title: Where is my Microsoft.Windows.Themes assembly?
body: <p>I wrote a user control in XAML and after it gets compiled into C# the resulting C# has this line:</p>
  
  <pre><code>using Microsoft.Windows.Themes;
  </code></pre>
  
  <p>Which throws an error now:</p>
  
  <blockquote>
    <p>The type or namespace name 'Themes' does not exist in the namespace
    'Microsoft.Windows' (are you missing an assembly reference?)</p>
  </blockquote>
  
  <p>I figured since I can't affect the output of compiled C# (there's nothing to remove from XAML), I would just add that as Reference.</p>
  
  <p>However, the Add Reference dialog does not contain <code>Microsoft.Windows.Themes</code>. Is this not part of .NET?</p>
  
  <p>Here's an example XAML user control that causes this problem:</p>
  
  <pre><code>&lt;UserControl x:Class="GG.UserControls.MainMenu"
               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" 
               mc:Ignorable="d" 
               d:DesignHeight="300" d:DesignWidth="300"&gt;
  
      &lt;StackPanel&gt;
          &lt;Menu VerticalAlignment="Top" Background="{x:Null}"&gt;
              ... // Just static menu items.
          &lt;/Menu&gt;
      &lt;/StackPanel&gt;
  
  &lt;/UserControl&gt;
  </code></pre>
  
  <p>And C# code behind it:</p>
  
  <pre><code>using System;
  using System.Windows.Controls;
  
  namespace GG.UserControls
  {
      /// &lt;summary&gt;
      /// Interaction logic for MainMenu.xaml
      /// &lt;/summary&gt;
      public partial class MainMenu : UserControl
      {
          public MainMenu()
          {
              InitializeComponent();
          }
      }
  }
  </code></pre>
  
  <p>Here's an example of compiled C#:</p>
  
  <pre><code>#pragma checksum "..\..\..\..\UserControls\MainMenu.xaml" "{406ea660-64cf-4c82-b6f0-42d48172a799}" "5A85C5B16565514165AD23641F944BC6"
  //------------------------------------------------------------------------------
  // &lt;auto-generated&gt;
  //     This code was generated by a tool.
  //     Runtime Version:4.0.30319.17020
  //
  //     Changes to this file may cause incorrect behavior and will be lost if
  //     the code is regenerated.
  // &lt;/auto-generated&gt;
  //------------------------------------------------------------------------------
  
  using GG;
  using GG.UserControls;
  using Microsoft.Windows.Shell;
  using Microsoft.Windows.Themes; // &lt;---- WTF?
  using System;
  using System.Diagnostics;
  using System.Windows;
  using System.Windows.Automation;
  using System.Windows.Controls;
  using System.Windows.Controls.Primitives;
  using System.Windows.Data;
  using System.Windows.Documents;
  using System.Windows.Ink;
  using System.Windows.Input;
  using System.Windows.Markup;
  using System.Windows.Media;
  using System.Windows.Media.Animation;
  using System.Windows.Media.Effects;
  using System.Windows.Media.Imaging;
  using System.Windows.Media.Media3D;
  using System.Windows.Media.TextFormatting;
  using System.Windows.Navigation;
  using System.Windows.Shapes;
  using System.Windows.Shell;
  
  
  namespace GG.UserControls {
  
  
      /// &lt;summary&gt;
      /// ChangesetHistory
      /// &lt;/summary&gt;
      public partial class MainMenu : System.Windows.Controls.UserControl, System.Windows.Markup.IComponentConnector {
  
          private bool _contentLoaded;
  
          /// &lt;summary&gt;
          /// InitializeComponent
          /// &lt;/summary&gt;
          [System.Diagnostics.DebuggerNonUserCodeAttribute()]
          [System.CodeDom.Compiler.GeneratedCodeAttribute("PresentationBuildTasks", "4.0.0.0")]
          public void InitializeComponent() {
              if (_contentLoaded) {
                  return;
              }
              _contentLoaded = true;
              System.Uri resourceLocater = new System.Uri("/GG;component/usercontrols/mainmenu.xaml", System.UriKind.Relative);
  
              #line 1 "..\..\..\..\UserControls\MainMenu.xaml"
              System.Windows.Application.LoadComponent(this, resourceLocater);
  
              #line default
              #line hidden
          }
  
          [System.Diagnostics.DebuggerNonUserCodeAttribute()]
          [System.CodeDom.Compiler.GeneratedCodeAttribute("PresentationBuildTasks", "4.0.0.0")]
          [System.ComponentModel.EditorBrowsableAttribute(System.ComponentModel.EditorBrowsableState.Never)]
          [System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Design", "CA1033:InterfaceMethodsShouldBeCallableByChildTypes")]
          [System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Maintainability", "CA1502:AvoidExcessiveComplexity")]
          [System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1800:DoNotCastUnnecessarily")]
          void System.Windows.Markup.IComponentConnector.Connect(int connectionId, object target) {
              this._contentLoaded = true;
          }
      }
  }
  </code></pre>