Remebering State of Expand/Collapse of all the groups in ListView WPF

Question

I have a ListView and implemented Grouping with the code below in XAML,

       <ListView.GroupStyle>
                        <GroupStyle>
                            <GroupStyle.ContainerStyle>
                                <Style TargetType="{x:Type GroupItem}">
                                    <Setter Property="Margin" Value="0,0,0,0"/>
                                    <Setter Property="Template">
                                        <Setter.Value>
                                            <ControlTemplate TargetType="{x:Type GroupItem}">
                                                <Expander x:Name="Exp"  IsExpanded="{Binding Path=Items[0].IsExpanded,Mode=TwoWay}"  BorderBrush="#FFCCCCCC" Background="White"
                        BorderThickness="0,0,0,1">
                                                    <Expander.Header>
                                                        <DockPanel>
                                                            <TextBlock>
                                                                <TextBlock FontWeight="Bold" Text="{Binding Path=Name}" 
                               Margin="5,0,0,0" Width="Auto"/><Run Text=" ("/><TextBlock FontWeight="Bold" Text="{Binding Path=ItemCount}"/><Run Text=")"/></TextBlock>
                                                        </DockPanel>
                                                    </Expander.Header>
                                                    <Expander.Content>
                                                        <ItemsPresenter />
                                                    </Expander.Content>
                                                </Expander>
                                            </ControlTemplate>
                                        </Setter.Value>
                                    </Setter>
                                </Style>
                            </GroupStyle.ContainerStyle>
                        </GroupStyle>
                    </ListView.GroupStyle>

The Expand/Collapse is working fine.But, I want to save the the Group State onExit and load the application, in the same state the nxt LogIn. I am saving all the preferences in xml file.

Any Suggestions Please.