Is it possible to create some sort of base expander style and override the background color of the header in a derived style?
In my application I'm using expanders a lot and I would like to change the background color of the header. I know I could just copy&paste my style and edit the color, but it would be nicer to just create a new style based on the "base style" and setting the header's background color.
But I do not know how to access this color.
It's the color of this line: below I'd like to change (the border in the header): Border Name="border"... I cannot access "border" in the setter of the derived style...
This is my (base) style:
<Style TargetType="Expander" x:Key="ExpanderStyle">
<Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextColor}}"/>
<Setter Property="Template">
<Setter.Value>
<!-- Control template for expander -->
<ControlTemplate TargetType="Expander" x:Name="exp">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Name="ContentRow" Height="0"/>
</Grid.RowDefinitions>
<Border Name="border" Grid.Row="0" Background="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}" BorderThickness="1" CornerRadius="4,4,0,0" >
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="20" />
</Grid.ColumnDefinitions>
<ToggleButton x:Name="tb" FontFamily="Marlett" FontSize="9.75" Background="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}" Foreground="Black" Grid.Column="1" Content="u" IsChecked="{Binding Path=IsExpanded,Mode=TwoWay,RelativeSource={RelativeSource TemplatedParent}}" />
<ContentPresenter x:Name="HeaderContent" Grid.Column="0" Margin="4" ContentSource="Header" RecognizesAccessKey="True" />
</Grid>
</Border>
<Border x:Name="Content" Grid.Row="1" BorderThickness="1,0,1,1" CornerRadius="0,0,4,4" >
<ContentPresenter Margin="4" />
</Border>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsExpanded" Value="True">
<Setter TargetName="ContentRow" Property="Height" Value="{Binding ElementName=Content,Path=Height}" />
<Setter Property="Content" TargetName="tb" Value="t"></Setter>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
I would like to do something like this:
<Style x:Key="ExpanderStyleRed" BasedOn="{StaticResource ExpanderStyle}" TargetType="Expander">
<Setter Property="???" Value="Red"/>
<Style>
Use TemplateBinding:
<Style TargetType="Expander" x:Key="ExpanderStyle">
<Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextColor}}"/>
<Setter Property="Template">
<Setter.Value>
<!-- Control template for expander -->
<ControlTemplate TargetType="Expander" x:Name="exp">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Name="ContentRow" Height="0"/>
</Grid.RowDefinitions>
<Border Name="border" Grid.Row="0" Background="{TemplateBinding Background}" BorderThickness="1" CornerRadius="4,4,0,0" >
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="20" />
</Grid.ColumnDefinitions>
<ToggleButton x:Name="tb" FontFamily="Marlett" FontSize="9.75" Background="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}" Foreground="Black" Grid.Column="1" Content="u" IsChecked="{Binding Path=IsExpanded,Mode=TwoWay,RelativeSource={RelativeSource TemplatedParent}}" />
<ContentPresenter x:Name="HeaderContent" Grid.Column="0" Margin="4" ContentSource="Header" RecognizesAccessKey="True" />
</Grid>
</Border>
<Border x:Name="Content" Grid.Row="1" BorderThickness="1,0,1,1" CornerRadius="0,0,4,4" >
<ContentPresenter Margin="4" />
</Border>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsExpanded" Value="True">
<Setter TargetName="ContentRow" Property="Height" Value="{Binding ElementName=Content,Path=Height}" />
<Setter Property="Content" TargetName="tb" Value="t"></Setter>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="ExpanderStyleRed" BasedOn="{StaticResource ExpanderStyle}" TargetType="Expander">
<Setter Property="Background" Value="#2fff0000"/>
</Style>
And then:
<Grid>
<Expander x:Name="expander1" Style="{DynamicResource ExpanderStyle}" Header="Expander" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="7,10,0,0" Height="108">
<TextBlock Width="250" Height="150" TextWrapping="Wrap">
asklsaklsa saaskklsaklas alsaklalkjd
asklsaklsaklsa saklsaklsakl jsajkjska
saklsaklsakl sasa
</TextBlock>
</Expander>
<Expander x:Name="expander2" Style="{DynamicResource ExpanderStyleRed}" Header="Expander" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="12,126,0,0" Height="133">
<TextBlock Width="250" Height="150" TextWrapping="Wrap">
asklsaklsa saaskklsaklas alsaklalkjd
asklsaklsaklsa saklsaklsakl jsajkjska
saklsaklsakl sasa
</TextBlock>
</Expander>
</Grid>
Related
Some functions change the value of a TextBlock in the ListView. I want to access TextBlock value at the end of these functions. How can I do it?
