Can't apply WPF theme on the window itself

Question

I'm trying to apply the ExpressionDark theme from the Windows Presentation Foundation (WPF) CodePlex project.

I have added the file ExpressionDark.xaml in a Themes subfolder, and changed my App.xaml file to reference this file :

<Application.Resources>
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary
                Source="Themes/ExpressionDark.xaml" />
        </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
</Application.Resources>

When I run the program, the styles are applied to all controls but not the window itself. The window's background remains white. What I understand is that the style applies to Window class, but not to derived class.

To workaround this issue, I've try to create a new style in my app.xaml file, in order to inherits the Windows style for my custom window class :

<Application.Resources>
    <ResourceDictionary>
        <Style
            TargetType="{x:Type local:MainWindow}"
            BasedOn="{StaticResource {x:Type Window}}" />
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary
                Source="Themes/ExpressionDark.xaml" />
        </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
</Application.Resources>

The result is strictly identical.

I've also try the advise from WPF: Adventures in Theming (Part 2) . I added to my window definition :

<Window
    x:Class="MyProject.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:vm="clr-namespace:MyProject.ViewModel"
    Title="MainWindow"
    Height="350"
    Width="525"
    Style="{DynamicResource {x:Type Window}}" />

No more success.

What is missing?

PS: don't know if it matters, but my window's child is a Grid.

Answer 1

Specify Background using dynamic resource in the Window XAML

<Window x:Class="HellowWorld.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Hellow World" Height="614" Width="821"
        Background="{DynamicResource WindowBackgroundBrush}">

Answer 2

我上次检查主题中没有Window样式。