Where is my Microsoft.Windows.Themes assembly?

Question

I wrote a user control in XAML and after it gets compiled into C# the resulting C# has this line:

using Microsoft.Windows.Themes;

Which throws an error now:

The type or namespace name 'Themes' does not exist in the namespace 'Microsoft.Windows' (are you missing an assembly reference?)

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.

However, the Add Reference dialog does not contain Microsoft.Windows.Themes. Is this not part of .NET?

Here's an example XAML user control that causes this problem:

<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">

    <StackPanel>
        <Menu VerticalAlignment="Top" Background="{x:Null}">
            ... // Just static menu items.
        </Menu>
    </StackPanel>

</UserControl>

And C# code behind it:

using System;
using System.Windows.Controls;

namespace GG.UserControls
{
    /// <summary>
    /// Interaction logic for MainMenu.xaml
    /// </summary>
    public partial class MainMenu : UserControl
    {
        public MainMenu()
        {
            InitializeComponent();
        }
    }
}

Here's an example of compiled C#:

#pragma checksum "..\..\..\..\UserControls\MainMenu.xaml" "{406ea660-64cf-4c82-b6f0-42d48172a799}" "5A85C5B16565514165AD23641F944BC6"
//------------------------------------------------------------------------------
// <auto-generated>
//     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.
// </auto-generated>
//------------------------------------------------------------------------------

using GG;
using GG.UserControls;
using Microsoft.Windows.Shell;
using Microsoft.Windows.Themes; // <---- 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 {


    /// <summary>
    /// ChangesetHistory
    /// </summary>
    public partial class MainMenu : System.Windows.Controls.UserControl, System.Windows.Markup.IComponentConnector {

        private bool _contentLoaded;

        /// <summary>
        /// InitializeComponent
        /// </summary>
        [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;
        }
    }
}

Solution

Microsoft.Windows.Themes is found in the theme-specific PresentationFramework assemblies. You'll want to add a reference to one of the following depending on which one is referenced in your XAML:

• PresentationFramework.Aero.dll
• PresentationFramework.AeroLite.dll
• PresentationFramework.Classic.dll
• PresentationFramework.Luna.dll
• PresentationFramework.Royale.dll

Comments

[Tower]

"What's referenced in your XAML"? I have no references to any such things. Which one should I pick? I'll post my XAML in my question in a second.

[BoltClock]

Hmm, I dropped your code in a fresh user control in a fresh WPF project and it doesn't produce that using statement for me. Where exactly in your code does the using statement appear?

[Tower]

I attached the compiled XAML -> C# code. It shows the using. I've tried Clean Solution and then Rebuild Solution without difference.

[BoltClock]

I suspect there's something within your Menu that contains theme-specific elements. Try just adding a reference to PresentationFramework.Aero.dll and see what happens.

[Tower]

Works fine after I added PresentationFramework.Aero.dll. Hmm.

[eran otzap]

@Tower i don't know if i understood you right and if you still needed it, this is how you reference it via XAML , after adding the Reference to your project of course . xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Wind‌​ows.Themes;assembly=‌​PresentationFramewor‌​k.Aero"

[eran otzap]

I'm searching under PresentationFramework.dll using reflector , i can't seem to locate any of the themes .dlls where are they physically located ?

[New Bee]

Thank you for this, in VS2012 Windows.Themes was working then i updated to VS2013 (Worst mistake eva)

[eran otzap]

@Tower where can i physically find PresentationFramework.Aero.dll ?

[eran otzap]

well i wasn't able to physically locate it , but you can download it from here : dllme.com/dll/download/6959/PresentationFramework.Aero.dll

[Edgar]

I had the same problem and I confirm: Works fine after I added PresentationFramework.Aero.dll