问题
On a 64-bit machine:
Can a 64-bit application call a COM server (out proc) which is running in 32-bit process?
What about vice versa? (32 bit app calling 64-bit COM out proc server)
Thanks!
回答1:
The whole point of out-proc COM is that the two processes interact via RPC (usually LRPC), so it doesn't matter at all which bitness each of them has.
We used COM+ surrogate for forcing 32-bit in-proc components into a separate process for the only purpose of consuming them from 64-bit clients many times - with all necessary stuff for marshalling present it works without any effort.
回答2:
This may be relevant MIDL: 64-Bit Porting Guide.
Basically what it says is that if you pass pointer types (IUnknown etc) it's OK but if you cheat by passing a pointer disguised as a DWORD you may face some problems.
来源：https://stackoverflow.com/questions/3148039/com-client-server-cross-64-32-bit-processes