您正在创建的SetHook方法调用你的回调委托直列。这代表最终将被回收，因为你不保持引用它的任何地方。一旦委托收集垃圾，你不会得到任何更多的回调。

You're creating your callback delegate inline in the SetHook method call. That delegate will eventually get garbage collected, since you're not keeping a reference to it anywhere. And once the delegate is garbage collected, you will not get any more callbacks.

要的是，你需要不断给委托的引用活着，只要挂钩到位prevent（直到你调用UnhookWindowsHookEx）。

To prevent that, you need to keep a reference to the delegate alive as long as the hook is in place (until you call UnhookWindowsHookEx).