开源项目 06 NPOI

using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2.test1
{
    public class Class6
    {
        public void test1()
        {
            //DataSet ds = ExcelToDataSet(true, "1.xlsx");
            //DataSet ds2 = ExcelToDataSet(false, "1.xlsx");

            //Console.WriteLine(ds.Tables.Count);
            //Console.WriteLine(ds.Tables[0].Rows.Count);

            Console.WriteLine(GetExcelColumnName());
        }

        /// <summary>
        /// Excel转换为DataSet
        /// </summary>
        /// <param name="isFirstRowColumn"></param>
        /// <param name="fileName"></param>
        /// <returns></returns>
        public DataSet ExcelToDataSet(bool isFirstRowColumn, string fileName)
        {
            bool IsSupportFormula = true;//是否支持Excel公式
            IWorkbook workbook = null;
            DataSet ds = new DataSet();
            var fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);

            #region 初始化Excel

            if (fileName.IndexOf(".xlsx") > )
            {
                workbook = new XSSFWorkbook(fs);
            }
            else if (fileName.IndexOf(".xls") > )
            {
                workbook = new HSSFWorkbook(fs);
            }
            else
            {
                throw new Exception("格式错误！");
            }
            #endregion

            for (int sheetIndex = ; sheetIndex < workbook.NumberOfSheets; sheetIndex++)
            {
                DataTable myTable = new DataTable();
                ISheet sheet = null;
                int sheetNum = sheetIndex;
                sheet = workbook.GetSheetAt(sheetNum);

                #region 工作表不能为空

                if (sheet == null)
                {
                    string str = "";
                    for (int i = ; i < workbook.NumberOfSheets; i++)
                    {
                        str += workbook.GetSheetAt(i).SheetName + ",";
                    }
                    str = workbook.NumberOfSheets + str;
                    throw new Exception($"sheet不能为空！参数：{sheetNum} 工作簿信息：{str}");
                }
                #endregion

                #region Excel最大列数

                int MaxColumnNum = ;
                for (int i = ; i < sheet.LastRowNum; i++)
                {
                    var row = sheet.GetRow(i);
                    if (row == null)
                    {
                        continue;
                    }
                    if (row.LastCellNum > MaxColumnNum)
                    {
                        MaxColumnNum = row.LastCellNum;
                    }
                }
                #endregion

                //Excel行数
                int MaxRowNum = sheet.LastRowNum;

                #region table新增列

                for (int i = ; i < MaxColumnNum; ++i)
                {
                    //首行为列
                    if (isFirstRowColumn)
                    {
                        bool addEmptyCell = true;//是否添加空列
                        ICell cell = sheet.GetRow().GetCell(i);
                        if (cell != null)
                        {
                            //table列赋值
                            string cellValue = "";//列名
                            if (cell.CellType == CellType.Numeric)
                            {
                                cellValue = cell.NumericCellValue.ToString();
                            }
                            else
                            {
                                cellValue = cell.StringCellValue;
                            }
                            if (!string.IsNullOrWhiteSpace(cellValue))
                            {
                                //列数据为Excel的数据
                                addEmptyCell = false;

                                if (myTable.Columns.Contains(cellValue))
                                {
                                    throw new Exception($"已包含列：{cellValue}，工作表：{sheet.SheetName}");
                                }
                                myTable.Columns.Add(new DataColumn(cellValue));
                            }
                        }
                        if (addEmptyCell)
                        {
                            myTable.Columns.Add(new DataColumn(""));//列数据为空
                        }
                    }
                    else
                    {
                        myTable.Columns.Add(new DataColumn(i + ""));
                    }
                }
                #endregion

                //起始行
                int startRow = ;
                if (isFirstRowColumn)
                {
                    startRow = ;
                }

                #region DataTable赋值

                for (int i = startRow; i <= MaxRowNum; ++i)
                {
                    IRow row = sheet.GetRow(i);
                    if (row == null) continue;

