How to prevent Popup losing focus?

Question

I have a Combobox defined in a data template of an ItemsControl. This ComboBox has a Button defined in it. On the Button_Click event, a Popup should be shown. This Popup contain a custom UserControl that has some controls defined inside it.

Here is the code before I explain my problem:

<ComboBox x:Name="cb" HorizontalAlignment="Center" Grid.Column="2" Width="140" Visibility="{Binding HasCombobox, Converter={StaticResource BoolToVis}}">
    <ComboBox.ItemsSource>
       <CompositeCollection>
           <CollectionContainer Collection="{Binding Source={StaticResource cvs}}" />
           <ComboBoxItem>
              <Button Click="Button_Click" Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}" Content="{x:Static prop:Resources.INSERT_BTN}"/>
           </ComboBoxItem>
       </CompositeCollection>
    </ComboBox.ItemsSource>
</ComboBox>

This is the Button_Click event:

private void Button_Click(object sender, RoutedEventArgs e)
{
    Button s = sender as Button;
    var popup = new System.Windows.Controls.Primitives.Popup();
    popup.AllowsTransparency = true;
    popup.Child = new myCustomView();
    popup.PlacementTarget = s;
    popup.Placement = System.Windows.Controls.Primitives.PlacementMode.Top;
    popup.IsOpen = true;
    popup.StaysOpen = true;
}

The problem is that when I click any of the controls defined inside myCustomView the Popup loses the focus and closes. How can I force it to stay opened?

EDIT 1 :

Since myCustomView has its own ViewModel I tried to hack the Popup to stay open by binding its IsOpen property to a boolean inside the view model like this:

popup.DataContext = myCustomViewModel;
Binding b = new Binding();
b.Source = myCustomViewModel;
b.Path = new PropertyPath("stayOpened");
b.Mode = BindingMode.TwoWay;
b.UpdateSourceTrigger = UpdateSourceTrigger.Default;
BindingOperations.SetBinding(popup, Popup.IsOpenProperty, b);
// BindingOperations.SetBinding(popup, Popup.StaysOpenProperty, b);  tried both IsOpened and StaysOpen

But the focus switch still kills my Popup.

Answer 1

You could set the PlacementTarget to the parent ItemsControl and then set the VerticalOffset and HorizontalOffset properties of the Popup to specify its exact location on the screen, e.g.:

private void btn_Click(object sender, RoutedEventArgs e)
{
    Button s = sender as Button;
    System.Windows.Controls.Primitives.Popup popup = new System.Windows.Controls.Primitives.Popup();
    popup.AllowsTransparency = true;
    popup.Child = new myCustomView();
    //some stuff needed to recognise which button was pressed
    popup.PlacementTarget = ic; //<-- "ic" is the name of the parent ItemsControl
    Point p = s.TranslatePoint(new Point(0, 0), ic);
    popup.VerticalOffset = p.Y; //adjust this value to fit your requirements
    popup.HorizontalOffset = p.X; //adjust this value to fit your requirements
    popup.IsOpen = true;
    popup.StaysOpen = true;
}

Answer 2

You could set Popup.StaysOpen to true like this

<Popup StaysOpen="True"/>