How to Stretch WPF Tab Item Headers to Parent Control Width

I took Jordan's example and made some changes to it. This version should work for any number of tabs:

namespace WpfApplication1.Converters{    public class TabSizeConverter : IMultiValueConverter    {        public object Convert(object[] values, Type targetType, object parameter,            System.Globalization.CultureInfo culture)        {            TabControl tabControl = values[0] as TabControl;            double width = tabControl.ActualWidth / tabControl.Items.Count;            //Subtract 1, otherwise we could overflow to two rows.            return (width <= 1) ? 0 : (width - 1);        }        public object[] ConvertBack(object value, Type[] targetTypes, object parameter,            System.Globalization.CultureInfo culture)        {            throw new NotSupportedException();        }    }}

Same namespace in the xaml:

xmlns:local="clr-namespace:WpfApplication1.Converters"

And this will make all tabs use it:

<Window.Resources>    <local:TabSizeConverter x:Key="tabSizeConverter" />    <Style TargetType="{x:Type TabItem}">        <Setter Property="Width">            <Setter.Value>                <MultiBinding Converter="{StaticResource tabSizeConverter}">                    <Binding RelativeSource="{RelativeSource Mode=FindAncestor,            AncestorType={x:Type TabControl}}" />                    <Binding RelativeSource="{RelativeSource Mode=FindAncestor,            AncestorType={x:Type TabControl}}" Path="ActualWidth" />                </MultiBinding>            </Setter.Value>        </Setter>    </Style></Window.Resources>

Everyone seems to be going the converter route, but it really is as simple as using a UniformGrid with Rows set to 1 in the TabControl template, in place of the TabPanel. Of course, you will have to re-template it, but this isn't too bad.

I was able to do this using a Converter like so:

namespace WpfApplication1.Converters{    public class SizeConverter : IValueConverter    {        #region IValueConverter Members        public object Convert(object value, Type targetType, object parameter,            System.Globalization.CultureInfo culture)        {            double width = Double.Parse(value.ToString());            //Subtract 1, otherwise we could overflow to two rows.            return .25 * width - 1;        }        public object ConvertBack(object value, Type targetType, object parameter,            System.Globalization.CultureInfo culture)        {            throw new NotSupportedException();        }        #endregion    }}

Then adding the namespace to my xaml:

xmlns:local="clr-namespace:WpfApplication1.Converters"

Then making all of the TabItems use the converter:

<Window.Resources>        <local:SizeConverter x:Key="sizeConverter" />        <Style TargetType="{x:Type TabItem}">            <Setter Property="Width" Value="{Binding ElementName=x_Grid, Path=ActualWidth, Converter={StaticResource sizeConverter}}" />        </Style>    </Window.Resources>

x_Grid is the x:Name of the parent element I want the tabs to be 1/4 of, if that makes sense.