Using (merged) Resource Dictionary in C# Class Library Project

Question

How can I use a (merged) WPF Resource Dictionary in a C# class library project?

Here is what I did:

In my C# class library project I have a file Dictionary1.xaml like that:

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                >
    <Style x:Key="PluginFrameBorderStyle">
    ...
    </Style>
</ResourceDictionary>

Then, I have a UserControl file UserControl1.xaml where I try to use the Dictionary like that:

<UserControl x:Class="EditorPackageA.BackboneMemberB1Editor.BackboneMemberB1Editor"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         mc:Ignorable="d" 
         xmlns:local="clr-namespace:EditorPackageA.EditorBase"
         xmlns:prism="http://www.codeplex.com/prism" d:DesignWidth="690.4" d:DesignHeight="460.12">
<UserControl.Resources>
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary Source="/Dictionary1.xaml"/>
        </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
</UserControl.Resources>
...
</UserControl>

The project compiles but at runtime I get the error:

with the exception detail:

The same approach works when applied within a WPF project rather than a Class Library project .

What might be the solution here?

Important Addendum:

During design-time I see the effect of the used style that is embedded via the ResourceDictionary, hence the URI of the style and the dictionary must be correct!?

Answer 1

Try to use so called pack URI. I think that you have to explicitly specify where the resource dictionary is located.

<ResourceDictionary Source="pack://application:,,,/TheNameOfClassLibrary;component/Dictionary1.xaml"/>

In the case of a WPF project your approach works because WPF engine by default looks for resource in the assembly being executed (in exe).

Answer 2

You probably need to merge your library's resource dictionary in your application resources. You need to edit your App.xaml file and add something like:

<Application.Resources>
<ResourceDictionary>
  <ResourceDictionary.MergedDictionaries>
      <ResourceDictionary Source="pack://application:,,,/YourAssembly;component/Dictionary1.xaml" />
      </ResourceDictionary.MergedDictionaries>
  </ResourceDictionary>
</Application.Resources>

Answer 3

You should refer/link the ResourceDictionary xml file to the Source attribute with assembly and component name.
Use relative path as follows:

<ResourceDictionary Source="../Dictionary1.xaml" /> 

If it is not working, then try PACK URL

<ResourceDictionary Source="pack://application:,,,/Your.Base.AssemblyName;component/DictionaryFolder/Dictionary1.xaml" />

Hope it helps you