WPF tabitem positioning

Question

What is the proper way of positioning for example three tabitems at the very top left corner and one at the very top right corner of a tab control using WPF?

I have tried to move the fourth tabitem to the right by changing its margin but this doesn't produce a good result; first of all it is cut short and second of all it does not display correctly when selected.

Answer 1

The problem is that the TabPanel, which is used internally by the TabControl to lay out the tabs, does not seem to support what you want. A quick workaround would be to replace the TabPanel by something else, for example, a DockPanel:

<Window x:Class="Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="300" Width="300">
    <TabControl>
        <TabControl.Template>
            <ControlTemplate TargetType="TabControl">
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto"/>
                        <RowDefinition Height="*"/>
                    </Grid.RowDefinitions>
                    <Border BorderThickness="0,0,1,1" BorderBrush="#D0CEBF" Grid.Row="1">
                        <Border BorderThickness="{TemplateBinding BorderThickness}" 
                                BorderBrush="{TemplateBinding BorderBrush}">
                            <Border Background="{TemplateBinding Background}">
                                <ContentPresenter ContentSource="SelectedContent"/>
                            </Border>
                        </Border>
                    </Border>
                    <DockPanel IsItemsHost="True" LastChildFill="False" Margin="2,2,2,0" />
                </Grid>
            </ControlTemplate>
        </TabControl.Template>

        <TabItem Header="Item 1" />
        <TabItem Header="Item 2" />
        <TabItem Header="Item 3" />
        <TabItem Header="Item 4" DockPanel.Dock="Right" />
    </TabControl>
</Window>

(Reference: This is a modified version of an MSDN example for styling a TabControl.)

The simple DockPanel doesn't work as smooth as the TabPanel -- the tabs "jump" a bit when switching between them, but this might get you started. Maybe subclassing the TabPanel and overriding the relevant parts would give you a more accurate result; I guess it depends on how much effort you want to put into this.