CSHARP

Convert DataTable to excel file c# using epplus

 /// <summary>
        /// Convert DataTable to Excel File
        /// </summary>
        /// <param name="filePath">Excel FilePath</param>
        /// <param name="table">DataTable</param>
        /// <param name="fileName">Excel Filename</param>
        /// <returns></returns>
        public bool Write(string filePath, DataTable table, string fileName)
        {
            try
            {
                bool success = false;
                var today = Convert.ToDateTime(DateTime.Now).ToString("yyyyMMddHHmmss");
                //delete existing files
                // Util_Directory.DeleteFiles(filePath);
                var newDir = filePath + "" + today;
                //if dir not exist create
                Util_Directory.CreateDirectory(newDir);
                FileInfo file = new FileInfo(Path.Combine(newDir, fileName));
                ExcelPackage.LicenseContext = LicenseContext.NonCommercial;
          
                using (var package = new ExcelPackage(file))
                {
                    var workSheet = package.Workbook.Worksheets.Add("Sheet1");
                    //add column headers
                    var columns = table.Columns.Cast<DataColumn>().Select(x => x.ColumnName).ToList();
                    int i = 1;
                    foreach (var column in columns)
                    {
                        workSheet.Cells[1, i].Value = column;
                        i++;
                    }

                    // add row values
                    int startRow = 2;
                    foreach (DataRow row in table.Rows)
                    {
                        int startColumn = 1;
                        foreach (var item in row.ItemArray)
                        {
                            workSheet.Cells[startRow, startColumn].Value = item;
                            startColumn++;
                        }
                        startRow++;
                    }

                    workSheet.Cells.AutoFitColumns();
                    package.Save();
                    success = true;
                }

                return success;
            }
            catch (Exception)
            {
                throw;
            }
        }

convert excel to datatable using epplus

 readonly DataTable dt = new DataTable();
        /// <summary>
        /// Convert excel file to DataTable by xml configuration
        /// </summary>
        /// <param name="xmllFilePath">xml filepath</param>
        /// <param name="excelFilePath">excel filePath</param>
        /// <returns>DataTable</returns>
        public DataTable Read(string xmllFilePath, string excelFilePath)
        {
            try
            {
                List<string> xmlColumns = MiscUtil.ExtractXMLToList(xmllFilePath);
                List<string> xcelColumnNames = new List<string>();

                FileInfo excelFile = new FileInfo(excelFilePath); ;
                ExcelPackage.LicenseContext = LicenseContext.NonCommercial;
                using (ExcelPackage package = new ExcelPackage(excelFile))
                {
                    //get colmuns and store to list 
                    ExcelWorksheet workSheet = package.Workbook.Worksheets[0];
                    {
                        for (int i = 1; i <= workSheet.Dimension.End.Column; i++)
                        {
                            xcelColumnNames.Add(workSheet.Cells[1, i].Value.ToString());
                        }
                    }
                    //get indexes to compare xml and excel columns
                    Dictionary<string, int> indexes = MiscUtil.GetDictionaryOfListArray(xmlColumns, xcelColumnNames.ToArray());
                    //get the match columns and add to datatable columns
                    foreach (var header in indexes)
                    {
                        if (header.Value >= 0)
                        {
                            dt.Columns.Add(header.Key);
                        }
                    }
                    // add rows
                    foreach (ExcelWorksheet workSheetR in package.Workbook.Worksheets)
                    {
                       // int columnCnt = workSheetR.Dimension.End.Column;
                        int rowCnt = workSheetR.Dimension.End.Row;
                        var dicValue = indexes.Select(x => x.Value).ToList();
                        List<int> lstOfMatchColumn = dicValue.FindAll(x => x >= 0);
                        List<string> columns = new List<string>();

                        for (int row = 2; row <= rowCnt; row++)
                        {
                            foreach (var col in lstOfMatchColumn)
                            {
                                columns.Add(workSheetR.Cells[row, col + 1].Value?.ToString().Trim());
                            }

                            string[] columnsArray = MiscUtil.ConvertListToArray(columns);
                            dt.Rows.Add(columnsArray);
                            //clear so it will be new list of columns
                            columns.Clear();
                        }
                    }
                }
                return dt;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }