How to Read and Write to OpenXML files from your .NET applications?

Following example shows how to read or write to OpenXML files by using only GemBox.Spreadsheet .NET component.

GemBox.Spreadsheet is a C# / VB.NET component which provides simple and efficient way to read, write, convert and print native Microsoft Excel (XLSX, XLS) and other spreadsheet (ODS, CSV) formats and various document formats (HTML, PDF, XPS) from .NET applications without the need for Microsoft Excel on either the developer or client machines.
GemBox.Spreadsheet Free is free of charge while GemBox.Spreadsheet Professional is a commercial version licensed per developer.
For more information, see GemBox.Spreadsheet features and why GemBox.Spreadsheet outperforms Excel automation.

Example reads OpenXML file, changes the value of the cell “A1” and writes the new file:

C# code:

// Load OpenXML file.
var workbook = ExcelFile.Load("Workbook.xlsx");

// Select active worksheet.
var worksheet = workbook.Worksheets.ActiveWorksheet;

// Change the value of the cell "A1".
worksheet.Cells["A1"].Value = "Hello world!";

// Save the file in OpenXML format.
workbook.Save("NewWorkbook.xlsx");

Visual Basic .NET code:

' Load OpenXML file.
Dim workbook = ExcelFile.Load("Workbook.xlsx")

' Select active worksheet.
Dim worksheet = workbook.Worksheets.ActiveWorksheet

' Change the value of the cell "A1".
worksheet.Cells("A1").Value = "Hello world!"

' Save the file in OpenXML format.
workbook.Save("NewWorkbook.xlsx")