//创建xls文件         private void button1_Click(object sender, EventArgs e)         {             //创建工作薄             HSSFWorkbook wk = new HSSFWorkbook();             //创建一个名称为mySheet的表             ISheet tb = wk.CreateSheet("mySheet");             //创建一行，此行为第二行             IRow row = tb.CreateRow(1);             for (int i = 0; i < 20; i++)                {                 ICell cell = row.CreateCell(i);  //在第二行中创建单元格                 cell.SetCellValue(i);//循环往第二行的单元格中添加数据             }             using (FileStream fs = File.OpenWrite(@"c:/myxls.xls")) //打开一个xls文件，如果没有则自行创建，如果存在myxls.xls文件则在创建是不要打开该文件！             {                 wk.Write(fs);   //向打开的这个xls文件中写入mySheet表并保存。                 MessageBox.Show("提示：创建成功！");             }         }

//读取xls文件         private void button2_Click(object sender, EventArgs e)         {   StringBuilder sbr = new StringBuilder();             using (FileStream fs = File.OpenRead(@"c:/myxls.xls"))   //打开myxls.xls文件             {                 HSSFWorkbook wk = new HSSFWorkbook(fs);   //把xls文件中的数据写入wk中                 for (int i = 0; i < wk.NumberOfSheets; i++)  //NumberOfSheets是myxls.xls中总共的表数                 {                     ISheet sheet = wk.GetSheetAt(i);   //读取当前表数据                     for (int j = 0; j <= sheet.LastRowNum; j++)  //LastRowNum 是当前表的总行数                     {                         IRow row = sheet.GetRow(j);  //读取当前行数据                         if (row != null)                         {                             sbr.Append("-------------------------------------\r\n"); //读取行与行之间的提示界限                             for (int k = 0; k <= row.LastCellNum; k++)  //LastCellNum 是当前行的总列数                             {                                 ICell cell = row.GetCell(k);  //当前表格                                 if (cell != null)                                 {                                                                       sbr.Append(cell.ToString());   //获取表格中的数据并转换为字符串类型                                 }                             }                         }                     }                 }                           }             sbr.ToString();             using (StreamWriter wr = new StreamWriter(new FileStream(@"c:/myText.txt", FileMode.Append)))  //把读取xls文件的数据写入myText.txt文件中             {                 wr.Write(sbr.ToString());                 wr.Flush();             }         }

//创建一个常用的xls文件         private void button3_Click(object sender, EventArgs e)         {                      IWorkbook wb = new HSSFWorkbook();             //创建表              ISheet sh = wb.CreateSheet("zhiyuan");             //设置单元的宽度              sh.SetColumnWidth(0, 15 * 256);             sh.SetColumnWidth(1, 35 * 256);             sh.SetColumnWidth(2, 15 * 256);             sh.SetColumnWidth(3, 10 * 256);             int i = 0;             #region 练习合并单元格             sh.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 0, 0, 3));             //CellRangeAddress（）该方法的参数次序是：开始行号，结束行号，开始列号，结束列号。             IRow row0 = sh.CreateRow(0);             row0.Height = 20 * 20;             ICell icell1top0 = row0.CreateCell(0);             icell1top0.CellStyle = Getcellstyle(wb, stylexls.头);             icell1top0.SetCellValue("标题合并单元");             #endregion             i++;             #region 设置表头             IRow row1 = sh.CreateRow(1);             row1.Height = 20 * 20;             ICell icell1top = row1.CreateCell(0);             icell1top.CellStyle = Getcellstyle(wb, stylexls.头);             icell1top.SetCellValue("网站名");             ICell icell2top = row1.CreateCell(1);             icell2top.CellStyle = Getcellstyle(wb, stylexls.头);             icell2top.SetCellValue("网址");             ICell icell3top = row1.CreateCell(2);             icell3top.CellStyle = Getcellstyle(wb, stylexls.头);             icell3top.SetCellValue("百度快照");             ICell icell4top = row1.CreateCell(3);             icell4top.CellStyle = Getcellstyle(wb, stylexls.