In WPF how do I reference a static resource that is defined in a different XAML file? It's in the same project.
The other XAML file will need to be a resource dictionary. You merge it into the current file using the MergedDictionaries property of the current ResourceDictionary. See Merged Resource Dictionaries on MSDN. Their example:
<Page.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="myresourcedictionary.xaml"/>
<ResourceDictionary Source="myresourcedictionary2.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Page.Resources>
Then within that Page object you can reference static resources defined in myresourcedictionary.xaml
or in myresourcedictionary2.xaml
.