在用NPOI导出EXCEL的时候设置分页，在网上有查到用sheet1.SetRowBreak(i)方法，但一直都没有起到作用。经过研究是要设置 sheet1.FitToPage = false; 而这个属性默认是true的，怪不得一直设置都不起作用。
设置打印标题用
hssfworkbook.SetRepeatingRowsAndColumns(0, 0, 5, 0, 5);
但最新版本已经有新的方法了。
sheet.RepeatingRows=new CellRangeAddress(0,5,0,5)
Sheet sheet1 = hssfworkbook.CreateSheet("Sheet1");
sheet1.SetMargin(MarginType.RightMargin, (double)0.5);
sheet1.SetMargin(MarginType.TopMargin, (double)0.6);
sheet1.SetMargin(MarginType.LeftMargin, (double)0.4);
sheet1.SetMargin(MarginType.BottomMargin, (double)0.3);
sheet1.PrintSetup.Copies = ;
sheet1.PrintSetup.NoColor = true;
sheet1.PrintSetup.Landscape = true;
sheet1.PrintSetup.PaperSize = (short)PaperSize.A4;
sheet1.PrintSetup.FitHeight = ;
sheet1.PrintSetup.FitWidth = ;
sheet1.IsPrintGridlines = true;
//是否自适应界面
sheet1.FitToPage = false;
//设置打印标题
hssfworkbook.SetRepeatingRowsAndColumns(, , , , );