Why can't global hooks block system messages

Basic window type registration, creation of windows, information loops and window processes are achieved。

Create hooks in winmain:

Hook = setwindowshookex (wh keyboard ll, (hookproc) lowlvelkeyboardproc, getmodulehandle (null), 0);

The hook process:

Lresult callback lowlevelkeyboardproc(int ncode, wmaram wparam, lparam lparam) {
turn 0;
♪ i'm sorry ♪

The result of the operation is that the book was created successfully, and each key is entered into the hook process, but in practice the key is not blocked, and either the note book or another program can be entered properly. It's assumed that by adding low-level hooks to the notebook, my hooks are lower in priority, and then trying to reset my hooks again, it's still not working。

This is the case with lower-level hooks on keyboards and lower-level hooks on mouse。