How to fill a sheet of Excel file in OpenXML with a List of any class without any mapping

I need to convert a List of my own class or any class (List<T>) into an Excel sheet of an .xlsx file with OpenXML

Also this has to respect the type of the properties (String and Int for TEXT and NUMBER)

Also need the headers of every column has to be the names of the Properties in my class, with space between the words.

Like:

internal class Lines
{
    public string Tipo_de_Línea { get; set; }

    public long Total { get; set; }

}

returns:

I will post only the sheet information because there is plenty information on how to create the file and adding a sheet.

One method to parse the list and fill the sheet:

 private static SheetData MakeSheetData<T>(List<T> input) {
            //set the row count for header
            int rowCount = 1;
            //create the header
            Row header = new Row();
            //create the row index
            header.RowIndex = (UInt32)1;

            //the sheet itself to return
            SheetData sheetData = new SheetData();

            //properties of class of my list
            PropertyInfo[] properties = typeof(T).GetProperties();

            //column counter
            int colCount = 1;
            //for each property
            foreach (PropertyInfo property in properties)
            {
                //I will create a cell and fill with the name of the property. If the property name is "My_Data" the header of that column will be "My Data"
                Cell headerCell = CreateCell(colCount, rowCount, property.Name.Replace('_',' '));
               
                // append the cell to the row (header row in this case)
                header.AppendChild(headerCell);

                //increments the column count
                colCount++;
            }

            //and now another row...
            rowCount++;

            //dont forget to append my header!
            sheetData.AppendChild(header);

            //for each element in my list, every is pretty the same
            foreach (T fila in input)
            {
                colCount = 1;
                Row newrow = new Row();
                newrow.RowIndex = (UInt32)rowCount;
                foreach (PropertyInfo property in properties)
                {
                    //I will pass here also the name of the property type, to get the "type" of the cell (I'm working only with Text and Number but you can choose whatever you need)
                    Cell newcell = CreateCell(colCount, rowCount, property.GetValue(fila).ToString(),property.PropertyType.Name);
                    newrow.AppendChild(newcell);
                    colCount++;
                }
                sheetData.AppendChild(newrow);
                rowCount++;
            }

            return sheetData;
        }

Another method to create the cell with the respective type, set the reference (A1...B2...) and put the data:

        private static Cell CreateCell(int positionX, int positionY, string data, string propertyType = "String")
        {
            //this only will be for the reference of the cell, coming from my row count and my column count
            int unicode = 64 + positionX;
            char character = (char)unicode;
            Cell newCell = new Cell() { CellReference = character.ToString() + positionY };
        
            //the data itself
            newCell.CellValue = new CellValue(data);

            //I will set the type, default is "string" (text)
            switch (propertyType.ToLower()) {

                //long or int (for my case, is the same, you can specify whatever you want or another type)
                case "int32":
                case "int64":
                    newCell.DataType = new EnumValue<CellValues>(CellValues.Number);
                    break;
//                case "string":
                default:
                    newCell.DataType = new EnumValue<CellValues>(CellValues.String);
                    break;
             
            }

            return newCell;
        }

Usage:

SheetData mysheetData = MakeSheetData(myList);

Add sheetdata:

                    WorksheetPart worksheetPart = workbookpart.AddNewPart<WorksheetPart>();
                    worksheetPart.Worksheet = new Worksheet(mysheetData );
                    Sheet sheet = new Sheet() { Id = myDoc.WorkbookPart.GetIdOfPart(worksheetPart),SheetId = 1,Name = "Name of the sheet"};
                    sheets.Append(sheet);