title: ToggleButton IsChecked Trigger with Storyboard Targetname Issue
body: <p>I tried to trigger a Storyboard, whichs TargetName is set to a ScrollViewer, with the ToggleButton IsChecked Property, but it says that the TargetName could not be found in the namespace of ControlTemplate.. what makes sence, but I don't know how to refer it correctly.</p>
  
  <p>So I wanted following to get:</p>
  
  <ul>
  <li>ToggButton Click (IsChecked = true) --> ScrollViewer animates/changes trough Storyboard (StoryBoard1)</li>
  <li>ToggButton Click Again (IsChecked = false) --> ScrollViewer animates/changes back trough Storyboard (StoryBoard2)</li>
  </ul>
  
  <p>Here's my XAML:</p>
  
  <pre><code>&lt;Window x:Class="myProject.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:ignore="http://www.galasoft.ch/ignore"
                    xmlns:view="clr-namespace:Messenger4u.View"
                    mc:Ignorable="d ignore"&gt;
  
  &lt;Window.Resources&gt;
      &lt;ResourceDictionary&gt;
  
          &lt;Storyboard x:Key="Storyboard1" SpeedRatio="3"&gt;
              &lt;ThicknessAnimationUsingKeyFrames Storyboard.TargetProperty="(FrameworkElement.Margin)" 
                            Storyboard.TargetName="ScrollViewer"&gt;
                  &lt;EasingThicknessKeyFrame KeyTime="0" Value="0,2,0,0"/&gt;
                  &lt;EasingThicknessKeyFrame KeyTime="0:0:1" Value="200,2,0,0"/&gt;
              &lt;/ThicknessAnimationUsingKeyFrames&gt;
          &lt;/Storyboard&gt;
  
          &lt;Storyboard x:Key="Storyboard2" SpeedRatio="3"&gt;
              &lt;ThicknessAnimationUsingKeyFrames Storyboard.TargetProperty="(FrameworkElement.Margin)" 
                             Storyboard.TargetName="ScrollViewer"&gt;
                  &lt;EasingThicknessKeyFrame KeyTime="0" Value="200,2,0,0"/&gt;
                  &lt;EasingThicknessKeyFrame KeyTime="0:0:1" Value="0,2,0,0"/&gt;
              &lt;/ThicknessAnimationUsingKeyFrames&gt;
          &lt;/Storyboard&gt;
  
      &lt;/ResourceDictionary&gt;
  &lt;/Window.Resources&gt;
  
  &lt;Grid Background="White"&gt;
      &lt;Grid.RowDefinitions&gt;
          &lt;RowDefiniton/&gt;
          &lt;RowDefiniton/&gt;
      &lt;/Grid.RowDefinitions&gt;
      &lt;ToggleButton Width="44" Height="34"
                    Margin="8, 0, 0, 0"
                    HorizontalAlignment="Left"
                    IsChecked="{Binding IsMenuOpen}"
                    IsEnabled="{Binding IsLoggedIn}"&gt;
          &lt;ToggleButton.Style&gt;
              &lt;Style&gt;
                  &lt;Setter Property="ToggleButton.Background"&gt;
                      &lt;Setter.Value&gt;
                          &lt;ImageBrush ImageSource="Skins/Images/btn-top-menu.png"/&gt;
                  &lt;/Setter.Value&gt;
                  &lt;/Setter&gt;
              &lt;/Style&gt;
              &lt;/ToggleButton.Style&gt;
          &lt;ToggleButton.Template&gt;
              &lt;ControlTemplate TargetType="{x:Type ToggleButton}"&gt;
                  &lt;Border CornerRadius="3" Background="{TemplateBinding Background}"&gt;
                      &lt;ContentPresenter Margin="3"
                                      HorizontalAlignment="Center"
                                      VerticalAlignment="Center"/&gt;
                  &lt;/Border&gt;
                  &lt;ControlTemplate.Triggers&gt;
                      &lt;Trigger Property="IsMouseOver" Value="True"&gt;
                          &lt;Setter Property="Background"&gt;
                              &lt;Setter.Value&gt;
                                  &lt;ImageBrush ImageSource="Skins/Images/btn-top-menu-hover.png"/&gt;
                              &lt;/Setter.Value&gt;
                          &lt;/Setter&gt;
                      &lt;/Trigger&gt;
                      &lt;Trigger Property="IsChecked" Value="True"&gt;
                          &lt;Trigger.EnterActions&gt;
                              &lt;BeginStoryboard Storyboard="{StaticResource Storyboard1}"/&gt;
                          &lt;/Trigger.EnterActions&gt;
                          &lt;Trigger.ExitActions&gt;
                              &lt;BeginStoryboard Storyboard="{StaticResource Storyboard2}"/&gt;
                          &lt;/Trigger.ExitActions&gt;
                      &lt;/Trigger&gt;
                  &lt;/ControlTemplate.Triggers&gt;
              &lt;/ControlTemplate&gt;
          &lt;/ToggleButton.Template&gt;
      &lt;/ToggleButton&gt;
  
      &lt;ScrollViewer x:Name="ScrollViewer" Grid.Row="1"
          Margin="0, 2, 0, 0"
          HorizontalScrollBarVisibility="Disabled"
          VerticalScrollBarVisibility="Auto"&gt;
          &lt;Grid&gt;
              &lt;ContentControl Content="{Binding CurrentPageViewModel}"/&gt;
          &lt;/Grid&gt;
      &lt;/ScrollViewer&gt;
  &lt;/Grid&gt;
  &lt;/Window&gt;
  </code></pre>