Question

I’m writing a set of functions in c++ which can be called by excel. However, these functions are asynchronous, therefore no immediate return values available. Once a result is available I used a callback function through VBA which update the result to the relevant cell which called the functions.

But, here I’m having circular function calling problem, because when I update the cell. excel automatically call the original function once again. Please help me to get around this problem

Thank You

Answer 1

Without knowing more about the data flow of your program it’s impossible to answer in detail. When are c++ functions called, what data is passed to them and when are you updating the relevant cell?

Regardless, how are you calling the C++ functions? If it’s via VBA, try turning off automatic calculation:

MyWorkSheet.EnableCalculation = False

and then turning it back on at the end of the callback:

MyWorkSheet.EnableCalculation = True