Selection text disappears when contextmenu pops up

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C#

WPF

menu

selection

Greetings All,
I am getting some weird behavior from WPF when i create an event to programatically open a context menu. once I select a text and right click the highlight of the selection disappears once the context menu opens up.
Here is a sample of the problem:

Xaml:

<Window x:Class="WpfApplication19.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="287" Width="419">
    <Grid>
        <TextBox x:Name="myText" Height="38" Margin="0,72,6,0" VerticalAlignment="Top" HorizontalAlignment="Right" Width="135"></TextBox>
        <Label Height="30" Margin="12,80,164,0" Name="label1" VerticalAlignment="Top">Textbox with contextMenu property set</Label>
        <Label Height="30" Margin="12,0,136,91" Name="label2" VerticalAlignment="Bottom">TextBox Open ContextMenu by programmatically</Label>
        <TextBox Height="38" Margin="0,0,6,81" x:Name="myText1" VerticalAlignment="Bottom" HorizontalAlignment="Right" Width="135" />
    </Grid>
</Window>

And Code Behind:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication19
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>
    public partial class Window1 : Window
    {
        ContextMenu con = new ContextMenu();
        public Window1()
        {
            InitializeComponent();
            MenuItem menuItem1 = new MenuItem();
            menuItem1.Header = "Menu1";
            MenuItem menuItem2 = new MenuItem();
            menuItem2.Header = "Menu2";

            con.Items.Add(menuItem1);
            con.Items.Add(menuItem2);

            this.myText.ContextMenu = con;

            this.myText1.PreviewMouseDown += new MouseButtonEventHandler(myText1_PreviewMouseDown);

        }




        void myText1_PreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            base.OnPreviewMouseDown(e);
            if (e.RightButton == MouseButtonState.Pressed)
            {
               con.Placement = System.Windows.Controls.Primitives.PlacementMode.MousePoint;

                con.IsOpen = true;
                IInputElement focusedElement = FocusManager.GetFocusedElement(this);


            }
        }



    }
}

Thank You in advance!