c++ - 请解释一下这篇文章在示例中的实际含义？

Question

If nCode is less than zero, the hook procedure must return the value returned by CallNextHookEx.

If nCode is greater than or equal to zero, and the hook procedure did not process the message, it is highly recommended that you call CallNextHookEx and return the value it returns; otherwise, other applications that have installed WH_MOUSE hooks will not receive hook notifications and may behave incorrectly as a result. If the hook procedure processed the message, it may return a nonzero value to prevent the system from passing the message to the target window procedure.

我找到了 here而且我不擅长英语以及这种 Hook 的东西，但我必须按照要求去做。如果你能用简单的例子向我解释它的实际含义，我真的很感激。请帮助我....谢谢

Answer 1

在伪代码中它的意思大概是这样的:

if (nCode < 0) return CallNextHookEx();
else if (nCode >= 0 && !MsgProcessed) return CallNextHookEx();
else
     return 1;