Use the SetFormula method in the Worksheet class for specifying the formula. Use the SetArrayFormula method for an array formula. Returning the value of the Formula property provides a string containing the written expression of the formula, for example, SUM(A1:B1).

In code the setting of a formula would look something like this in Visual Basic (for illustration purposes only):

   FpSpread1.ActiveSheet.Cells(2, 0).Formula = "SUM(A1:A10)"

or something like this in C#:

   fpSpread1.ActiveSheet.Cells[2, 0].Formula = "SUM(A1:A10)";

and if added in the cell by the end user:

   =SUM(A1:A10)

In this documentation, where examples are shown, the formula appears as:

   SUM(A1:A10)

or

   SUM(3,4,5) gives the result 12

to express that the result of the formula would display the value of 12 in the cell.

Keep these ways of expressing a formula in mind when looking at the examples in this documentation. Refer to the Assembly Reference for more details on the Formula property and the exact code syntax to use.