如何使用ffi将WinApi函数加载到Node.js中

How to load WinApi functions into Node.js using ffi?

本文关键字：Node js 加载 函数 何使用 ffi WinApi      更新时间：2023-09-26

有一个名为ffi的库，它承诺允许用户加载系统本机库并调用其中的函数。

使用他们的例子，我尝试使用位于User32.dll:中的MessageBox函数

var ref = require('ref');
var ffi = require('ffi');
var Struct = require('ref-struct');
// Define Winapi types according to 
//  https://msdn.microsoft.com/en-us/library/windows/desktop/aa383751%28v=vs.85%29.aspx
var winapi = {};
winapi.void = ref.types.void;
winapi.PVOID = ref.refType(winapi.void);
winapi.HANDLE = winapi.PVOID;
winapi.HWND = winapi.HANDLE;
winapi.WCHAR = ref.types.char;
winapi.LPCWSTR = ref.types.CString;
winapi.UINT = ref.types.uint;
// Try to load message box function as defined in 
//   https://msdn.microsoft.com/en-us/library/windows/desktop/ms645505%28v=vs.85%29.aspx
var current = ffi.Library("user32.dll", {
  'MessageBox': [ 'int', [ winapi.HWND, winapi.LPCWSTR, winapi.LPCWSTR, winapi.UINT ] ]
});
current.MessageBox(0, "sss", "sss", 0);

此操作失败，出现错误：

C:'MYSELF'programing'nodejs'node_modules'ffi'lib'dynamic_library.js:112
    throw new Error('Dynamic Symbol Retrieval Error: ' + this.error())
          ^
Error: Dynamic Symbol Retrieval Error: Win32 error 127
    at DynamicLibrary.get (C:'MYSELF'programing'nodejs'node_modules'ffi'lib'dynamic_library.js:112:11)
    at C:'MYSELF'programing'nodejs'node_modules'ffi'lib'library.js:50:19
    at Array.forEach (native)
    at Object.Library (C:'MYSELF'programing'nodejs'node_modules'ffi'lib'library.js:47:28)
    at Object.<anonymous> (C:'MYSELF'programing'nodejs'ffitest'winapi.js:23:19)
    at Module._compile (module.js:460:26)
    at Object.Module._extensions..js (module.js:478:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Function.Module.runMain (module.js:501:10)

我试图把声明改成一些无稽之谈，但我得到了同样的错误，所以我想这真的是错误的。如何修复它以使其正常工作？我是否指定了不正确的数据类型？

请尝试此操作。

var current = ffi.Library("User32.dll", {
   'MessageBoxA': [ 'int', [ winapi.HWND, winapi.LPCWSTR, winapi.LPCWSTR, winapi.UINT ] ]}
);
current.MessageBoxA(ref.NULL, "sss", "sss", 0);

从技术上讲，这些是LPCSTR字符串，而不是LPCWSTR，因为我们使用的是Ansi，而不是UTF-16

相关文章：