ResourceDictionary in separate library

Question

I have defined my resourceDictionary in a separate library as below

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:cultures="clr-namespace:My_Localization.Cultures"
    xmlns:properties="clr-namespace:My_Localization.Properties">

    <ObjectDataProvider x:Key="Resources" ObjectType="{x:Type cultures:CultureResources}" MethodName="GetResourceInstance"/>

    <ObjectDataProvider x:Key="CultureResourcesDS" ObjectType="{x:Type cultures:CultureResources}"/>

</ResourceDictionary>

I have used this library from another library as below (Header of xaml only)

<msRibbon:RibbonTab x:Class="Ribbon.Planner.PlannerRibbon"
    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" 
    xmlns:msRibbon="clr-namespace:Microsoft.Windows.Controls.Ribbon;assembly=RibbonControlsLibrary"
    mc:Ignorable="d" 
    d:DesignHeight="100" d:DesignWidth="500" Header="{Binding Path=Ribbon_About, Source={StaticResource Resources}}" 
    >
    <Grid>
     ...
     ...
     ...
    </Grid>

I have added the reference of My_Localization lib and I am only changing the header. All works fine but the only problem is that in design time I have "Header="{Binding Path=Ribbon_About, Source={StaticResource Resources}}" underlined. When I hover my mouse there is hint "The resource "Resources" could not be resolved"

Why is there an error like hint in my xaml? and then why does it all work fine?

My Solution structure

MainExe - Contains app.xaml. I have merged the resource dictionary here. No problems in xaml since the merge dictionary exists in app.xaml
My_Localization - Lib containing the resource dictionary (code above)
Lib1 - References My_Localization and there are problems in xaml as explained
Lib2 - References My_Localization and there are problems in xaml as explained
Lib3 - References My_Localization and there are problems in xaml as explained

I thought so but then is this correct that design time the xaml shows as though there are errors? Is there anyway to prevent this? — user2837961

Anders Anders · Accepted Answer · 2015-07-08T07:50:05

You need to provide a reference to the ResourceDictionary either in the app.xaml file or locally. Resources in app.xaml are available globally to all xaml files of the application.

For Xaml files in library projects the designer works a little differently.

At runtime it will be the app.xaml in the startup project that will be used for all assemblies. At designtime it will be the app.xaml of the local assembly. This means, you can add a app.xaml file to libraies, which will only be used by the Visual Studio Designer when rendering xaml files from that specific library (Set build action of file to Page).

To reference a ResourceDictionary do this:

<Application xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
    <Application.Resources>
        <ResourceDictionary>

            <!-- Other global resources -->

            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="pack://application:,,,/ASSEMBLYNAME;component/FOLDERPATH/RDNAME.xaml" />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>

Where ASSEMBLYNAME is the name of the assembly where the ResourceDictionary is (check properties of project).

Example:

Project with assembly name: "MyAssembly" and ResourceDictionary in folder path "Resources/RDs/MyRd.xaml"

Source="pack://application:,,,/MyAssembly;component/Resources/RDs/MyRd.xaml"

ResourceDictionary in separate library

3 Answers