Customized TabItem in ResourceDictionary
===

I have created a TabItem in a ResourceDictionary and use it in my UserControl but the defined content won't show up, why and how to fix this?

The ResourceDic:

    <ResourceDictionary
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk"
        xmlns:toolkit="http://schemas.microsoft.com/winfx/2006/xaml/presentation/toolkit">
        <ControlTemplate x:Key="T1" TargetType="sdk:TabItem">
            <sdk:TabItem>
                <sdk:TabItem.Header>
                    <StackPanel Orientation="Horizontal">
                        <sdk:Label Content="{TemplateBinding Header}"/>
                        <Button Content="X" Margin="15,0,0,0"/>
                    </StackPanel>
                </sdk:TabItem.Header>
    			
                <toolkit:DockPanel MinWidth="600">
                    <Grid toolkit:DockPanel.Dock="Left">
                        <sdk:Label Grid.Row="2" Grid.Column="0" Content="Pic:"/>
                        ...
                    </Grid>
                </toolkit:DockPanel>
    			
            </sdk:TabItem>
        </ControlTemplate>
    </ResourceDictionary>
    

The UserControl:

    <UserControl x:Class="PortView" ....>
        <UserControl.Resources>
                    <ResourceDictionary Source="PortfolioTemplateDictionary.xaml" />
        </UserControl.Resources>
        
        <Grid>
    		<sdk:TabItem Template="{StaticResource TextseiteTemplate}" Header="Page 2"/>
    	</Grid	
    	...
    </UserControl>