ListView code :
<ListView BorderThickness="0" x:Name="OrderList">
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel/>
</ItemsPanelTemplate>
</ListView.ItemsPanel>
<ListView.ItemContainerStyle>
<Style TargetType="{x:Type ListViewItem}">
<Setter Property="Background" Value="Transparent" />
<Setter Property="BorderBrush" Value="Transparent"/>
<Setter Property="VerticalContentAlignment" Value="Center"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ListViewItem}">
<Grid Background="{TemplateBinding Background}">
<Border BorderBrush="{StaticResource MenuluxRedBrush}" BorderThickness="0,0,0,1" Height="30">
<local:OrderPopUpItem/>
</Border>
<GridViewRowPresenter Grid.RowSpan="2"
Margin="{TemplateBinding Padding}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground"
Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ListView.ItemContainerStyle>
</ListView>
OrderPopUpItem.xaml code :
<Grid Background="White">
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBlock Text="{Binding productName}"
VerticalAlignment="Center"
Margin="15,0,0,0"
FontSize="20"/>
<Grid Grid.Column="1">
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Image Source="/Images/PopUp/icon_minus_red.png"
MouseLeftButtonUp="azalt"
Name="minusIcon"
Height="30"/>
<TextBlock Text="0"
Grid.Column="1"
Name="amountText"
VerticalAlignment="Center"
HorizontalAlignment="Center"
FontSize="20"/>
<Image Source="/Images/PopUp/icon_plus_red.png"
MouseLeftButtonUp="arttir"
Name="plusIcon"
Grid.Column="2"
Height="30"/>
</Grid>
If i understand your question correctly, You can achieve this behind code with C#. You should add the code below to your source code.
//Get ListViewItem
ListViewItem item = (ListViewItem)OrderList.Items.GetItemAt(SatirIndex);
//Get Content from item (use if you want read items value)
string deger = item.content;
//Set items content (use if you want set items value)
item.content = amountText.Text;
I'm trying set backcolor for all grid layout in my project using resource dictionary. This is code of file where i modify my grid.
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:Theme">
<SolidColorBrush x:Key="GridBackColor" Color="Red"/>
<Style TargetType="Grid">
<Setter Property="Background" Value="{StaticResource GridBackColor}"/>
<Setter Property="Opacity" Value="0.5"/>
</Style>
</ResourceDictionary>
After set Background property all controls on grid were disappear, but when i set opacity i can only say that all controls are under grid layout and any mouse events not work.
Here how it's look like:
this is my window code.
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="10*"/>
<ColumnDefinition Width="125"/>
<ColumnDefinition Width="20"/>
<ColumnDefinition Width="125"/>
<ColumnDefinition Width="10*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="10*"/>
<RowDefinition Height="40"/>
<RowDefinition Height="40"/>
<RowDefinition Height="20"/>
<RowDefinition Height="30"/>
<RowDefinition Height="10*"/>
</Grid.RowDefinitions>
<Label Content="Name" Grid.Column="1" Grid.Row="1" Grid.ColumnSpan="3" FontSize="20"
HorizontalAlignment="Stretch" VerticalAlignment="Center"/>
<TextBox Name="TbName" Grid.Column="1" Grid.Row="2" Grid.ColumnSpan="3" FontSize="20"
HorizontalAlignment="Stretch" />
<Button Content="Add" Name="BtAdd" Grid.Column="1" Grid.Row="4" IsDefault="True"
HorizontalAlignment="Right" VerticalAlignment="Center" Width="100" Click="BtAdd_Click"/>
<Button Content="Close" Name="BtClose" Grid.Column="3" Grid.Row="4" IsCancel="True"
HorizontalAlignment="Left" Width="100" Click="BtClose_Click"/>
</Grid>
When you applied you style globally to all the Grids in your application, the ones used inside other controls will also be affected. For instance take a look at the Window control (from the vs designer, left click on the window > Edit Template > Edit a copy)
<Window.Resources>
<ControlTemplate x:Key="WindowTemplateKey" TargetType="{x:Type Window}">
<Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}">
<Grid>
<AdornerDecorator>
<ContentPresenter/>
</AdornerDecorator>
<ResizeGrip x:Name="WindowResizeGrip" HorizontalAlignment="Right" IsTabStop="false" Visibility="Collapsed" VerticalAlignment="Bottom"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="ResizeMode" Value="CanResizeWithGrip"/>
<Condition Property="WindowState" Value="Normal"/>
</MultiTrigger.Conditions>
<Setter Property="Visibility" TargetName="WindowResizeGrip" Value="Visible"/>
</MultiTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
<Style x:Key="WindowStyle1" TargetType="{x:Type Window}">
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.WindowTextBrushKey}}"/>
<Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.WindowBrushKey}}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Window}">
<Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}">
<AdornerDecorator>
<ContentPresenter/>
</AdornerDecorator>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="ResizeMode" Value="CanResizeWithGrip">
<Setter Property="Template" Value="{StaticResource WindowTemplateKey}"/>
</Trigger>
</Style.Triggers>
</Style>
</Window.Resources>
Notice the Grid defined in the Border inside the ControlTemplate.
