windows phone panaroma隐藏控件之后selectionchanged会出现此控件闪动消失的问题

使用panaroma控件，

 <controls:PanoramaItem Foreground="{StaticResource MainTitle}" Header="我的帐号">
                <Grid Height="650" Margin="12,0,0,0" VerticalAlignment="Top">

                    <Grid x:Name="userHomeLogined" Visibility="Collapsed">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="150"></RowDefinition>
                            <RowDefinition Height="*"></RowDefinition>
                        </Grid.RowDefinitions>
                        <Grid Grid.Row="0">
                            <StackPanel Orientation="Horizontal">
                                <Image Stretch="None" Source="/Image/UserHome/uploadphoto.png"></Image>
                                <TextBlock Margin="0,12,0,0" Text="某个用户"></TextBlock>
                            </StackPanel>
                        </Grid>
                        <ListBox x:Name="userHomeMenu" Grid.Row="1">
                            <ListBoxItem>
                                <StackPanel Height="40" Orientation="Horizontal">
                                    <Image Source="/Image/userhome/collection.png"></Image>
                                    <TextBlock x:Name="accountRemain" Tap="accountRemain_Tap" Margin="12,0,0,0"  Foreground="{StaticResource HubBackground}" Text="我的余额"></TextBlock>
                                </StackPanel>
                            </ListBoxItem>
                        </ListBox>
                    </Grid>
                    <StackPanel x:Name="userHomeUnLogin" Orientation="Vertical">
                        <TextBlock Text="用户名/邮箱/会员帐号"></TextBlock>

                        <TextBox BorderThickness="1" BorderBrush="Gray" Width="400" Style="{StaticResource TextBoxStyle1}">
                        </TextBox>
                        <TextBlock Text="密码"></TextBlock>
                        <TextBox  BorderThickness="1" BorderBrush="Gray"  Width="400" Style="{StaticResource TextBoxStyle1}">
                        </TextBox>
                        <Button x:Name="login" Click="login_Click" Width="200" Height="100" Background="{StaticResource HubBackground}" Content="登录" Style="{StaticResource ButtonStyle1}"></Button>

                        <HyperlinkButton Foreground="{StaticResource HubBackground}" Content="如果没有帐号,请点击这里注册" Name="register" />
                    </StackPanel>
                </Grid>

            </controls:PanoramaItem>

我要在用户点击登录之后将userHomeUnLogin隐藏，将userHomeLogined显示，如果使用

 

userHomeUnLogin.Visibility = System.Windows.Visibility.Collapsed;
userHomeLogined.Visibility = System.Windows.Visibility.Visible;

在拖动panaroma之后，userHomeUnLogin还会闪动一下，然后消失，

解决方案

    userHomeUnLogin..Children.Clear();
            userHomeLogined.Visibility = System.Windows.Visibility.Visible;