title: WPF project within another WPF project. Commands not working
body: <p>I have a project solution that contains 2 WPF projects. Project B is contained, and called, from within project A. </p>
  
  <p>The issue I'm having, is that the button commands on project B MainWindow are not hitting it's corresponding ViewModel. This doesn't happen when I run Project B as a standalone application (everything's fine).</p>
  
  <p>In both Projects A and B, I'm using Galasofts MVVM light framework, housing my view models in the static ViewModelLocator class.</p>
  
  <p>Any idea's would be greatly appreciated.
  Thanks</p>
  
  <p>Edit: For simplicity, I've just included 1 button.</p>
  
  <pre><code>ribbon:RibbonControl xmlns:Designer="clr-namespace:Nouvem.LabelDesigner.View.Designer"  x:Class="Nouvem.LabelDesigner.View.Designer.DesignerView"
          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
          xmlns:ribbon="clr-namespace:Microsoft.Windows.Controls.Ribbon;assembly=RibbonControlsLibrary"
          xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
          xmlns:d="http://schemas.microsoft.com/expression/blend/2008"           
          xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
          xmlns:command="http://www.galasoft.ch/mvvmlight"
          xmlns:sys="clr-namespace:System;assembly=mscorlib"
          xmlns:systemMessage="clr-namespace:Nouvem.LabelDesigner.View.SystemMessage"
          xmlns:loc="clr-namespace:Nouvem.Shared.Localisation;assembly=Nouvem.Shared"
          UseLayoutRounding="True"
          mc:Ignorable="d"
          d:DesignHeight="1000" d:DesignWidth="1200"
          Background="White"
          DataContext="{Binding LabelDesigner, Source={StaticResource Locator}}" &gt;
      &lt;Grid&gt;
          &lt;Button Command="{Binding TestCommand}"/&gt;
      &lt;/Grid&gt;
  
  &lt;/ribbon:RibbonControl&gt;
  </code></pre>
  
  <p>ViewModel</p>
  
  <pre><code> public RelayCommand TestCommand { get; set; }
  
   public LabelDesignerViewModel()
          {
              if (this.IsInDesignMode)
              {
                  return;
              }    
  
              this.TestCommand = new RelayCommand(() =&gt;
              {
                  // test - not hitting when called from another project
              });
  }
  `
  </code></pre>