WPF ControlTemplate Trigger - wpf

Question

All,
I am trying to set up a Template for a Window. What I want is to change the margin and the border thickness depending upon the state of the window. I am trying to do it using Trigger, but when I run the application, triggers don't fire. My question is, how can I make the triggers fire when the window state is changed?
The XAML I have is (I have removed most of the code to keep the posting simple):
<Window x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfApplication1" Background="#FFE8E8E8"
Style="{DynamicResource ChromeWindowStyle}"
mc:Ignorable="d"
Title="BaseWindow" Width="500" Height="300">
<WindowChrome.WindowChrome>
<WindowChrome ResizeBorderThickness="6" CaptionHeight="0" GlassFrameThickness="0" />
</WindowChrome.WindowChrome>
<Window.Resources>
<Style x:Key="ChromeWindowStyle" TargetType="{x:Type Window}">
<Setter Property="Foreground" Value="Black"/>
<Setter Property="Background" Value="#FFE8E8E8"/>
<Setter Property="WindowStyle" Value="None" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Window}">
<Border x:Name="MainBorder" Background="White" BorderBrush="Gray" BorderThickness="1">
<DockPanel LastChildFill="True">
<Border Height="30" DockPanel.Dock="Top">
<DockPanel LastChildFill="False">
<TextBlock Text="Heading" DockPanel.Dock="Left" VerticalAlignment="Center" />
<Button x:Name="CloseButton" Content="Close" DockPanel.Dock="Right" />
<Button x:Name="MaximizeButton" Content="Max" DockPanel.Dock="Right" />
<Button x:Name="MinButton" Content="Min" DockPanel.Dock="Right"/>
</DockPanel>
</Border>
<AdornerDecorator DockPanel.Dock="Bottom">
<ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}"
Content="{TemplateBinding Content}"
ContentStringFormat="{TemplateBinding ContentStringFormat}"/>
</AdornerDecorator>
</DockPanel>
</Border>
<!--This piece wont trigger - start -->
<ControlTemplate.Triggers>
<Trigger Property="WindowState" Value="Normal">
<Setter Property="Margin" Value="8" />
<Setter Property="BorderThickness" Value="1" />
</Trigger>
<Trigger Property="WindowState" Value="Maximized">
<Setter Property="Margin" Value="8" />
<Setter Property="BorderThickness" Value="0" />
</Trigger>
</ControlTemplate.Triggers>
<!--This piece wont trigger - end -->
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Grid>
</Grid>
</Window>

Answer 1

Your ControlTemplate.Triggers are trying to set properties on the ControlTemplate itself, which in-and-of itself is not a visual element. They need to explicitly specify the name of the Border control:
<ControlTemplate.Triggers>
<Trigger Property="WindowState" Value="Normal">
<Setter TargetName="MainBorder" Property="Margin" Value="8" />
<Setter TargetName="MainBorder" Property="BorderThickness" Value="1" />
</Trigger>
<Trigger Property="WindowState" Value="Maximized">
<Setter TargetName="MainBorder" Property="Margin" Value="8" />
<Setter TargetName="MainBorder" Property="BorderThickness" Value="0" />
</Trigger>
</ControlTemplate.Triggers>
EDIT: Oh ok, I'm still on 4.5.1, maybe that's new behavior? In that case I'd go the other way i.e. put DataTriggers on the border control itself:
<Style x:Key="ChromeWindowStyle" TargetType="{x:Type Window}">
<Setter Property="Foreground" Value="Black"/>
<Setter Property="WindowStyle" Value="None" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Window}">
<Border BorderBrush="Gray">
<Border.Style>
<Style TargetType="{x:Type Border}">
<Setter Property="Margin" Value="8" />
<Setter Property="BorderThickness" Value="1" />
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource AncestorType=Window}, Path=WindowState}" Value="Maximized">
<Setter Property="Margin" Value="8" />
<Setter Property="BorderThickness" Value="0" />
</DataTrigger>
</Style.Triggers>
</Style>
</Border.Style>
<DockPanel LastChildFill="True">
<Border Height="30" DockPanel.Dock="Top">
<DockPanel LastChildFill="False">
<TextBlock Text="Heading" DockPanel.Dock="Left" VerticalAlignment="Center" />
<Button x:Name="CloseButton" Content="Close" DockPanel.Dock="Right" />
<Button x:Name="MaximizeButton" Content="Max" DockPanel.Dock="Right" Click="MaximizeButton_Click"/>
<Button x:Name="MinButton" Content="Min" DockPanel.Dock="Right"/>
</DockPanel>
</Border>
<AdornerDecorator DockPanel.Dock="Bottom">
<ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}"
Content="{TemplateBinding Content}"
ContentStringFormat="{TemplateBinding ContentStringFormat}"/>
</AdornerDecorator>
</DockPanel>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>