Q:

How to add xbf files to visual studio project

I have created a class library for Windows Universal Platform (Win 10 UWP).
The library houses some UserControls.
When I add the dll from this library to a Win 10 UWP app, and use the UserControls, it gives a XamlParseException as stated here in another question I posted
But when I reference the whole project, there is no exception and I can use the UserControl. This happens supposedly because there are xbf files which are not added to the Win 10 app project when I just reference the dll file.
In a certain project, I need to add the xbf files manually to the Win 10 app project, I cannot reference the whole project, I can only reference the dll and add the required files.
I tried creating a folder in Visual Studio project and adding the xbf files, and also tried creating folders with different names and copying the xbf files there in the "bin" directory through windows explorer. But no success.
So, how do I manuall add xbf files to a Windows 10 UWP project?
Update 1 :- XAML & Code for reference
public sealed partial class CustomPopupControl : UserControl
{
    internal CustomPopupControl()
    {
        this.InitializeComponent();    //-------CRASHES HERE-------
    }

    internal CustomPopupControl() : base()
    {
        Debug.WriteLine("CustomPopupControl");
        //
        //do some stuff
        //
        //
    }

    private void OnPopupLoaded(object sender, RoutedEventArgs e)
    {
        this.Popup_Container.HorizontalOffset = (Window.Current.Bounds.Width - Grid_Child.ActualWidth) / 2;
        this.Popup_Container.VerticalOffset = (Window.Current.Bounds.Height - Grid_Child.ActualHeight) / 2;
    }

    internal void OpenPopup()
    {
        Debug.WriteLine("OpenPopup");
        Popup_Container.IsOpen = true;

        var currentFrame = Window.Current.Content as Frame;
        var currentPage = currentFrame.Content as Page;
        currentPage.IsHitTestVisible = false;

        Debug.WriteLine("OpenPopup Done");
    }

    private void OnLayoutUpdated(object sender, object e)
    {
        if (Grid_Child.ActualWidth == 0 && Grid_Child.ActualHeight == 0)
        {
            return;
        }

        double ActualHorizontalOffset = Popup_Container.HorizontalOffset;
        double ActualVerticalOffset = Popup_Container.VerticalOffset;

        double NewHorizontalOffset = (Window.Current.Bounds.Width - Grid_Child.ActualWidth) / 2;
        double NewVerticalOffset = (Window.Current.Bounds.Height - Grid_Child.ActualHeight) / 2;

        if (ActualHorizontalOffset != NewHorizontalOffset || ActualVerticalOffset != NewVerticalOffset)
        {
            Popup_Container.HorizontalOffset = NewHorizontalOffset;
            Popup_Container.VerticalOffset = NewVerticalOffset;
        }
    }
}

XAML :-
<UserControl
x:Class="MyLibrary.CustomPopupControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:MyLibrary"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="300"
d:DesignWidth="400">

<Popup Name="Popup_Container" LayoutUpdated="OnLayoutUpdated">
    <Border BorderThickness="1" BorderBrush="{ThemeResource AppBarBorderThemeBrush}">
        <Grid Name="Grid_Child">
            <Grid Name="Grid_Content"  Height="300" Width="400" />
        </Grid>
    </Border>
</Popup>

I use the control directly in another app, as -
CustomPopupControl myctrl = new CustomPopupControl();
myctrl.OpenPopup();

A:

In addition to Thomas's answer, you need to check the "Generate library layout" option in the Build configuration under the project's Properties page.

The files we need to reference:

ClassLibrary1(Class Library name) Folder

ClassLibrary1.xr.xml
CustomPopupControl.xaml

ClassLibrary1.dll
ClassLibrary1.pri -> Package Resource Index file

Copy these files to anywhere and the UWP project just need to add reference to the ClassLibrary1.dll file in the Visual Studio, all of them will be added automatically.

It just throws a xaml parse exception when I try to use the UserControl on the "InitializeComponent()" method

Perhaps the .pri file is missing when you add the reference.