                    DataRow NewRow = myTable.NewRow();
                    for (int j = row.FirstCellNum; j < row.LastCellNum; ++j)
                    {
                        ICell cell = row.GetCell(j);
                        string value = "";
                        if (cell != null)
                        {
                            //table行赋值
                            if (cell.CellType == CellType.Numeric)
                            {
                                value = cell.NumericCellValue.ToString();
                                //if ((j == 0) && ((i == 6) || (i == 12)))
                                //{
                                //    //特殊的几个单元格 转换为 日期格式
                                //    value = ToDateTimeValue(cell.NumericCellValue.ToString());
                                //}

                            }
                            else if (cell.CellType == CellType.Formula)
                            {
                                if (IsSupportFormula)
                                {
                                    try
                                    {
                                        #region 公式计算

                                        if (fileName.IndexOf(".xlsx") > )
                                        {
                                            XSSFFormulaEvaluator e = new XSSFFormulaEvaluator(cell.Sheet.Workbook);
                                            e.EvaluateInCell(cell);
                                            value = cell.ToString();
                                        }
                                        else if (fileName.IndexOf(".xls") > )
                                        {
                                            HSSFFormulaEvaluator e = new HSSFFormulaEvaluator(cell.Sheet.Workbook);
                                            e.EvaluateInCell(cell);
                                            value = cell.ToString();
                                        }
                                        #endregion
                                    }
                                    catch
                                    {
                                        //日期
                                        if (DateUtil.IsCellDateFormatted(cell))
                                        {
                                            value = cell.DateCellValue.ToString("yyyy-MM-dd");
                                        }
                                        else
                                        {
                                            value = cell.NumericCellValue.ToString();
                                        }
                                    }
                                }
                                else
                                {
                                    throw new Exception($"Excel含有公式  fileName:{fileName} sheetIndex:{sheetIndex + 1}  rowIndex:{i + 1}  colIndex:{j + 1}\r\n");
                                }

                            }
                            else
                            {
                                //row.GetCell(j).SetCellType(CellType.String);
                                value = cell.StringCellValue;
                            }
                        }
                        NewRow[j] = value;
                    }
                    myTable.Rows.Add(NewRow);
                }
                #endregion

                ds.Tables.Add(myTable);
            }
            return ds;
        }

        /// <summary>
        /// 数字格式的时间 转换为 字符串格式的时间
        /// 数字格式的时间 如： 42095.7069444444/0.650694444444444
        /// </summary>
        /// <param name="timeStr">数字,如:42095.7069444444/0.650694444444444</param>
        /// <returns>日期/时间格式</returns>
        public string ToDateTimeValue(string strNumber)
        {
            if (!string.IsNullOrWhiteSpace(strNumber))
            {
                Decimal tempValue;
                //先检查 是不是数字;
                if (Decimal.TryParse(strNumber, out tempValue))
                {
                    //天数,取整
                    int day = Convert.ToInt32(Math.Truncate(tempValue));
                    //这里也不知道为什么. 如果是小于32,则减1,否则减2
                    //日期从1900-01-01开始累加
                    // day = day < 32 ? day - 1 : day - 2;
                    DateTime dt = new DateTime(, , ).AddDays(day <  ? (day - ) : (day - ));

                    //小时:减掉天数,这个数字转换小时:(* 24)
                    Decimal hourTemp = (tempValue - day) * ;//获取小时数
                                                              //取整.小时数
                    int hour = Convert.ToInt32(Math.Truncate(hourTemp));
                    //分钟:减掉小时,( * 60)
                    //这里舍入,否则取值会有1分钟误差.
                    Decimal minuteTemp = Math.Round((hourTemp - hour) * , );//获取分钟数
                    int minute = Convert.ToInt32(Math.Truncate(minuteTemp));
                    //秒:减掉分钟,( * 60)
                    //这里舍入,否则取值会有1秒误差.
                    Decimal secondTemp = Math.Round((minuteTemp - minute) * , );//获取秒数
                    int second = Convert.ToInt32(Math.Truncate(secondTemp));

