Modify excel cell

Question

Good morning, I would like to edit some cells from already existing excell file. I tried use EPPlus and normal OpenXml classes. However I failed. In both situation program w

Answer 1

The problem in both cases is that the modified workbook is not saved back to the stream:

MemoryStream ms = new MemoryStream();
using (FileStream fs = File.OpenRead(@"Path\Test.xlsx"))
using (ExcelPackage excelPackage = new ExcelPackage(fs))
{
    ExcelWorkbook excelWorkBook = excelPackage.Workbook;
    ExcelWorksheet excelWorksheet = excelWorkBook.Worksheets.First();
    excelWorksheet.Cells[1, 1].Value = "Test";
    excelWorksheet.Cells[3, 2].Value = "Test2";
    excelWorksheet.Cells[3, 3].Value = "Test3";

    excelPackage.SaveAs(ms); // This is the important part.
}

ms.Position = 0;
return new FileStreamResult(ms, "application/xlsx")
{
    FileDownloadName = "Tester.xlsx"
};