Is WPFtoolkit compatible with .Net 4.5? - wpf

Question

I get this error when running the application.
XmlParseException Occured
Could not load file or assembly 'System.Windows.Controls.DataVisualization.Toolkit, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified
XAML
<UserControl x:Class="myNamespace.Views.ChartView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:chart="clr-namespace:System.Windows.Controls.DataVisualization.Charting;assembly=System.Windows.Controls.DataVisualization.Toolkit"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">
<Grid>
<Label Margin="10" Content="Scatter series" />
<chart:ScatterSeries DependentValueBinding="{Binding Value}"
IndependentValueBinding="{Binding Key}"
ItemsSource="{Binding PlotValues}" />
</Grid>
ViewModel:
public ObservableCollection<KeyValuePair<double, double>> PlotValues
{
get { return _plotValues; }
set { _plotValues = value; }
}

Answer 1

I think your problem is related to an issue/bug with the dependency detection in Visual Studio or MSBuild (related bug can be found here).
I've been able to reproduce your problem by doing the following:
Create a new WPF application
Create a new UserControl Library
Install the System.Windows.Controls.DataVisualization.Toolkit NuGet package on the UserControl Library (not the WPF application)
Add the scatter series
Add the custom user control containing the scatter series to the main window and running the application
The problem seems to be that without any reference to anything in the code (outside XAML), Visual Studio assumes that you are not using the assembly and therefore does not copy it to the output directory of the main application/project referencing it. More details can be found here, although these are references in ordinary code (C#, not XAML).
There are three workarounds which seems to make Visual Studio detect the dependency which I know of:
Give the control a name, and any name will do (my preferred solution)
Add a C# code reference to a controller in the Control Library (dummy code)
Add the NuGet or .dll reference to the actual application which is run
After having struggled with the same issue myself for a few hours, I believe to have discovered that Visual Studio is unable to detect the dependency on the dll based on a single usage directly in the XAML without a code reference (or a Name, which creates a code reference for you, allowing you to access the controller in the code-behind).
Edit:
I have reported this issue to Microsoft through Connect, so that they hopefully will fix it.