private static void OnIsOrientedPropertyChanged(DependencyObject d,
                                                        DependencyPropertyChangedEventArgs e)
        {
            RadialPanel source = (RadialPanel)d;
            bool        value  = (bool)e.NewValue;

            if (source.ignorePropertyChange)
            {
                source.ignorePropertyChange = false;
                return;
            }
            source.InvalidateMeasure();
        }
        private static void OnItemHeightOrWidthPropertyChanged(DependencyObject d,
                                                               DependencyPropertyChangedEventArgs e)
        {
            RadialPanel source = (RadialPanel)d;
            double      value  = (double)e.NewValue;

            if (source.ignorePropertyChange)
            {
                source.ignorePropertyChange = false;
                return;
            }
            if (!double.IsNaN(value) && ((value <= 0.0) || double.IsPositiveInfinity(value)))
            {
                source.ignorePropertyChange = true;
                source.SetValue(e.Property, (double)e.OldValue);
                throw new ArgumentException("OnItemHeightOrWidthPropertyChanged InvalidValue", "value");
            }
            source.InvalidateMeasure();
        }