OpenXML add new row to existing Excel file

Question

I've got lots of XLSX files and I need to append a new row after the last one in the file. I'm using OpenXML and so far I know how to open/create spreadsheet, but my search for adding new rows to existing files returned nothing. Any ideas ?

Answer 1

If all you need to do is add a blank row to the end and you don't care if a row already exists at the row index, then the following should work for you:

    public static void InsertRow(WorksheetPart worksheetPart)
    {
        SheetData sheetData = worksheetPart.Worksheet.GetFirstChild<SheetData>();  
        Row lastRow = sheetData.Elements<Row>().LastOrDefault();
    
        if (lastRow != null)
        {
            sheetData.InsertAfter(new Row() { RowIndex = (lastRow.RowIndex + 1) }, lastRow); 
        }
        else
        {
            sheetData.Insert(new Row() { RowIndex = 0 });
        }
    }

For OpenXML SDK 2.5 (Runtime) v4.0.30319 there is no Insert method, thus use InsertAt as follows:

            ...
        }
        else
        {
            sheetData.InsertAt(new Row() { RowIndex = 0 }, 0);
        }
    }