How to Stretch WPF Tab Item Headers to Parent Control Width

Question

Is there a way in XAML to cause the tab item headers to stretch across the width of the tab control?

For example, I have three tabs: red, blue and green. If I have a

Answer 1

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: