How to change ListView Header text alignment (when already styled with a DynamicResource)

Question

I'm not very good with WPF and, sometimes, I need to change some settings of programs components I didn't develope.

I want to change a ListView headers from centered to left but this ListView is already styled with the property Style="{DynamicResource ListViewStyle}".

This is the ListViewStyle definition:

    <Style x:Key="ListViewStyle"
           TargetType="{x:Type ListView}">
        <Setter Property="SnapsToDevicePixels" Value="true"/>
        <Setter Property="OverridesDefaultStyle" Value="true"/>
        <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto"/>
        <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
        <Setter Property="ScrollViewer.CanContentScroll" Value="true"/>
        <Setter Property="VerticalContentAlignment" Value="Center"/>
        <Setter Property="Background" Value="#121E34"/>
        <Setter Property="FontFamily" Value="{DynamicResource Roboto}"/>
        <Setter Property="FontSize" Value="{DynamicResource FontSize30pt}"/>

        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ListView}">
                    <Border x:Name="Border"
                            BorderThickness="0">
                        <ScrollViewer Style="{DynamicResource ScrollViewerStyle}">
                            <ItemsPresenter/>
                        </ScrollViewer>
                    </Border>

                    <ControlTemplate.Triggers>
                        <Trigger Property="IsGrouping" Value="true">
                            <Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
                            <Setter Property="Foreground" Value="green"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>

        <Setter Property="Background" Value="#121E34"/>
    </Style>

and the ScrollViewerStyle definition is:

    <Style x:Key="ScrollViewerStyle"
           TargetType="{x:Type ScrollViewer}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ScrollViewer}">
                    <Grid>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="*"/>
                            <ColumnDefinition Width="Auto"/>
                        </Grid.ColumnDefinitions>

                        <Grid.RowDefinitions>
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="Auto"/>
                        </Grid.RowDefinitions>

                        <Rectangle Style="{DynamicResource RectangleScrittura}"/>

                        <DockPanel>
                            <ScrollViewer Height="60"
                                          Background="#121E34"
                                          DockPanel.Dock="Top"
                                          Focusable="false"
                                          Foreground="#FFFFFF"
                                          HorizontalScrollBarVisibility="Hidden"
                                          VerticalScrollBarVisibility="Hidden">
                                <GridViewHeaderRowPresenter Height="62"
                                                            Margin="10,0"
                                                            AllowsColumnReorder="{Binding TemplatedParent.View.AllowsColumnReorder, RelativeSource={RelativeSource TemplatedParent}}"
                                                            ColumnHeaderContainerStyle="{Binding TemplatedParent.View.ColumnHeaderContainerStyle, RelativeSource={RelativeSource TemplatedParent}}"
                                                            ColumnHeaderContextMenu="{Binding TemplatedParent.View.ColumnHeaderContextMenu, RelativeSource={RelativeSource TemplatedParent}}"
                                                            ColumnHeaderTemplate="{Binding TemplatedParent.View.ColumnHeaderTemplate, RelativeSource={RelativeSource TemplatedParent}}"
                                                            ColumnHeaderTemplateSelector="{Binding TemplatedParent.View.ColumnHeaderTemplateSelector, RelativeSource={RelativeSource TemplatedParent}}"
                                                            ColumnHeaderToolTip="{Binding TemplatedParent.View.ColumnHeaderToolTip, RelativeSource={RelativeSource TemplatedParent}}"
                                                            Columns="{Binding TemplatedParent.View.Columns, RelativeSource={RelativeSource TemplatedParent}}"
                                                            OpacityMask="{x:Null}"
                                                            SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
                                                            TextBlock.FontFamily="{DynamicResource Roboto}"
                                                            Visibility="{Binding TemplatedParent.Visibility, RelativeSource={RelativeSource TemplatedParent}}">
                                </GridViewHeaderRowPresenter>
                            </ScrollViewer>

                            <ScrollContentPresenter x:Name="PART_ScrollContentPresenter"
                                                    CanContentScroll="True"
                                                    CanHorizontallyScroll="False"
                                                    CanVerticallyScroll="False"
                                                    KeyboardNavigation.DirectionalNavigation="Local">
                            </ScrollContentPresenter>
                        </DockPanel>

                        <ScrollBar x:Name="PART_VerticalScrollBar"
                                   Grid.Column="1"
                                   Width="40"
                                   Margin="5,0,0,0"
                                   BorderThickness="0"
                                   Maximum="{TemplateBinding ScrollableHeight}"
                                   Template="{DynamicResource ScrollBarTemplate}"
                                   ViewportSize="{TemplateBinding ViewportHeight}"
                                   Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}"
                                   Value="{TemplateBinding VerticalOffset}">
                        </ScrollBar>

                        <ScrollBar x:Name="PART_HorizontalScrollBar"
                                   Grid.Row="1"
                                   Width="Auto"
                                   Height="40"
                                   Margin="0,5,0,0"
                                   BorderThickness="0"
                                   Maximum="{TemplateBinding ScrollableWidth}"
                                   Template="{DynamicResource ScrollBarTemplateHorizontal}"
                                   ViewportSize="{TemplateBinding ViewportWidth}"
                                   Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}"
                                   Value="{TemplateBinding HorizontalOffset}">
                        </ScrollBar>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

I've tried to change the ListView HorizontalContentAlignment with the code below but it resets the header to the default style:

<Style TargetType="{x:Type GridViewColumnHeader}">
    <Setter Property="HorizontalContentAlignment" Value="Left" />
</Style>

What should I do?

Answer 1

I found an easy solution to my problem: adding HorizontalAlignment="Left" inside the GridViewHeaderRowPresenter tag of the ScrollViewerStyle definition did the trick.

<GridViewHeaderRowPresenter Height="62"
                        Margin="5,0"
                        HorizontalAlignment="Left"
                        AllowsColumnReorder="{Binding TemplatedParent.View.AllowsColumnReorder, RelativeSource={RelativeSource TemplatedParent}}"
                        ColumnHeaderContainerStyle="{Binding TemplatedParent.View.ColumnHeaderContainerStyle, RelativeSource={RelativeSource TemplatedParent}}"
                        ColumnHeaderContextMenu="{Binding TemplatedParent.View.ColumnHeaderContextMenu, RelativeSource={RelativeSource TemplatedParent}}"
                        ColumnHeaderTemplate="{Binding TemplatedParent.View.ColumnHeaderTemplate, RelativeSource={RelativeSource TemplatedParent}}"
                        ColumnHeaderTemplateSelector="{Binding TemplatedParent.View.ColumnHeaderTemplateSelector, RelativeSource={RelativeSource TemplatedParent}}"
                        ColumnHeaderToolTip="{Binding TemplatedParent.View.ColumnHeaderToolTip, RelativeSource={RelativeSource TemplatedParent}}"
                        Columns="{Binding TemplatedParent.View.Columns, RelativeSource={RelativeSource TemplatedParent}}"
                        OpacityMask="{x:Null}"
                        SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
                        TextBlock.FontFamily="{DynamicResource Roboto}"
                        Visibility="{Binding TemplatedParent.Visibility, RelativeSource={RelativeSource TemplatedParent}}">

Thanks to everyone!