Step 1: Create new windows form application.

Step 2: In solution explorer right click on References and select Add References. Then Add Reference form will open as follows. In that select .Net tab and add "Microsoft.Office.Interop.Excel" reference.

Step 3: Create windows from like below.

Step 4: Write the following code.

  1. using System;
  2. using System.Windows.Forms;
  3. using Excel = Microsoft.Office.Interop.Excel;
  4. namespace ExecelWithFormula
  5. {
  6. public partial class Form1: Form
  7. {
  8. public Form1()
  9. {
  10. InitializeComponent();
  11. }
  12. private void button1_Click(object sender, EventArgs e)
  13. {
  14. Excel.Application excelApp = new Excel.Application();
  15. Excel.Workbook workbook = null;
  16. Excel.Workbooks workbooks = null;
  17. Excel._Worksheet worksheet = null;
  18. workbooks = excelApp.Workbooks;
  19. workbook = workbooks.Add(1);
  20. worksheet = (Excel.Worksheet) workbook.Sheets[1];
  21. excelApp.Visible = true;
  22. worksheet.Cells[1, 1] = "Value1";
  23. worksheet.Cells[1, 2] = "Value2";
  24. worksheet.Cells[1, 3] = "Addition";
  25. worksheet.Cells[2, 1] = textBox1.Text;
  26. worksheet.Cells[2, 2] = textBox2.Text;
  27. worksheet.Cells[2, 3].Formula = "=SUM(A2,B2)";
  28. }
  29. }
  30. }
Step 5: Run the application.

Step 6: Enter values of value1 and value2 and click on Create Excel

Step 7: Excel will be generated with SUM formula in it.

Step 8 : Then change value1 and value2 and check result.