An easy fix to your issue is to assign a key to your style and assign it to the Grid manually:
<Style TargetType="Grid" x:Key="GridStyle">
<Setter Property="Background" Value="{StaticResource GridBackColor}"/>
<Setter Property="Opacity" Value="0.5"/>
</Style>
To use it:
<Grid Style="{StaticResource GridStyle}">
...
</Grid>
I have a next style:
<Style x:Key="Style_MainButtons" TargetType="ToggleButton">
<Setter Property="Width" Value="110" />
<Setter Property="Height" Value="110" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition />
</Grid.RowDefinitions>
<TextBlock x:Name="Text" HorizontalAlignment="Center" />
<Image x:Name="Image" Grid.Row="1" />
</Grid>
<ControlTemplate.Triggers>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Because there are few toggle buttons using this style and each have different text and image, so how can I call “TextBlock” and “Image” from style in the next code?
<ToggleButton x:Name="btnHorizontal"
Style="{StaticResource Style_MainButtons}"
Grid.Column="0"
Grid.Row="1"
Checked ="SetVersion"
Unchecked ="SetVersion"
IsChecked="True" >
</ToggleButton>
You can do something like this:
Style
<Style TargetType="ToggleButton">
<Setter Property="Width" Value="110" />
<Setter Property="Height" Value="110" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition />
</Grid.RowDefinitions>
<TextBlock x:Name="Text" HorizontalAlignment="Center" Text="{TemplateBinding Content}"/>
<Image x:Name="Image" Grid.Row="1" Source="{TemplateBinding Tag}" />
</Grid>
<ControlTemplate.Triggers>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Usage
<ToggleButton Content="Text" Tag="{Binding Path=Source, Source={StaticResource Image}}"></ToggleButton>
<ToggleButton Content="Another Text" Tag="{Binding Path=Source, Source={StaticResource Image}}"></ToggleButton>
Note: Replace my Tag-Binding with an valid Binding to your actual ImageSource
I want to make custom style for doubleupdown button like on example.
Example:
What i have
main problem is that <RepeatButton x:Name="PART_IncreaseButton" Grid.Row="0" IsTabStop="{TemplateBinding IsTabStop}" Style="{StaticResource CustomRepeatButtonStyle}"/> does not respond when i am clickin on it why?
Xaml code of me freak:
<Window.Resources>
<Style x:Key="CustomRepeatButtonStyle" TargetType="{x:Type RepeatButton}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type RepeatButton}">
<Grid x:Name="customgrid" Background="White">
<Polygon x:Name="custompolygon" Points="1,11 6,1 11,11" Fill="SkyBlue" VerticalAlignment="Center" HorizontalAlignment="Center">
</Polygon>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="true">
<Setter TargetName="custompolygon" Property="Fill" Value="black"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="CustomDoubleUpDownStyle" TargetType="{x:Type xctk:DoubleUpDown}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type xctk:DoubleUpDown}">
<Border BorderThickness="1" BorderBrush="Purple">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="0.3*"/>
<ColumnDefinition />
</Grid.ColumnDefinitions>
<Grid Grid.Column="0">
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<RepeatButton x:Name="PART_IncreaseButton" Grid.Row="0" IsTabStop="{TemplateBinding IsTabStop}" Style="{StaticResource CustomRepeatButtonStyle}"/>
<RepeatButton x:Name="PART_DecreaseButton" Grid.Row="1" IsTabStop="{TemplateBinding IsTabStop}"/>
</Grid>
<ContentPresenter Grid.Column="1" Content="{TemplateBinding Property=Value}" HorizontalAlignment="Center" VerticalAlignment="Center"/>
</Grid>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Grid>
<xctk:DoubleUpDown Width="180" Height="70" Style="{StaticResource CustomDoubleUpDownStyle}" Value="20"/>
</Grid>
In your XAML there are no functions bound to the click event (or any other event). In other words: From the programs point of view there is nothing to do, when any of your buttons get clicked. Is this your problem?
In this case add event handlers and modify the counter in your model accordingly.
When developing a custom control in WPF I noticed a strange clipping behavior. When I resize the control under a certain minimum boundaries/tress-hold it decides to clip the top 24 pixels of the control for reasons I don't understand.
It would be much appreciated if somebody could explain how i can achieve the desired graphical effect without clipping behavior as illustrated.
The behavior occurs with the following XAML. Note that the XAML is a stripped down to make the it compliant with standard .net 4.0 controls.
