Style App.xaml

Use this text in your App.xaml file

<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<!– Order is important –>

<ResourceDictionary Source=”pack://application:,,,/FlatStyle;component/Style/Colors.xaml” />
<ResourceDictionary Source=”pack://application:,,,/FlatStyle;component/Style/Fonts.xaml” />
<ResourceDictionary Source=”pack://application:,,,/FlatStyle;component/Style/BaseStyle.xaml” />

<ResourceDictionary Source=”pack://application:,,,/FlatStyle;component/Style/Button.xaml” />
<ResourceDictionary Source=”pack://application:,,,/FlatStyle;component/Style/Text.xaml” />
<ResourceDictionary Source=”pack://application:,,,/FlatStyle;component/Style/Scroll.xaml” />
<ResourceDictionary Source=”pack://application:,,,/FlatStyle;component/Style/Datagrid.xaml” />
<ResourceDictionary Source=”pack://application:,,,/FlatStyle;component/Style/ComboBox.xaml” />
<ResourceDictionary Source=”pack://application:,,,/FlatStyle;component/Style/CheckBox.xaml” />

</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
For Chrome window use this:
//Xaml
<Window.Resources>
<Style TargetType=”{x:Type local:MainWindow}”>
<Setter Property=”WindowChrome.WindowChrome”>
<Setter.Value>
<WindowChrome />
</Setter.Value>
</Setter>
<Setter Property=”Template”>
<Setter.Value>
<ControlTemplate TargetType=”{x:Type local:MainWindow}”>
<Grid>
<Border Background=”{StaticResource PrimaryBrush}”>
<ContentPresenter Content=”{TemplateBinding Content}” />
</Border>
<TextBlock Text=”{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Title}”
VerticalAlignment=”Top” HorizontalAlignment=”Left” Foreground=”{StaticResource BackgroundBrush}” FontWeight=”Black”
Margin=”12,8,0,0″ />
<Image Source=”{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Icon}” VerticalAlignment=”Top” HorizontalAlignment=”Left” WindowChrome.IsHitTestVisibleInChrome=”True” />
<StackPanel Orientation=”Horizontal” VerticalAlignment=”Top” HorizontalAlignment=”Right”>
<Button Content=”_” Style=”{StaticResource WindowButton}” Click=”MinimizeWindow” />
<Button Content=”☐” Style=”{StaticResource WindowButton}” Click=”MaximizeWindow” />
<Button Content=”X” Style=”{StaticResource WindowButton}” Click=”CloseWindow” />
</StackPanel>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>

//Code Behind
private void CloseWindow(object sender, RoutedEventArgs e)
{
Close();
}

private void MinimizeWindow(object sender, RoutedEventArgs e)
{
WindowState = WindowState.Minimized;
}

private void MaximizeWindow(object sender, RoutedEventArgs e)
{
switch (WindowState)
{
case WindowState.Normal:
WindowState = WindowState.Maximized;
break;

case WindowState.Maximized:
WindowState = WindowState.Normal;
break;
}
}