Volatile formulas

[SteveGoodman]

Can anyone help me with writing formulas in C using the Excel SDK.

At present we have about 40 formulas, most of which take about 4 or 5 values and then do SQL searchs on SQL Server, now all these functions/formulas are Volatile, so when in the function paste dialog (fx button) it keeps going away to require the database and thus is very slow.

What we would like to do is make the formulas non-volatile by using the # operator instead of the ! in the type_text, so they will not be continuously updating each time another part of the spreadhseet is changed. However when we make our functions non_volatile we seem to have no way of being able to telling them to go back off to the Database update themseleves. Pressing F9 makes no difference, as Excel belives that the values have not changed, and even closing down and opening up the spreadsheet again has no effect, as Excel still thinks that the values have not changed.

So what we ideally want to be able to do is have a menu option which turns the volatility of the formulas on and off.

Any ideas would be excellent.

Steve

 

[Andrew Poulsom]

I use an Add-In that looks at my financial database. Of course, Excel cannot know if the database has changed. To make them refresh when the workbook is calculated, I think they use a macro to interrupt the F9 key and replace = with =, then do the calculation as normal.

That said, I am surprised that your formulas do not refresh when you open a workbook.

 

[Juan Pablo González]

You can also make another, optional parameter, to tell the function to be Volatile or not.