The Wiert Corner - irregular stream of stuff: jpluimers

It is unwise to pass objects allocated in one framework over a DLL boundary to a different framework.

In the case of Using C dll in delphi return nothing, someone tries to pass an Interface to some memory in the C side over to Delphi.

Unless that interface is COM based, don’t do that!

In a more general way: don’t pass memory allocated on the DLL side over to the client side, no matter what kind of client you have.

From the DLL, either pass simple types, or fill buffers allocated at the client side.

–jeroen

via: Using C dll in delphi return nothing – Stack Overflow.