Encrypting a dataset using AES, including compression

<Window x:Class="MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Encrypt dataset" 
        Height="350" 
        Width="525" 
        Closing="Window_Closing" 
        Icon="/EncryptDataSetVB;component/Images/Data.png" WindowStartupLocation="CenterScreen">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition />
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <GroupBox Grid.Row="0" Name="gbDataset" Header="Define dataset">
            <StackPanel Orientation="Horizontal" Margin="3">
                <CheckBox Name="chkCompress" Margin="3,3,15,3" Content="Use compressed file" VerticalAlignment="Center" />
                <Button Margin="3" Click="btnCreate_Click" Content="Create a new dataset..."/>
                <Button Margin="3" Click="btnOpen_Click" Content="Open dataset..."/>
            </StackPanel>
        </GroupBox>
        <GroupBox Grid.Row="1" Name="gbData" Header="Current dataset: None" Padding="3">
            <DataGrid Name="dgContacts" AutoGenerateColumns="False" ItemsSource="{Binding}">
                <DataGrid.Columns>
                    <DataGridTextColumn Header="First name" Binding="{Binding Path=FirstName}"  />
                    <DataGridTextColumn Header="Last name" Binding="{Binding Path=LastName}"  />
                    <DataGridTextColumn Header="Telephone" Binding="{Binding Path=Telephone}"  />
                    <DataGridTextColumn Header="E-mail" Binding="{Binding Path=Email}"  />
                </DataGrid.Columns>
            </DataGrid>
        </GroupBox>
        <GroupBox Grid.Row="2" Name="gbActions" >
            <StackPanel Orientation="Horizontal" Margin="3" HorizontalAlignment="Right">
                <Button Margin="3" Name="btnSave" Click="btnSave_Click" Content="Save changes" IsEnabled="False" />
                <Button Margin="3" Name="btnCancel" Click="btnCancel_Click" Content="Cancel changes" IsEnabled="False" />
            </StackPanel>
        </GroupBox>
    </Grid>
</Window>