Open XML SDK 2.0 - how to update a cell in a spreadsheet?

Question

I want to update a cell in a spreadsheet that is used by a chart, using the Open XML SDK 2.0 (CTP). All the code samples I have found insert new cells. I am struggling with

Answer 1

The Code posted by @CDonner throws some exceptions, i have added some of the code that will take care of code, which throws an Exceptions, here it is

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using DocumentFormat.OpenXml;
using DocumentFormat.OpenXml.Packaging;
using DocumentFormat.OpenXml.Spreadsheet;
using System.Xml;
using System.IO;
using System.Diagnostics;

namespace Application.Model{
public class TempCode
{
    public TempCode()
    {
        UpdateCell("E:/Visual Studio Code/Book1.xlsx", "120", 1, "A");
        UpdateCell("E:/Visual Studio Code/Book1.xlsx", "220", 2, "B");
        UpdateCell("E:/Visual Studio Code/Book1.xlsx", "320", 3, "C");
        UpdateCell("E:/Visual Studio Code/Book1.xlsx", "420", 4, "D");
        UpdateCell("E:/Visual Studio Code/Book1.xlsx", "520", 5, "E");

        ProcessStartInfo startInfo = new ProcessStartInfo("E:/Visual Studio Code/Book1.xlsx");
        startInfo.WindowStyle = ProcessWindowStyle.Normal;
        Process.Start(startInfo);



    }

    public static void UpdateCell(string docName, string text,uint rowIndex, string columnName){
        // Open the document for editing.
        using (SpreadsheetDocument spreadSheet = SpreadsheetDocument.Open(docName, true))
        {
            WorksheetPart worksheetPart = GetWorksheetPartByName(spreadSheet, "Sheet2");
            if (worksheetPart != null)
            {
                Cell cell = GetCell(worksheetPart.Worksheet, columnName, rowIndex);
                cell.CellValue = new CellValue(text);
                cell.DataType = new EnumValue(CellValues.Number);
                // Save the worksheet.
                worksheetPart.Worksheet.Save();
            }
        }

    }

    private static WorksheetPart GetWorksheetPartByName(SpreadsheetDocument document, string sheetName){
        IEnumerable sheets =document.WorkbookPart.Workbook.GetFirstChild().
                        Elements().Where(s => s.Name == sheetName);
        if (sheets.Count() == 0){
            return null;
        }
        string relationshipId = sheets.First().Id.Value;
        WorksheetPart worksheetPart = (WorksheetPart)document.WorkbookPart.GetPartById(relationshipId);
        return worksheetPart;
    }


    private static Cell GetCell(Worksheet worksheet, string columnName, uint rowIndex)
    {
        Row row;
        string cellReference = columnName + rowIndex;
        if (worksheet.Elements().Where(r => r.RowIndex == rowIndex).Count() != 0)
            row = worksheet.GetFirstChild().Elements().Where(r => r.RowIndex == rowIndex).FirstOrDefault();
        else{
            row = new Row() { RowIndex = rowIndex };
            worksheet.Append(row);
        }

        if (row == null)
            return null;

        if (row.Elements().Where(c => c.CellReference.Value == cellReference).Count() > 0) {
            return row.Elements().Where(c => c.CellReference.Value == cellReference).First();
        }
        else{
            Cell refCell = null;
            foreach (Cell cell in row.Elements()){
                if (string.Compare(cell.CellReference.Value, cellReference, true) > 0){
                    refCell = cell;
                    break;
                }
            }
            Cell newCell = new Cell() {
                CellReference = cellReference, 
                StyleIndex = (UInt32Value)1U

            };
            row.InsertBefore(newCell, refCell);
            worksheet.Save();
            return newCell;
        }
    }
}

}