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;
        }
    }
}

Answer 1

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