                    //时间格式:00:00:00
                    string resultTimes = string.Format("{0}:{1}:{2}",
                            (hour <  ? ("" + hour) : hour.ToString()),
                            (minute <  ? ("" + minute) : minute.ToString()),
                            (second <  ? ("" + second) : second.ToString()));

                    if (day > )
                        return string.Format("{0} {1}", dt.ToString("yyyy-MM-dd"), resultTimes);
                    else
                        return resultTimes;
                }
            }
            return string.Empty;
        }

        /// <summary>
        /// 获取Excel的列名
        /// 这个还是有很多bug 先将就用吧
        /// </summary>
        /// <param name="index"></param>
        /// <returns></returns>
        public string GetExcelColumnName(int index)
        {
            var arr = new List<string>() { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z" };
            string name = "";

            if (index <= arr.Count)
            {
                for (int i = ; i < arr.Count; i++)
                {
                    if ((i + ) == index)
                    {
                        name = arr[i];
                    }
                }
            }
            else
            {
                int num = ;

                num = index / arr.Count;
                for (int i = ; i < num; i++)
                {
                    name += "A";
                }

                num = index % arr.Count;
                name += arr[num - ];
            }

            if ((name.Length >= ))
            {
                //&& (name.Length - 2 <= arr.Count - 1)
                name = arr[name.Length - ] + name.Substring(name.Length - , );
            }
            return name;
        }

        /// <summary>
        /// DataTable 转换为 Html，点击单元格 输出 单元格所在的 行和列
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        public string GetHtmlString(DataTable dt)
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("<html><head>");
            sb.Append("<title>Excel转换为Table</title>");
            sb.Append("<meta http-equiv='content-type' content='text/html; charset=GB2312'> ");
            sb.Append("<style type=text/css>");
            sb.Append("td{font-size: 9pt;border:solid 1 #000000;}");
            sb.Append("table{padding:3 0 3 0;border:solid 1 #000000;margin:0 0 0 0;BORDER-COLLAPSE: collapse;}");
            sb.Append("</style>");
            sb.Append("</head>");
            sb.Append("<body>");
            sb.Append("<table cellSpacing='0' cellPadding='0' width ='100%' border='1'>");
            sb.Append("<tr valign='middle'>");
            sb.Append("<td><b></b></td>");
            foreach (DataColumn column in dt.Columns)
            {
                sb.Append("<td><b><span>" + column.ColumnName + "</span></b></td>");
            }
            sb.Append("</tr>");
            int iColsCount = dt.Columns.Count;
            int rowsCount = dt.Rows.Count - ;
            for (int j = ; j <= rowsCount; j++)
            {
                sb.Append("<tr>");
                sb.Append("<td>" + ((int)(j + )).ToString() + "</td>");
                for (int k = ; k <= iColsCount - ; k++)
                {
                    sb.Append("<td>");
                    object obj = dt.Rows[j][k];
                    if (obj == DBNull.Value)
                    {
                        obj = "&nbsp;";//如果是NULL则在HTML里面使用一个空格替换之
                    }
                    if (obj.ToString() == "")
                    {
                        obj = "&nbsp;";
                    }
                    string strCellContent = obj.ToString().Trim();
                    sb.Append("<span>" + strCellContent + "</span>");
                    sb.Append("</td>");
                }
                sb.Append("</tr>");
            }
            sb.Append("</table>");

            //点击单元格 输出 行和列
            sb.Append("<script src='https://cdn.bootcss.com/jquery/1.12.4/jquery.min.js'></script>");
            sb.Append("<script type='text/javascript'>");
            sb.Append("$('table tbody').on('click', 'td', function (e) {");
            sb.Append("var row = $(this).parent().prevAll().length-1 ;");
            sb.Append("var column = $(this).prevAll().length-1 ;");
            sb.Append("var str = 'dt.Rows[' + row + '][' + column + '].ToString()';");
            sb.Append("console.log(str);alert(str);");
            sb.Append("});");
            sb.Append("</script>");

            sb.Append("</body></html>");
            return sb.ToString();
        }

    }
}