请教如何动态在list数据模版中操作Grid里的元素

<phone:LongListSelector x:Name="WordingsList">
                    <phone:LongListSelector.ItemTemplate>
                        <DataTemplate>
                            <Grid Height="62" VerticalAlignment="Top" MouseLeftButtonDown="ListOpen" >
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="20*"/>
                                    <ColumnDefinition Width="140*"/>
                                </Grid.ColumnDefinitions>
                                <TextBlock x:Name="txtWordingsEN" Text="{Binding WordingsEN}" FontWeight="Bold" VerticalAlignment="Center" Margin="20,0" Foreground="Black" Height="30" FontSize="22" Grid.Column="2" Canvas.ZIndex="1" />
                                <TextBlock x:Name="txtWordingsCH" Text="{Binding WordingsCH}" FontWeight="Bold" VerticalAlignment="Bottom" Margin="20,5" Foreground="#FF817A7A" FontSize="26" Grid.Column="2" Height="30" Canvas.ZIndex="1" Visibility="Collapsed" />
                                <Image HorizontalAlignment="Right" Height="20" VerticalAlignment="Center" Width="20" Source="/Images/speaker.png" Canvas.ZIndex="1" Tag="{Binding WordingsName}" MouseLeftButtonDown="Speaker"/>
                                <Image x:Name="ListBackgroundImage" Source="/Images/list.png" Grid.RowSpan="2" Grid.ColumnSpan="2"></Image>
                                <Image Width="20" Height="20" Grid.Column="2" HorizontalAlignment="Right" VerticalAlignment="Center" Margin="20,0" Source="/Images/arrow_down.png"></Image>
                                <Image Width="20" Height="20" Grid.Column="2" HorizontalAlignment="Right" VerticalAlignment="Center" Margin="60,0" Source="/Images/comment.png" Visibility="Collapsed"></Image>