C#--上文Excel文件数据获取

Excel文件上传，后台初次认定的只是个有大小的文件流，要想获取上传的数据，则需要用到NPOl

获取文件流

HttpPostedFileBase filebase=Request.Files[0]; //单独文件访问
Stream inputstream=filebase.InputStream; //获取excel文档流
string filename=filebase.FileName;

Excel文件流转换成datatable

   IWorkbook workbook = new XSSFWorkbook(filestream); //.xlsx
   ISheet sheet=workbook.GetSheetAt(0); 

    DataTable table = new DataTable();

            IRow headerRow = sheet.GetRow(headerRowIndex);

            if (headerRow == null) return table;

            int cellCount = headerRow.LastCellNum;//LastCellNum = PhysicalNumberOfCells
            int rowCount = sheet.LastRowNum;//LastRowNum = PhysicalNumberOfRows - 1

            //handling header(处理标题).
            for (int i = headerRow.FirstCellNum; i < cellCount; i++)
            {
                string headColumnName = GetCellValue(headerRow.GetCell(i));  //GetCellValue()根据Excel列类型获取列的值

                while (table.Columns.Contains(headColumnName)) headColumnName = headColumnName + "+";

                DataColumn column = new DataColumn(headColumnName);
                table.Columns.Add(column);

            }
            for (int i = (sheet.FirstRowNum + 1); i <= rowCount; i++)
            {
                IRow row = sheet.GetRow(i);
                DataRow dataRow = table.NewRow();
                if (row != null && row.FirstCellNum > -1)
                {
                    for (int j = row.FirstCellNum; j < cellCount; j++)
                    {
                        if (row.GetCell(j) != null)
                        {
                            if (dataRow.ItemArray.Length > j)
                            {
                                dataRow[j] = GetCellValue(row.GetCell(j));
                            }
                        }
                    }
                    table.Rows.Add(dataRow);
                }
            }
            return table;