public class GridViewColumnTest : GridViewColumn
    {
        public static readonly DependencyProperty TestProperty = DependencyProperty.Register
         (
         "Test",
         typeof(string),
         typeof(GridViewColumnTest),
         new PropertyMetadata(string.Empty)
        );

        public string Test
        {
            get { return (string)GetValue(TestProperty); }
            set { SetValue(TestProperty, value); }
        }

        public GridViewColumnTest()
        {

        }

    }