private void addNewExtensionSetting_Click(object sender, RoutedEventArgs e)
        {
            AddNewHandlerWindow addhandler = new AddNewHandlerWindow();

            if (addhandler.ShowDialog() == true)
            {
                ReloadCustomAssociations();
            }
        }
        private void editExtensionSetting_Click(object sender, RoutedEventArgs e)
        {
            Int32 selected_index = pathGrid.SelectedIndex;

            if (selected_index == -1)
            {
                return;
            }
            AddNewHandlerWindow anhw = new AddNewHandlerWindow(pathGrid.Items[selected_index] as FileAssociation, selected_index);

            if (anhw.ShowDialog() == true)
            {
                ReloadCustomAssociations();
            }
        }