerik.Windows.Controls.RibbonView.xaml" />
<ResourceDictionary>
<Style x:Key="MyThemeRadRibbonViewStyle" TargetType="{x:Type telerik:RadRibbonView}" BasedOn="{StaticResource ResourceKey=RadRibbonViewStyle}" />
</ResourceDictionary>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
And now you can use/merge this dictionary wherever you want.
现在您可以在任何地方使用/合并这本词典。
You need to do this because StaticResourceis not working between "sister" MergedDictionariesso you cannot reference a resource which was merged on the same level because the StaticResourcelooks only backwards to the directparents:
你需要这样做，因为StaticResource它不在“姐妹”之间工作， MergedDictionaries所以你不能引用在同一级别合并的资源，因为StaticResource它只向后看直接父母：
From MSDN:
从MSDN：
XAML resource references within a particular resource dictionary must reference a resource that has already been defined with a key, and that resource must appear lexically before the resource reference. Forward references cannot be resolved by a XAML resource reference
特定资源字典中的 XAML 资源引用必须引用已使用键定义的资源，并且该资源必须在词法上出现在资源引用之前。XAML 资源引用无法解析前向引用
But when using MergedDictionaries:
但是在使用时MergedDictionaries：
In the resource-lookup sequence, a MergedDictionaries dictionary is checked only after a check of allthe keyed resources of the ResourceDictionary that declared MergedDictionaries.
在资源查找序列中，仅在检查了声明 MergedDictionaries 的 ResourceDictionary的所有键控资源之后，才会检查 MergedDictionaries 字典。
