Node-webkit WinAPI

Question

我正在为Windows开发简单的node-webkit应用程序(Vista，7，…)我需要使用一些WinAPI函数，特别是RegisterHotKey和SendInput，来绑定系统范围的热键并基于此进行击键。node-webkit没有提供这样的API，所以我想使用node-ffi来调用这些函数。

我是WinAPI开发的新手，所以我读过一些MSDN手册，但发现大多数示例都是创建窗口、消息循环、消息处理过程等。所以我不太理解，如何在不创建单独窗口的情况下，正确地实现从node-webkit调用WinAPI？

Node-ffi tutorial没有涵盖这种情况，所以我找到了node Windows库，但它似乎只是通过node来实现应用程序。

有没有办法在不创建windows应用程序的情况下实现本机调用？那么正确的方法是什么呢？

Answer 1

我编写了一个节点脚本，使用ffi、ref和ref-struct模块捕获windows上的热键。由于ffi和ref是本机附加组件，我在让它们在打包的.exe中工作时遇到了一些问题。有关更多信息，请参阅我不久前打开的这个github issue。

不管怎样，下面是代码：

var FFI = require('ffi'),
    ref = require('ref'),
    Struct = require('ref-struct');

/* First, create the necessary data structures that'll be used
   by our windows api calls. */

var pointStruct = Struct({
  'x': 'long',
  'y': 'long'
});

var msgStruct = Struct({
  'hwnd': 'int32',
  'message': 'int32', 
  'wParam': 'int32', 
  'lParam': 'int32', 
  'time': 'int32', 
  'pt': pointStruct
});

var msgStructPtr = ref.refType(msgStruct);

/* Second, register the functions we'd like to use by providing
   their method signatures. */

var user32 = new FFI.Library('user32', {

  'RegisterHotKey': [ 
    'bool', ['int32', 'int', 'int32', 'int32'] 
  ],

  'GetMessageA': [ 
    'bool', [msgStructPtr, 'int32', 'int32', 'int32'] 
  ]

  /* You may prefer to use PeekMessageA which has the same
     signature as GetMessageA, but is non-blocking. I haven't
     tested it, though.

});

/* Third, register your hotkeys. I wanted to control a media player,
   so these keys reflect that. */

var ALT = 0x0001,
    CTRL = 0x0002,
    SHIFT = 0x0004;

var MEDIA_NEXT = 0xB0,
    MEDIA_PREV = 0xB1,
    MEDIA_STOP = 0xB2,
    MEDIA_PLAY_PAUSE = 0xB3,
    MEDIA_LAUNCH = 0xB5;

var PERIOD = 0xBE,
    COMMA = 0xBC,
    EQUAL = 0xBB,
    DIVIDE = 0xBF,
    SQUOTE = 0xDE,
    PAGEUP = 0x21,
    PAGEDOWN = 0x22;

registrations = [];
registrations.push(user32.RegisterHotKey(0, 1, 0, MEDIA_NEXT));
registrations.push(user32.RegisterHotKey(0, 1, 0, MEDIA_PREV));
registrations.push(user32.RegisterHotKey(0, 1, 0, MEDIA_STOP));
registrations.push(user32.RegisterHotKey(0, 1, 0, MEDIA_PLAY_PAUSE));
registrations.push(user32.RegisterHotKey(0, 1, 0, MEDIA_LAUNCH));
registrations.push(user32.RegisterHotKey(0, 1, CTRL, PERIOD));
registrations.push(user32.RegisterHotKey(0, 1, CTRL, COMMA));
registrations.push(user32.RegisterHotKey(0, 1, CTRL, EQUAL));
registrations.push(user32.RegisterHotKey(0, 1, CTRL, DIVIDE));
registrations.push(user32.RegisterHotKey(0, 1, CTRL | ALT, PAGEUP));
registrations.push(user32.RegisterHotKey(0, 1, CTRL | ALT, PAGEDOWN));

// an array of booleans telling us which registrations failed/succeeded
console.log(registrations);

/* Fourth, wait for new hotkey events from the message queue. */

var myMsg = new msgStruct;
while (user32.GetMessageA(myMsg.ref(), 0, 0, 0)) {
    var key = myMsg.lParam >> 16;
    switch (key) {
        case MEDIA_NEXT: console.log('media next'); break;
        case MEDIA_PREV: console.log('media prev'); break;
        case MEDIA_STOP: console.log('media stop'); break;
        case MEDIA_PLAY_PAUSE: console.log('media play/pause'); break;
        case MEDIA_LAUNCH: console.log('media launch'); break;
        case PERIOD: console.log('next'); break;
        case COMMA: console.log('previous'); break;
        case EQUAL: console.log('play/pause'); break;
        case DIVIDE: console.log('info'); break;
        case PAGEUP: console.log('volume up'); break;
        case PAGEDOWN: console.log('volume down'); break;
        default: console.log('undefined hotkey', key, key.toString(16));
    }
}

如果你想让它与node-webkit一起工作，请确保使用nw-gyp构建所有的本机附加组件，并将--target设置为您的node-webkit版本(在我的例子中为0.5.1)：

# Make sure you run this command in the following directories (where the binding.gyp files are):
#  node_modules/ffi/
#  node_modules/ffi/node_modules/ref/
#  node_modules/ref/
$ nw-gyp clean configure --target=v0.5.1 build

查看MSDN文档以了解所使用的方法签名和结构。希望这能有所帮助！

Answer 2

node-ffi的另一种选择是使用iohook npm模块：https://github.com/wilix-team/iohook

Node.js全局键盘和鼠标侦听程序。

这个模块可以通过JavaScript/TypeScript应用程序内外的本地钩子来处理键盘和鼠标事件。

可以在here中找到一些其他的替代方案。(然而，在我看来，其他的就不那么好了；例如，大多数都不再需要维护。)