public static void WriteExcel(System.Data.DataTable dt,string fileName)

        {

            NPOI.XSSF.UserModel.XSSFWorkbook book = new NPOI.XSSF.UserModel.XSSFWorkbook();

            NPOI.SS.UserModel.ISheet sheet = book.CreateSheet(dt.TableName);

            NPOI.SS.UserModel.IRow row = sheet.CreateRow();

            row.HeightInPoints = ;

            NPOI.SS.UserModel.ICellStyle headStyle = book.CreateCellStyle();

            headStyle.BorderBottom = NPOI.SS.UserModel.BorderStyle.Thin;

            headStyle.BorderLeft = NPOI.SS.UserModel.BorderStyle.Thin;

            headStyle.BorderRight = NPOI.SS.UserModel.BorderStyle.Thin;

            headStyle.BorderTop = NPOI.SS.UserModel.BorderStyle.Thin;

            headStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;

            headStyle.VerticalAlignment = NPOI.SS.UserModel.VerticalAlignment.Justify;

            headStyle.FillForegroundColor = NPOI.HSSF.Util.HSSFColor.PaleBlue.Index;

            headStyle.FillPattern = NPOI.SS.UserModel.FillPattern.SolidForeground;

            NPOI.SS.UserModel.IFont font = book.CreateFont();

            font.Boldweight = (short)NPOI.SS.UserModel.FontBoldWeight.Bold;

            headStyle.SetFont(font);

            NPOI.SS.UserModel.ICellStyle style = book.CreateCellStyle();

            style.BorderBottom = NPOI.SS.UserModel.BorderStyle.Thin;

            style.BorderLeft = NPOI.SS.UserModel.BorderStyle.Thin;

            style.BorderRight = NPOI.SS.UserModel.BorderStyle.Thin;

            style.BorderTop = NPOI.SS.UserModel.BorderStyle.Thin;

            style.VerticalAlignment = NPOI.SS.UserModel.VerticalAlignment.Justify;

            for (int i = ; i < dt.Columns.Count; i++)

            {

                NPOI.SS.UserModel.ICell cell = row.CreateCell(i);

                cell.CellStyle = headStyle;

                cell.SetCellValue(dt.Columns[i].ColumnName);

            }

            for (int i = ; i < dt.Rows.Count; i++)

            {

                NPOI.SS.UserModel.IRow row2 = sheet.CreateRow(i + );

                row2.HeightInPoints = ;

                for (int j = ; j < dt.Columns.Count; j++)

                {

                    NPOI.SS.UserModel.ICell cell = row2.CreateCell(j);

                    cell.CellStyle = style;

                    cell.SetCellValue(Convert.ToString(dt.Rows[i][j]));

                }

            }

            //自适应列宽度

            for (int i = ; i <= dt.Columns.Count; i++)

            {

                sheet.AutoSizeColumn(i);

            }

            FileStream fs = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);

            book.Write(fs);

            fs.Dispose();

            book = null;

        }