win32-ffi

win32 api binding for nodejs

Install

npm i win32-ffi/yarn add win32-ffi

Usage

• Since ffi cannot use the macro function of c++ #define, MAKEWPARAM, MAKELPARAM, etc. can only realize the operation of the numbers. For details, please refer to the document of user_macro_fns.ts

export const MAKELONG = (a: number, b: number): number => (a & 0xfff) | ((b & 0xfff) << 16);

---

• ffi cannot force type conversion, so you need to use refType to define the type

c++

MOUSEHOOKSTRUCT* mouse = (MOUSEHOOKSTRUCT*)(lParam)

ts

ffi.Callback(CPP.LRESULT, [CPP.INT, CPP.WPARAM, ref.refType(CPP.MOUSEHOOKSTRUCT)],(nCode: TS.INT, wParam: TS.WPARAM, lParam: TS.RefStruct) => {})

---

Electron

// get system endianness, cast Buffer to decimal
const bufferCastInt32 = function (buf: Buffer): number {
 return os.endianness() == "LE" ? buf.readInt32LE() : buf.readInt32BE();
};

const mainWindow = new BrowserWindow({
 frame: false,
 transparent: true,
 webPreferences: {
  nodeIntegration: true,
  webSecurity: false,
  webviewTag: true,
  sandbox: false,
  enableRemoteModule: true 
 }
});

const decimalHwnd = bufferCastInt32(mainWindow.getNativeWindowHandle());
SetWindowPos(decimalHwnd, 0, 0, 0, 100, 100, CPP.SWP_NOZORDER);

Samples

• Create thread

const { Win32ffi, ffi, CPP, L, NULL } = require('win32-ffi');

const { CreateThread, MessageBoxW } = new Win32ffi().winFns();

const proc = ffi.Callback(CPP.INT, [CPP.PVOID], () => {
 MessageBoxW(0, L("exmpale"), null, CPP.MB_OK | CPP.MB_ICONEXCLAMATION);
});

CreateThread(null, 0, proc, NULL, 0, NULL);

• Create Mouse Hook

const _createMouseHookProc = () => ffi.Callback(CPP.LRESULT, [CPP.INT, CPP.WPARAM, ref.refType(CPP.StructMOUSEHOOKSTRUCT)],
 (nCode: TS.INT, wParam: TS.WPARAM, lParam: TS.RefStruct) => {
  const mouse: TS.MOUSEHOOKSTRUCT = lParam.deref();
  const pt = mouse.pt;
  const { x, y } = pt;
  const currentHwnd = WindowFromPoint(mouse.pt);
  return CallNextHookEx(0, nCode, wParam, lParam); // need overwrite
 }
)

const _mouseHook = SetWindowsHookExW(CPP.WH_MOUSE_LL, this._createMouseHookProc(), 0, 0);
const msg: TS.RefStruct = new CPP.StructMSG();

while (GetMessageW(msg.ref(), 0, 0, 0) && this._trigger) {
 TranslateMessage(msg.ref());
 DispatchMessageW(msg.ref());
}

UnhookWindowsHookEx(_mouseHook);

More Examples

Exmaples

API DOCS

Main Api

• Win32ffi

const win32ffi =new Win32ffi();

win32ffi.user32();
win32ffi.kernel32();

const winFns = win32ffi.winFns(); // include user32 and kernel32

const _createEnumWindowProc = () => ffi.Callback(CPP.BOOL, [CPP.HWND, CPP.LPARAM],
 (hWnd: TS.HWND) => {
 ......
 return true;
});

winFns.EnumWindows(this._createEnumWindowProc(), 0);

• L, _T, TEXT https://docs.microsoft.com/en-us/windows/win32/learnwin32/working-with-strings

const tmp: TS.HWND = FindWindowExW(0, 0, L('progman'), null);

• ref see http://tootallnate.github.io/ref/
• ffi https://www.npmjs.com/package/ffi-napi
• NULL = ref.NULL
• Struct win320ffi provides litte struct e.g StructRECT StructMSG StructMOUSEHOOKSTRUCT... see win_user_struct.ts for more details

import {ref, StructType,CPP} from 'win32-ffi';

const Struct = StructType(ref);

const MSG = Struct({
  hwnd: CPP.HWND,
  message: CPP.UINT,
  wParam: CPP.WPARAM,
  lParam: CPP.LPARAM,
  time: CPP.DWORD,
  pt: CPP.POINT
});
const msg = new MSG();
console.log(msg.ref());

• TS: ts types
• CPP: c++ types that refer to ffi

Warning

• If you can't get the certain C++ parameter types, you can create a file and rewrite this function

overwrite.ts

import { CPP, ref } from 'win32-ffi';
export const customFns = {
 CallNextHookEx: [CPP.LRESULT, [CPP.HHOOK, CPP.INT, CPP.WPARAM, ref.refType(CPP.MOUSEHOOKSTRUCT)]]
};

index.ts

import { customFns } from './overwrite';
Win32ffi.assign({ user32Fns: customFns });

• win32-ffi does not include Comctl32, because almost all macro-defined functions, but you can use SendMessage to achieve, win32ffi provides
• It is impossible to include all win32 api. If there is no prompt, it means you need to define it by yourself. And you can get type details from visual studio.

License

The scripts and documentation in this project are released under the Apache 2.0 License