头);             icell4top.SetCellValue("百度收录");             #endregion              using(FileStream stm=File.OpenWrite(@"c:/myMergeCell.xls"))             {                 wb.Write(stm);                 MessageBox.Show("提示：创建成功！");             }         }           #region 定义单元格常用到样式的枚举         public enum stylexls         {             头,             url,             时间,             数字,             钱,             百分比,             中文大写,             科学计数法,             默认         }         #endregion         #region 定义单元格常用到样式         static ICellStyle Getcellstyle(IWorkbook wb, stylexls str)         {             ICellStyle cellStyle = wb.CreateCellStyle();             //定义几种字体              //也可以一种字体，写一些公共属性，然后在下面需要时加特殊的              IFont font12 = wb.CreateFont();             font12.FontHeightInPoints = 10;             font12.FontName = "微软雅黑";             IFont font = wb.CreateFont();             font.FontName = "微软雅黑";             //font.Underline = 1;下划线              IFont fontcolorblue = wb.CreateFont();             fontcolorblue.Color = HSSFColor.OLIVE_GREEN.BLUE.index;             fontcolorblue.IsItalic = true;//下划线              fontcolorblue.FontName = "微软雅黑";             //边框              cellStyle.BorderBottom = NPOI.SS.UserModel.BorderStyle.DOTTED;             cellStyle.BorderLeft = NPOI.SS.UserModel.BorderStyle.HAIR;             cellStyle.BorderRight = NPOI.SS.UserModel.BorderStyle.HAIR;             cellStyle.BorderTop = NPOI.SS.UserModel.BorderStyle.DOTTED;             //边框颜色              cellStyle.BottomBorderColor = HSSFColor.OLIVE_GREEN.BLUE.index;             cellStyle.TopBorderColor = HSSFColor.OLIVE_GREEN.BLUE.index;             //背景图形，我没有用到过。感觉很丑              //cellStyle.FillBackgroundColor = HSSFColor.OLIVE_GREEN.BLUE.index;              //cellStyle.FillForegroundColor = HSSFColor.OLIVE_GREEN.BLUE.index;              cellStyle.FillForegroundColor = HSSFColor.WHITE.index;             // cellStyle.FillPattern = FillPatternType.NO_FILL;              cellStyle.FillBackgroundColor = HSSFColor.BLUE.index;             //水平对齐              cellStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.LEFT;             //垂直对齐              cellStyle.VerticalAlignment = VerticalAlignment.CENTER;             //自动换行              cellStyle.WrapText = true;             //缩进;当设置为1时，前面留的空白太大了。希旺官网改进。或者是我设置的不对              cellStyle.Indention = 0;             //上面基本都是设共公的设置              //下面列出了常用的字段类型              switch (str)             {                 case stylexls.头:                     // cellStyle.FillPattern = FillPatternType.LEAST_DOTS;                      cellStyle.SetFont(font12);                     break;                 case stylexls.时间:                     IDataFormat datastyle = wb.CreateDataFormat();                     cellStyle.DataFormat = datastyle.GetFormat("yyyy/mm/dd");                     cellStyle.SetFont(font);                     break;                 case stylexls.数字:                     cellStyle.DataFormat = HSSFDataFormat.GetBuiltinFormat("0.00");                     cellStyle.SetFont(font);                     break;                 case stylexls.钱:                     IDataFormat format = wb.CreateDataFormat();                     cellStyle.DataFormat = format.GetFormat("￥#,##0");                     cellStyle.SetFont(font);                     break;                 case stylexls.url:                     fontcolorblue.Underline = 1;                     cellStyle.SetFont(fontcolorblue);                     break;                 case stylexls.百分比:                     cellStyle.DataFormat = HSSFDataFormat.GetBuiltinFormat("0.00%");                     cellStyle.SetFont(font);                     break;                 case stylexls.中文大写:                     IDataFormat format1 = wb.CreateDataFormat();                     cellStyle.DataFormat = format1.GetFormat("[DbNum2][$-804]0");                     cellStyle.SetFont(font);                     break;                 case stylexls.科学计数法:                     cellStyle.DataFormat = HSSFDataFormat.GetBuiltinFormat("0.00E+00");                     cellStyle.SetFont(font);                     break;                 case stylexls.默认:                     cellStyle.SetFont(font);                     break;             }             return cellStyle;         }         #endregion