npoi读取excel 使用Npoi操作excel的解决办法

//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