TextBlock滚动条

<ScrollViewer Name="scrollViewer">
            <TextBlock TextWrapping="Wrap" ScrollViewer.VerticalScrollBarVisibility="Auto" Name="txtContent"  HorizontalAlignment="Stretch" VerticalAlignment="Stretch" ></TextBlock>
        </ScrollViewer>

<ScrollViewer VerticalScrollBarVisibility="Auto" MaxHeight="90" Width="130">
                                        <TextBlock Margin="0 5 0 5" TextWrapping="Wrap" Name="txtAddress"></TextBlock>
                                    </ScrollViewer>