How to add a new sheet to an exising Excel file with EPPlus?

Question

Using EPPlus I want to add a new sheet to an Excel file but I do not want to delete the existing sheets in the file if any, and I want to insert it as the first sheet in the file. Here is what I have written for a quick test but it deletes all the existing sheets:

using (ExcelPackage p = new ExcelPackage())
{
    p.Workbook.Worksheets.Add("HubaHuba");
    p.Workbook.Worksheets.MoveToStart("HubaHuba");
    ExcelWorksheet ws = p.Workbook.Worksheets[1];
    ws.Name = "HubaHuba";

    var cell = ws.Cells[1, 1];
    cell.Value = "dfsdfsdfsd";
    cell = ws.Cells[1, 2];
    cell.Value = "347895y5 Oh";

    Byte[] bin = p.GetAsByteArray();
    File.WriteAllBytes(path,bin);
}

Answer 1

using (ExcelPackage excelEngine = new ExcelPackage())
{
     excelEngine.Workbook.Worksheets.Add("sheet1");
     excelEngine.Workbook.Worksheets.Add("sheet2");
     excelEngine.Workbook.Worksheets.Add("sheet3");

     String myFile= "c:\....\xx.xlsx";
     excelEngine.SaveAs();

}

When you use Add the sheet is added at the and of current file sheets.

If you want to add in a specific position use this function:

excelEngine.Workbook.Worksheets.Add("sheet0");
excelEngine.Workbook.Worksheets.MoveBefore(4, 1);

sheet0 is added at the and in 4th position and you move it in first position with the previous code.

Answer 2

That's because you're rewriting the file with command File.WriteAllBytes. Instead you should just call p.Save() and ExcelPackage needs to use the constructor that accepts the file path. Then it will work.