C#] 打印出不断长大的文字

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
                    );
            }
        }
    }
}