Use of Commands, Expander in WPF

This is for xaml file designer :----

Window x:Class="WpfApplication1.Window2"

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        Title="Window2" WindowState="Normal" Width="250">

    <Window.CommandBindings>

        <CommandBinding Command="New"  Executed="CommandBinding_Executed_1"  CanExecute="CommandBinding_CanExecute_1">

            

        </CommandBinding>

    </Window.CommandBindings>

    <ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto" >

    <Grid Width="200" HorizontalAlignment="Center">

        <WrapPanel ScrollViewer.CanContentScroll="True" ScrollViewer.VerticalScrollBarVisibility="Visible" ScrollViewer.PanningRatio="5" ScrollViewer.PanningMode="VerticalOnly" ScrollViewer.IsDeferredScrollingEnabled="True">

            <StackPanel>

            <TextBlock TextWrapping="Wrap">You can use a Popup to provide a link for a specific <Run TextDecorations="Underline" MouseEnter="run_MouseEnter">term</Run> of interest.</TextBlock>

            <Popup Name="popLink" StaysOpen="False" Placement="Mouse" MaxWidth="200" PopupAnimation="Fade"  AllowsTransparency="True">

                <Border BorderBrush="Beige" BorderThickness="2" Background="White">

                    <TextBlock Margin="10" TextWrapping="Wrap">      For more information, see      <Hyperlink NavigateUri="http://en.wikipedia.org/wiki/Term" Click="lnk_Click">Wikipedia</Hyperlink></TextBlock>

                </Border>

            </Popup>

            <Expander Margin="5" Padding="5" Header="Region One">

                <Button Padding="3">Hidden Button One</Button>

            </Expander>

            <Expander Margin="5" Padding="5" Header="Region Two" >

                <TextBlock TextWrapping="Wrap">      Lorem ipsum dolor sit amet, consectetuer adipiscing elit ...</TextBlock>

            </Expander>

            <Expander Margin="5" Padding="5" Header="Region Three">

                <Button Padding="3" Height="30" Width="150" Click="Button_Click_2">Hidden Button Two</Button>

            </Expander>

            <Expander Margin="5" Header="Name" Padding="5" BorderBrush="White" Background="DimGray">

                <StackPanel>

                <TextBlock TextWrapping="Wrap" Padding="5" >Himanshu</TextBlock>

                <Button Command="New" Height="20" Width="150" Click="Button_Click_1" >

                    NEW

                </Button>

                </StackPanel>

            </Expander>

    

        </StackPanel>

        </WrapPanel>

    </Grid>

    </ScrollViewer>

</Window>

This code to write in cs file:---

private void CommandBinding_Executed_1(object sender, ExecutedRoutedEventArgs e)

        {

            MessageBox.Show("Use of Commands");

        }

 

        

        private void CommandBinding_CanExecute_1(object sender, CanExecuteRoutedEventArgs e)

        {

            if (isDirty == true)

            {

                e.CanExecute = isDirty;

            }

            

        }

        private void Button_Click_2(object sender, RoutedEventArgs e)

        {

            isDirty = true;

        }