topic Re: How to Preserve Global Variables in an Archicad 27 Add-On? in Archicad C++ API

How to Preserve Global Variables in an Archicad 27 Add-On?

nishida_jp — Mon, 17 Mar 2025 03:47:44 GMT

I'm developing an add-on using the API in Archicad 27 with Visual C++ 2019 on Windows 10.

The add-on uses global variables to store calculated data in memory. When I run the add-on from the menu, the calculated results are stored in the add-on's memory. However, when I open the menu and run the add-on again, the previously stored values are lost.

How can I prevent this from happening?

Re: How to Preserve Global Variables in an Archicad 27 Add-On?

Ralph Wessel — Mon, 17 Mar 2025 12:12:57 GMT

The default behaviour is for Archicad to unload an add-on from memory when it isn't in use, which will cause any data held by the add-on to be lost. You can prevent an add-on from being unloaded by calling ACAPI_KeepInMemory(true)

Re: How to Preserve Global Variables in an Archicad 27 Add-On?

nishida_jp — Wed, 19 Mar 2025 15:51:31 GMT

I really appreciate your help!

GSErrCode Initialize (void){ //... ACAPI_KeepInMemory(true); return(err); } static GSErrCode MenuCommandHandler (const API_MenuParams *menuParams) { ACAPI_KeepInMemory(true); //... }