Shared Memory

having allocated a block of memory in one process,
I want to access it in another process. But I don't want
to use mapping file or WM_COPYDATA. How can i?
Thanks.

Refer to Advanced Windows. It is very helpful to you.

If you want to use a variable memory block so that two processes share any data, you'd better use memory-mapped file.
But if you want to use a fixed memory block, you can use shared data section.