private void AddLabel(int length, string content, Brush back)
{
grd_main.ColumnDefinitions.Add(new ColumnDefinition()
{
Width = new GridLength(Math.Abs(length), GridUnitType.Star)
});
Label lb = new Label();
lb.Content = content;
lb.Background = back;
lb.Foreground = Brushes.Black;
lb.FontSize = 12;
lb.HorizontalContentAlignment = HorizontalAlignment.Center;
lb.VerticalContentAlignment = VerticalAlignment.Center;
int index = grd_main.Children.Add(lb);
lb.SetValue(Grid.ColumnProperty, index);
}