private void BtnExport2TxtClick(object sender, RoutedEventArgs e)
{
var mc = dg_Categories.SelectedItem as CategoryModel;
var cl = new List <CategoryModel>();
cl.Add(mc);
var sc = new SourceGenerator(cl);
var slist = sc.PrintPeripheryForCategory(mc.Name);
var outWindow = new TextBufferView(slist);
outWindow.Show();
}