CallNextHookEx函数有什么用?
Midi 2000-05-05 10:13:00 g_hLogHook = SetWindowsHookEx(WH_JOURNALRECORD,(HOOKPROC)JournalLogProc,HInstance,0);
HOOKPROC JournalLogProc(int iCode,WPARAM wParam, LPARAM lParam)
{
if (iCode< 0)
return (HOOKPROC)CallNextHookEx(g_hLogHook,iCode,wParam,lParam);
...
和
HOOKPROC JournalLogProc(int iCode,WPARAM wParam, LPARAM lParam)
{
if (iCode< 0) return NULL;
.....
有什么区别。替换后好像什么都没有变!