Die Grundlagen sind wichtig:
Zitat von
PSDK:
A global hook monitors messages for all threads in the same desktop as the calling thread. [b]A thread-specific hook monitors messages for only an individual thread.[/a] A global hook procedure can be called in the context of any application in the same desktop as the calling thread, so the procedure must be in a separate dynamic-link library (
DLL) module. A thread-specific hook procedure is called only in the context of the associated thread. If an application installs a hook procedure for one of its own threads, the hook procedure can be in either the same module as the rest of the application's code or in a
DLL. If the application installs a hook procedure for a thread of a different application, the procedure must be in a
DLL. For information, see Dynamic-Link Libraries.