Calling Windows DLLs from 4Test

Note: The Open Agent supports DLL calling for both 32-bit and 64-bit DLL calls, while the Classic Agent supports DLL calling only for 32-bit calls.

Note: In some versions of Silk Test Classic, you can also use the _cdecl calling convention, although it is not officially supported. The _cdecl calling convention does not work with Silk Test 14.0 or later. Using the _cdecl calling convention might lead to unexpected failures of previously functioning DLL calls when migrating from the Classic Agent to the Open Agent or when upgrading Silk Test Classic to a newer version in which _cdecl does not work. If you are facing such failing DLL calls, ensure that you are using the _stdcall calling convention with the _stdcall naming decoration rules applied. For additional information on the DLL calling conventions, see /Gd, /Gr, /Gv, /Gz (Calling Convention).