WPF Expander ExpandDirection Left,Right,Up,Down,IsExpanded property,Expanded and Collapsed event

//xaml
<Window x:Class="WpfApp378.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:local="clr-namespace:WpfApp378"
        mc:Ignorable="d" WindowState="Maximized"
        Title="MainWindow" Height="450" Width="800">
    <Grid ShowGridLines="True">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="500"/>
            <ColumnDefinition/>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <Expander Header="Gramma Left" IsExpanded="True" 
                  Expanded="Expander_Expanded"
                  Collapsed="Expander_Collapsed"
                  ExpandDirection="Left" Grid.Column="0" Grid.Row="0">
            <StackPanel>
                <CheckBox>Check gramma as you type.</CheckBox>
                <CheckBox>Hide grammatical errors in this document.</CheckBox>
                <CheckBox>Check gramma with spelling.</CheckBox>
            </StackPanel>
        </Expander>
        <Expander Header="Gramma Right" ExpandDirection="Right" Grid.Column="0" Grid.Row="1">
            <StackPanel>
                <CheckBox>Check gramma as you type.</CheckBox>
                <CheckBox>Hide grammatical errors in this document.</CheckBox>
                <CheckBox>Check gramma with spelling.</CheckBox>
            </StackPanel>
        </Expander>
        <Expander Header="Gramma Down" ExpandDirection="Down" Grid.Column="0" Grid.Row="2">
            <StackPanel>
                <CheckBox>Check gramma as you type.</CheckBox>
                <CheckBox>Hide grammatical errors in this document.</CheckBox>
                <CheckBox>Check gramma with spelling.</CheckBox>
            </StackPanel>
        </Expander>
        <Expander Header="Gramma Up" ExpandDirection="Up" Grid.Column="0" Grid.Row="3">
            <StackPanel>
                <CheckBox>Check gramma as you type.</CheckBox>
                <CheckBox>Hide grammatical errors in this document.</CheckBox>
                <CheckBox>Check gramma with spelling.</CheckBox>
            </StackPanel>
        </Expander>
    </Grid>
</Window>


//cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
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 WpfApp378
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            //SuppressScriptErrors(webBrowser, true);
        }

        void SuppressScriptErrors(WebBrowser browser, bool hide)
        {
            browser.Navigating += (s, e) =>
            {
                var fiComWebBrowser = typeof(WebBrowser).GetField("_axIWebBrowser2",
                    System.Reflection.BindingFlags.Instance |
                    System.Reflection.BindingFlags.NonPublic);
                if (fiComWebBrowser == null)
                {
                    return;
                }

                object objComBrowser = fiComWebBrowser.GetValue(browser);
                if (objComBrowser == null)
                {
                    return;
                }
                objComBrowser.GetType().InvokeMember("Silent",
                    System.Reflection.BindingFlags.SetProperty,
                    null,
                    objComBrowser, new object[] { hide });
            };
        }

        private void Expander_Expanded(object sender, RoutedEventArgs e)
        {
            MessageBox.Show("Expander will Left Expand!");
        }

        private void Expander_Collapsed(object sender, RoutedEventArgs e)
        {
            MessageBox.Show("Expander will Left Collapse!");
        }
    }
}