简单代码打印出不断长大的文字[C#]

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Printing;

namespace PrintTest3
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            PrintDocument pd = new PrintDocument();

            //设置边距
            //Margins margin = new Margins(20, 20, 20, 20);
            //pd.DefaultPageSettings.Margins=margin;

            pd.PrintPage += pd_PrintPage;
            pd.Print();
        }

        private void pd_PrintPage(object sender, PrintPageEventArgs e)
        {
            for (int i = 0; i < 10; i++)
            {
                //动态获取字符的高度
                SizeF string_size = e.Graphics.MeasureString("第{0}行", new Font("宋体", 12+i));
                e.Graphics.DrawString
                    (
                    string.Format("第{0}行", i), new Font("宋体", 12 + i), 
                    Brushes.Black, 100, 100 + string_size.Height*i
                    );
            }
        }
    }
}