<Style x:Key="{ComponentResourceKey ResourceId=DataGridSelectAllButtonStyle, TypeInTargetAssembly={x:Type DataGrid}}" TargetType="{x:Type Button}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Grid>
<Rectangle x:Name="Border" Fill="{DynamicResource {x:Static SystemColors.ControlBrushKey}}" SnapsToDevicePixels="True"/>
<Polygon x:Name="Arrow" Fill="Black" HorizontalAlignment="Right" Margin="8,8,3,3" Opacity="0.15" Points="0,10 10,10 10,0" Stretch="Uniform" VerticalAlignment="Bottom"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Stroke" TargetName="Border" Value="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Fill" TargetName="Border" Value="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Visibility" TargetName="Arrow" Value="Collapsed"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="DataGridStyle1" TargetType="{x:Type DataGrid}">
<Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
<Setter Property="BorderBrush" Value="#FF688CAF"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="RowDetailsVisibilityMode" Value="VisibleWhenSelected"/>
<Setter Property="ScrollViewer.CanContentScroll" Value="true"/>
<Setter Property="ScrollViewer.PanningMode" Value="Both"/>
<Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type DataGrid}">
<Border Background="Transparent" Margin="0,24,0,0" >
<Border BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Background="{TemplateBinding Background}" Padding="{TemplateBinding Padding}"
SnapsToDevicePixels="True">
<ScrollViewer x:Name="DG_ScrollViewer" Focusable="false">
<ScrollViewer.Template>
<ControlTemplate TargetType="{x:Type ScrollViewer}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Button Grid.Row="0" Command="{x:Static DataGrid.SelectAllCommand}" Focusable="false" Style="{DynamicResource {ComponentResourceKey ResourceId=DataGridSelectAllButtonStyle, TypeInTargetAssembly={x:Type DataGrid}}}" Visibility="{Binding HeadersVisibility, ConverterParameter={x:Static DataGridHeadersVisibility.All}, Converter={x:Static DataGrid.HeadersVisibilityConverter}, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}" Width="{Binding CellsPanelHorizontalOffset, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"/>
<DataGridColumnHeadersPresenter Grid.Row="0" x:Name="PART_ColumnHeadersPresenter" Grid.Column="1" Visibility="{Binding HeadersVisibility, ConverterParameter={x:Static DataGridHeadersVisibility.Column}, Converter={x:Static DataGrid.HeadersVisibilityConverter}, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"/>
<Grid VerticalAlignment="Top" Grid.Row="0" Grid.Column="1" Grid.ColumnSpan="1" ClipToBounds="False">
<Grid.RenderTransform>
<TranslateTransform Y="-24" />
</Grid.RenderTransform>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="{Binding NonFrozenColumnsViewportHorizontalOffset, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Rectangle Fill="Yellow" Grid.Row="1" Grid.ColumnSpan="3" Grid.Column="1" Height="48" />
</Grid>
</Grid>
</ControlTemplate>
</ScrollViewer.Template>
<ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</ScrollViewer>
</Border>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsGrouping" Value="true">
<Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
</Trigger>
</Style.Triggers>
</Style>
<DataGrid AutoGenerateColumns="False" HorizontalAlignment="Left" Margin="12,12,0,12" Name="dataGrid1" Width="868" FrozenColumnCount="2"
ScrollViewer.HorizontalScrollBarVisibility="Visible" CanUserSortColumns="False" CanUserReorderColumns="False"
AreRowDetailsFrozen="True" CanUserAddRows="False" Style="{StaticResource DataGridStyle1}"
ScrollViewer.VerticalScrollBarVisibility="Visible">
<DataGrid.Columns>
<DataGridTextColumn Header="Layer Name" Width="250" IsReadOnly="True" />
<DataGridHyperlinkColumn Header="" Width="150" IsReadOnly="True" />
<DataGridTemplateColumn Width="*" HeaderStyle="{StaticResource DataGridColumnHeaderStyle}" IsReadOnly="True">
<DataGridTemplateColumn.Header>
<Grid Height="18">
<TextBlock Text="100.0f" Margin="0,-10" />
</Grid>
</DataGridTemplateColumn.Header>
</DataGridTemplateColumn>
</DataGrid.Columns>
<DataGrid.GroupStyle>
<GroupStyle>
<GroupStyle.ContainerStyle>
<Style TargetType="{x:Type GroupItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type GroupItem}">
<StackPanel>
<TextBlock Text="test" />
<ItemsPresenter />
</StackPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</GroupStyle.ContainerStyle>
</GroupStyle>
</DataGrid.GroupStyle>
</DataGrid>
So after a few days of fiddling I found the culprit to be GetLayoutClip method. This method returns clipping geometry only if the bounds of the control is smaller than the minimum bounds.
Easiest solution to override this behavior was to make a custom control inherit from the said base control. And to construct new clipping geometry with the extra margin taken into account.