删除ListPicker中的线条或使用样式隐藏它们

<Style x:Key="CustomListPickerStyle" TargetType="toolkit:ListPicker">
    <Setter Property="BorderThickness" Value="0"/>
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="Foreground" Value="{StaticResource PhoneForegroundBrush}"/>
    <Setter Property="FullModeItemContainerStyle" Value="{StaticResource FullModeItemContainerStyle}"/>
    <Setter Property="HorizontalContentAlignment" Value="Left"/>
    <Setter Property="ItemContainerStyle" Value="{StaticResource ItemContainerStyle}"/>
    <Setter Property="ItemTemplate" Value="{StaticResource ItemTemplate}"/>
    <Setter Property="Margin" Value="{StaticResource PhoneTouchTargetOverhang}"/>
    <Setter Property="VerticalContentAlignment" Value="Top"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="toolkit:ListPicker">
                <Grid>
                    <!-- ListPicker的其他部分 -->
                    <!-- ... -->
                    <Border x:Name="Border" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                        <Grid>
                            <ContentControl x:Name="ContentPresenter" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="0" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
                            <Popup x:Name="FullModePopup">
                                <!-- FullModePopup的内容 -->
                                <!-- ... -->
                            </Popup>
                        </Grid>
                    </Border>
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>