How to display the textbox control on scroll of popup inside a combo box, this is continuation for WPF ComboBox with checkboxes and textbox with search field
Also I would like to display a line gap between text box and the combo box items binded
<Popup
Name="Popup"
Placement="Bottom"
AllowsTransparency="True"
Focusable="False" IsOpen="{TemplateBinding IsDropDownOpen}"
PopupAnimation="Slide">
<Grid
Name="DropDown"
SnapsToDevicePixels="True"
MinWidth="{TemplateBinding ActualWidth}"
MaxHeight="{TemplateBinding MaxDropDownHeight}">
<Border
x:Name="DropDownBorder"
BorderThickness="1" Background="White"
BorderBrush="Black"/>
<ScrollViewer Margin="4,6,4,6" SnapsToDevicePixels="True" DataContext="{Binding}">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<TextBox />
<StackPanel Grid.Row="1" IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
</Grid>
</ScrollViewer>
</Grid>