How can I call a 32-bit DLL from 64-bit code?

Question

I have some 32-bit DLLs that don\'t have matched 64-bit DLLs. How can I invoke these DLLs from a 64-bit application written in Delphi XE2?

Answer 1

You can use the same exact technique used to call 64 bit dlls from 32 bit code.

See http://cc.embarcadero.com/Item/27667

"Just" make the contrary: run a background 32 bit process, the communicate from your 64 bit process with it using a memory mapped buffer.

But this is definitively not an easy task. You'll have to rewrite some asm code. I wrote some article about how it works.

The out-of-process COM option is perhaps the easiest to implement. Or use a more simple IPC - like WM_COPYDATA message or any other mean. But you'll definitively need another 32 bit process to link to the 32 bit libraries.