Node.js C++ Addon: 监控 Windows 窗口事件

以下是一个简单的 Node.js C++ Addon，它演示如何在 Windows 上使用 'SetWinEventHook' API 来监控窗口事件：

#include <node.h>
#include <v8.h>
#include <windows.h>
#pragma comment(lib, "user32.lib")

using namespace v8;

// 定义事件类型和处理函数
enum EventType {
  EVENT_CREATE,
  EVENT_DESTROY,
  EVENT_FOCUS,
  EVENT_BLUR,
  EVENT_ACTIVATE,
  EVENT_DEACTIVATE
};

void HandleWindowEvent(EventType type, HWND hwnd) {
  // 将事件类型和窗口句柄打印到控制台
  const char* event_type;
  switch (type) {
    case EVENT_CREATE: event_type = "CREATE"; break;
    case EVENT_DESTROY: event_type = "DESTROY"; break;
    case EVENT_FOCUS: event_type = "FOCUS"; break;
    case EVENT_BLUR: event_type = "BLUR"; break;
    case EVENT_ACTIVATE: event_type = "ACTIVATE"; break;
    case EVENT_DEACTIVATE: event_type = "DEACTIVATE"; break;
  }
  printf('%s: %p\n', event_type, hwnd);
}

// 定义事件回调函数
void CALLBACK WindowEventCallback(HWINEVENTHOOK hook, DWORD event, HWND hwnd, LONG idObject, LONG idChild, DWORD dwEventThread, DWORD dwmsEventTime) {
  // 根据事件类型调用处理函数
  switch (event) {
    case EVENT_OBJECT_CREATE: HandleWindowEvent(EVENT_CREATE, hwnd); break;
    case EVENT_OBJECT_DESTROY: HandleWindowEvent(EVENT_DESTROY, hwnd); break;
    case EVENT_OBJECT_FOCUS: HandleWindowEvent(EVENT_FOCUS, hwnd); break;
    case EVENT_OBJECT_BLUR: HandleWindowEvent(EVENT_BLUR, hwnd); break;
    case EVENT_SYSTEM_FOREGROUND: HandleWindowEvent(EVENT_ACTIVATE, hwnd); break;
    case EVENT_SYSTEM_DEACTIVATE: HandleWindowEvent(EVENT_DEACTIVATE, hwnd); break;
  }
}

// 定义Addon的初始化函数
void Init(Handle<Object> exports, Handle<Object> module) {
  // 注册SetWinEventHook API
  HMODULE user32 = LoadLibrary("user32.dll");
  if (user32 == NULL) {
    return;
  }
  typedef HWINEVENTHOOK (WINAPI *SetWinEventHook_t)(DWORD eventMin, DWORD eventMax, HMODULE hmodWinEventProc, WINEVENTPROC lpfnWinEventProc, DWORD idProcess, DWORD idThread, DWORD dwFlags);
  SetWinEventHook_t SetWinEventHook = (SetWinEventHook_t)GetProcAddress(user32, "SetWinEventHook");
  if (SetWinEventHook == NULL) {
    FreeLibrary(user32);
    return;
  }

  // 注册事件处理函数
  HWINEVENTHOOK hook = SetWinEventHook(EVENT_MIN, EVENT_MAX, NULL, WindowEventCallback, 0, 0, WINEVENT_OUTOFCONTEXT);
  if (hook == NULL) {
    FreeLibrary(user32);
    return;
  }

  // 将hook保存到module对象中
  module->Set(String::NewSymbol("hook"), External::New(hook));
}

// 导出Addon
NODE_MODULE(win_event_hook, Init)

在 Node.js 中使用此 Addon：

var addon = require('./build/Release/win_event_hook');

process.on('exit', function() {
  // 释放hook资源
  var hook = addon.hook;
  if (hook) {
    var user32 = require('ffi').Library('user32', {
      'UnhookWinEvent': ['bool', ['pointer']]
    });
    user32.UnhookWinEvent(hook);
  }
});

当 Node.js 应用程序运行时，它将监视 Windows 上所有的窗口事件，并将它们打印到控制台。您可以根据自己的需求修改事件处理函数和回调函数。

本文介绍了如何使用 Node.js C++ Addon 来监控 Windows 窗口事件，并提供了完整的代码示例，帮助开发者在 Node.js 应用程序中轻松实现窗口事件监控功能。