App.xaml

<Application x:Class="FocusTreeManager.App" 
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
             StartupUri="MainWindow.xaml" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             d1p1:Ignorable="d" 
             xmlns:d1p1="http://schemas.openxmlformats.org/markup-compatibility/2006"
             xmlns:vm="clr-namespace:FocusTreeManager.ViewModel"
             xmlns:dragablz="clr-namespace:Dragablz;assembly=Dragablz">
    <Application.Resources>
        <ResourceDictionary>
            <Style TargetType="{x:Type dragablz:TabablzControl}" BasedOn="{StaticResource MahAppsTabablzControlStyle}" />
            <vm:ViewModelLocator x:Key="Locator" />
            <ResourceDictionary.MergedDictionaries>
                <!-- MahApps.Metro resource dictionaries. Make sure that all file names are Case Sensitive! -->
                <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Controls.xaml" />
                <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Fonts.xaml" />
                <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Colors.xaml" />
                <!-- Accent and AppTheme setting -->
                <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Accents/Steel.xaml" />
                <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Accents/BaseDark.xaml" />
                <!-- Dragablez Theme -->
                <ResourceDictionary Source="pack://application:,,,/Dragablz;component/themes/mahapps.xaml" />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>