Using resource dictionary from a separate file gives me a designer error: Failed to set Source

Question

I'm trying to add a resource dictionary to a page but I keep getting a designer error in my xaml. The app runs fine with no issue but the designer error bothers me.

Here's how I did it. Both works fin at run time. But it's saying Failed to set "Source". Any clues?

That also gives an error to all the static resource I used from the resource dictionary.

Update:

This is another approach. Instead of directly adding it to the Page's resources, I added it to the Application.Resources still cant resolve the styles. I'm using VS2017 v15.4.4

Steps to reproduce:

1. List item
2. Create a new UWP Application Project (App1)
3. Create a new UWP Class Library (ClassLibrary1)
4. In ClassLibrary1, add a new ResourceDictionary (Dictionary1.xaml).

5. In Dictionary1.xaml, add a Style, let's say a button style.

   <Style TargetType="Button" x:Name="ButtonStyle1" x:Key="ButtonStyle1"> <Setter Propeprty="Background" Value="Red" /> </Style>

6. In the ClassLibrary1, add a new BlankPage (BlankPage1)

7. In the BlankPage1, add a button and use ButtonStyle1 `
8. In App1, merge the resource dictionary to App.Resources (inside App.xaml). <Application.Resources> <ResourceDictionary> <ResourceDictionary.MergedDictionary> <ResourceDictionary Source="ms-appx:///ClassLibrary1/Dictionary1.xaml" /> </ResourceDictionary.MergedDictionary> </ResourceDictionary> </Application.Resources>

9. Make the BlankPage1 the start page, go to App.xaml.cs and and change MainPage to BlankPage1: if (e.PrelaunchActivated == false) { if (rootFrame.Content == null) { // When the navigation stack isn't restored navigate to the first page, // configuring the new page by passing required information as a navigation // parameter rootFrame.Navigate(typeof(BlankPage1), e.Arguments); } // Ensure the current window is active Window.Current.Activate(); }

10. Run the application. It will run just fine. But the problem is in the designer where it cannot recognize the style from the resource dictionary.

Answer 1

I followed your steps and found a typo and an issue.

The typo: In Style step (Perhaps only in the sample), There is typo in the word 'Proeprty':

 <Style TargetType="Button" x:Name="ButtonStyle1" x:Key="ButtonStyle1">
        <Style.Setters>
            <Setter Property="Background" Value="Red" />
        </Style.Setters>
 </Style>

The issue in the way you are merging dictionary, it should be using the following syntax:

<Page.Resources>
        <ResourceDictionary>
           <ResourceDictionary.MergedDictionaries>
               <ResourceDictionary Source="Dictionary1.xaml" />
           </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
</Page.Resources>

After fixing both issues, Visual studio designer didn't complain about anything.

Did it fix the issue for you? If not then your steps to reproduce aren't complete.