Remove GridViewCell border when Grouped

[steven]

How do I remove the GridViewCell bottom border when a grouping is selected? I set the default GridViewCell to have a bottom border. When a user selects a grouping I want to remove that border. I tried to add an ExpandedStateGroup to the VisualStateManager of GridViewCellTemplate and remove the border but it didn't work: 

 

<ControlTemplate x:Key="GridViewCellTemplate" TargetType="grid:GridViewCell">
    <Grid>
        <VisualStateManager.VisualStateGroups>
            <VisualStateGroup x:Name="SelectionStates">
                <VisualState x:Name="Unselected"/>
                <VisualState x:Name="Selected"/>
            </VisualStateGroup>
            <VisualStateGroup x:Name="CommonStates">
                <VisualState x:Name="Normal"/>
                <VisualState x:Name="MouseOver">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="Background_Over" Storyboard.TargetProperty="Visibility">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Visibility>Visible</Visibility>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
            </VisualStateGroup>
            <VisualStateGroup x:Name="EditingStates">
                <VisualState x:Name="Edited">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="PART_ContentPresenter" Storyboard.TargetProperty="Margin">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Thickness>0</Thickness>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="PART_ContentPresenter" Storyboard.TargetProperty="VerticalAlignment">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <VerticalAlignment>Stretch</VerticalAlignment>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="PART_CellBorder" Storyboard.TargetProperty="Background">
                            <DiscreteObjectKeyFrame KeyTime="0:0:0" Value="{telerik:Windows8Resource ResourceKey=MainBrush}"/>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
                <VisualState x:Name="Display"/>
            </VisualStateGroup>
            <VisualStateGroup x:Name="DisabledStates">
                <VisualState x:Name="Enabled"/>
                <VisualState x:Name="Disabled">
                    <Storyboard>
                        <DoubleAnimationUsingKeyFrames Storyboard.TargetName="PART_ContentPresenter" Storyboard.TargetProperty="Opacity">
                            <DiscreteDoubleKeyFrame KeyTime="0:0:0" Value="0.3"/>
                        </DoubleAnimationUsingKeyFrames>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="Background_Disabled" Storyboard.TargetProperty="Visibility">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Visibility>Visible</Visibility>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
            </VisualStateGroup>
            <VisualStateGroup x:Name="ValueStates">
                <VisualState x:Name="CellValid"/>
                <VisualState x:Name="CellInvalid">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="Background_Invalid" Storyboard.TargetProperty="Visibility">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Visibility>Visible</Visibility>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
                <VisualState x:Name="CellInvalidUnfocused">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="Background_Invalid_Unfocused" Storyboard.TargetProperty="Visibility">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Visibility>Visible</Visibility>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
            </VisualStateGroup>
            <VisualStateGroup x:Name="ExpandStateGroup">
                <VisualState x:Name="Expanded">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="PART_CellBorder" Storyboard.TargetProperty="BorderThickness">
                            <DiscreteObjectKeyFrame KeyTime="00:00:00">
                                <DiscreteObjectKeyFrame.Value>
                                    <Thickness>0</Thickness>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
                <VisualState x:Name="Collapsed"/>
            </VisualStateGroup>
        </VisualStateManager.VisualStateGroups>
        <Border x:Name="PART_CellBorder"
                Background="{Binding Background, RelativeSource={RelativeSource TemplatedParent}}"
                BorderBrush="{TemplateBinding VerticalGridLinesBrush}"
                BorderThickness="{Binding VerticalGridLinesWidth, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource GridLineWidthToThicknessConverter}, ConverterParameter=Right}"/>
        <Border x:Name="Background_Over"
                Background="{telerik:Windows8Resource ResourceKey=StrongBrush}"
                Opacity="0.15"
                BorderBrush="{TemplateBinding VerticalGridLinesBrush}"
                BorderThickness="{Binding VerticalGridLinesWidth, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource GridLineWidthToThicknessConverter}, ConverterParameter=Right}"
                Grid.Column="2"
                Grid.ColumnSpan="2"
                Visibility="Collapsed"/>
        <Border x:Name="Background_Selected"
                Background="{telerik:Windows8Resource ResourceKey=BasicBrush}"
                BorderBrush="{TemplateBinding VerticalGridLinesBrush}"
                BorderThickness="{Binding VerticalGridLinesWidth, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource GridLineWidthToThicknessConverter}, ConverterParameter=Right}"
                Grid.Column="2"
                Grid.ColumnSpan="2"
                Visibility="Collapsed"/>
        <Border x:Name="Background_Invalid_Unfocused"
                Visibility="Collapsed"
                BorderThickness="1"
                BorderBrush="{telerik:Windows8Resource ResourceKey=ValidationBrush}"
                Grid.Column="2"
                Grid.ColumnSpan="2"
                Opacity="1"/>
        <Border x:Name="Background_Invalid"
                Background="{telerik:Windows8Resource ResourceKey=MainBrush}"
                BorderThickness="1"
                BorderBrush="{telerik:Windows8Resource ResourceKey=ValidationBrush}"
                Grid.Column="2"
                Grid.ColumnSpan="2"
                Visibility="Collapsed">
            <ToolTipService.ToolTip>
                <ToolTip x:Name="validationTooltip" Placement="Right" Content="{TemplateBinding Errors}" Template="{StaticResource GridViewCell_ValidationToolTipTemplate}"/>
            </ToolTipService.ToolTip>
            <Grid Height="22" HorizontalAlignment="Right" VerticalAlignment="Top" Width="22" Background="Transparent">
                <Path
                        Data="M0,0 L4,0 L4,4 z"
                        Fill="{telerik:Windows8Resource ResourceKey=ValidationBrush}"
                        Stretch="Fill"
                        Margin="0,1,1,0"
                        Height="4"
                        VerticalAlignment="Top"
                        HorizontalAlignment="Right"
                        Width="4"/>
            </Grid>
        </Border>
        <Border x:Name="Background_Disabled" Background="{telerik:Windows8Resource ResourceKey=MainBrush}" Opacity="0.3" Grid.Column="2" Grid.ColumnSpan="2" Visibility="Collapsed"/>
        <ContentPresenter x:Name="PART_ContentPresenter"
                Margin="{TemplateBinding Padding}"
                Content="{TemplateBinding Content}"
                ContentTemplate="{TemplateBinding ContentTemplate}"
                VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"/>
    </Grid>
</ControlTemplate>
<Style x:Key="GridViewCellStyle" TargetType="grid:GridViewCell">
    <Setter Property="Template" Value="{StaticResource GridViewCellTemplate}"/>
    <Setter Property="BorderBrush" Value="{telerik:Windows8Resource ResourceKey=BasicBrush}"/>
    <Setter Property="Padding" Value="5,0,3,0"/>
    <Setter Property="BorderThickness" Value="0,0,1,0"/>
    <Setter Property="VerticalContentAlignment" Value="Center"/>
    <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="SnapsToDevicePixels" Value="True"/>
    <Setter Property="FocusVisualStyle" Value="{StaticResource FocusVisualStyle}"/>
</Style>

[Dimitrina]

Hello,

When RadGridView is grouped you can apply a new cell style targeting all GridViewCells. Then, on removing grouping you should set back the default style.
You can subscribe to the Grouping event to know when grouping action occurs.

Regards,
Dimitrina
Telerik