title: WPF ScrollViewer is not appears in my Window after I add it
body: <p>I have a MainWindow which includes 2 Dock Panels, a Grid (in the right Dock Panel) and inside of it some User Controls.<br>
  I want to add a ScrollViewer to appears in the right of my MainWindow, because I have a lot of content in each User Control.</p>
  
  <p>When I'm add these 2 parameters to my XAML, I'm still didn't see the ScrollViewer appears, and I tried to write it under the Window, Grid, DockPanel, but nothing works.</p>
  
  <pre><code>ScrollViewer.VerticalScrollBarVisibility="Visible" ScrollViewer.CanContentScroll="True"
  </code></pre>
  
  <p>What I'm doing wrong?<br>
  Thank you for your help.</p>
  
  <p><strong>MainWindow.xaml</strong></p>
  
  <pre><code>&lt;Grid ScrollViewer.VerticalScrollBarVisibility="Visible"
         ScrollViewer.CanContentScroll="True"&gt;
      &lt;Grid.ColumnDefinitions&gt;
          &lt;ColumnDefinition Width="auto" /&gt;
          &lt;ColumnDefinition Width="auto" /&gt;
      &lt;/Grid.ColumnDefinitions&gt;
      &lt;DockPanel&gt;
          &lt;Border DockPanel.Dock="Left" BorderBrush="Black" BorderThickness="0,0,1,0"
                      Height="700"&gt;
              &lt;StackPanel &gt;
                  &lt;TextBlock Name="TextBlock_RegularUnit" Text="Regular Unit" 
                   HorizontalAlignment="Center" MouseEnter="TextBox_RegularUnit_MouseEnter"
                   MouseLeave="TextBox_RegularUnit_MouseLeave" /&gt;
              &lt;/StackPanel&gt;
          &lt;/Border&gt;
      &lt;/DockPanel&gt;
      &lt;DockPanel Name="DockPanel_UnitStatusReport" Grid.Column="1" Visibility="Visible"&gt;
          &lt;Grid ShowGridLines="False"&gt;
              &lt;Grid.RowDefinitions&gt;
                  &lt;RowDefinition Height="auto" /&gt;
                  &lt;RowDefinition Height="auto" /&gt;
                  &lt;RowDefinition Height="auto" /&gt;
              &lt;/Grid.RowDefinitions&gt;
              &lt;local:ManageUsers x:Name="ucManageUsers" Visibility="Hidden" /&gt;
              &lt;local:RegularUnit x:Name="ucRegularUnit" Grid.Row="0" /&gt;
              &lt;local:Actions x:Name="ucActions" Grid.Row="1"/&gt;
              &lt;local:HistoryTable x:Name="ucHistoryTable" Grid.Row="2"/&gt;
          &lt;/Grid&gt;
      &lt;/DockPanel&gt;
  &lt;/Grid&gt;
  </code></pre>