index.js

var ffi = require('ffi');
var ref = require('ref');
var struct = require('ref-struct');

var winapi = {};
winapi.bool = ref.types.bool;
winapi.int = ref.types.int;
winapi.ulong = ref.types.ulong;
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;

var ACCESS_MASK = ref.types.uint;

var SECURITY_ATTRIBUTES = struct('SECURITY_ATTRIBUTES', {
 'nLength': 'ulong',
 'lpSecurityDescriptor': winapi.PVOID,
 'bInheritHandle': 'bool'
});
var LPSECURITY_ATTRIBUTES = ref.refType(SECURITY_ATTRIBUTES);

var STARTUPINFO = struct('STARTUPINFO', {
  'cb': 'ulong',
  'lpReserved': 'string',
  'lpDesktop': 'string',
  'lpTitle': 'string',
  'dwX': 'ulong',
  'dwY': 'ulong',
  'dwXSize': 'ulong',
  'dwYSize': 'ulong',
  'dwXCountChars': 'ulong',
  'dwYCountChars': 'ulong',
  'dwFillAttribute': 'ulong',
  'dwFlags': 'ulong',
  'wShowWindow': 'short',
  'cbReserved2': 'short',
  'lpReserved2': 'IntPtr',
  'hStdInput': winapi.HWND,
  'hStdOutput': winapi.HWND,
  'hStdError': winapi.HWND
});
var LPSTARTUPINFO = ref.refType(STARTUPINFO);

var kernel32 = ffi.Library('kernel32', {
  'ExpandEnvironmentStringsA': [
    'void', [ 'string', 'string', 'uint' ]
  ],
  'GetCurrentThreadId': [
    'ulong', []
  ],
  'GetLastError': [
    'ulong', []
  ],
  'WinExec': [
    'int32', [ 'string' ]
  ]
});

var user32 = ffi.Library('user32', {
  'CloseDesktop': [
    'bool', [ 'int32' ]
  ],
  'CreateDesktopA': [
    winapi.PVOID, [ 'string', 'string', 'pointer', 'ulong', ACCESS_MASK, LPSECURITY_ATTRIBUTES ]
  ],
  'GetThreadDesktop': [
    winapi.PVOID, [ 'ulong' ]
  ],
  'MessageBoxA': [
    'int32', [ 'int32', 'string', 'string', 'int32' ]
  ],
  'OpenDesktopA': [
    winapi.PVOID, [ 'string', 'ulong', 'bool', ACCESS_MASK ]
  ],
  'OpenInputDesktop': [
    winapi.PVOID, [ 'ulong', 'bool', ACCESS_MASK ]
  ],
  'SetThreadDesktop': [
    'bool', [ winapi.PVOID ]
  ],
  'SwitchDesktop': [
    'bool', [ winapi.PVOID ]
  ],
});

var DESKTOP_SWITCHDESKTOP = 256;
var GENERIC_ALL = 983551;
var MAX_PATH = 260;

var explorer_path = Buffer.alloc(MAX_PATH);
explorer_path.type = ref.types.char;
kernel32.ExpandEnvironmentStringsA("%windir%\\explorer.exe", explorer_path, MAX_PATH-1);
console.log(explorer_path.toString())

var hdeskOriginalThread = user32.GetThreadDesktop(kernel32.GetCurrentThreadId());
var hdeskOriginalInput = user32.OpenInputDesktop(0, false, DESKTOP_SWITCHDESKTOP);

var desktopHandle = user32.OpenDesktopA('lila', 0, false, GENERIC_ALL);
if (desktopHandle == 0)
  desktopHandle = user32.CreateDesktopA('lila', null, null, 0, GENERIC_ALL, null);
console.log("Desktop handle:: ", desktopHandle);

var res1 = user32.SetThreadDesktop(desktopHandle);
console.log("SetThreadDesktop result:: ", res1);

var res2 = user32.SwitchDesktop(desktopHandle);
console.log("SwitchDesktop result:: ", res2);

user32.MessageBoxA(0, "sss", "sss", 0);

var res3 = user32.SwitchDesktop(hdeskOriginalInput);
console.log("SwitchDesktop result:: ", res3);

var res4 = user32.SetThreadDesktop(hdeskOriginalThread);
console.log("SetThreadDesktop result:: ", res4);

/*
console.log('running explorer');
var startup_info = STARTUPINFO();
startup_info.cb = sizeof(startup_info);
                startup_info.lpDesktop = desktop_name;

                //We need to create an explorer.exe in the context of the new desktop for start menu, etc
                CreateProcessA(explorer_path, NULL, NULL, NULL, FALSE, 0, NULL, NULL, &startup_info, &process_info);

*/

var res3 = user32.CloseDesktop(desktopHandle);
console.log("CloseDesktop result:: ", res3);
if (!res3) {
  var res4 = kernel32.GetLastError();
  console.log("Last error code:: ", res4);
}

package.json

{
  "name": "w32a",
  "version": "1.0.0",
  "description": "Demo for win32-api",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "ffi": "github:lxe/node-ffi#node-12",
    "ref": "github:lxe/ref#node-12",
    "ref-struct": "github:lxe/ref-struct#node-12",
    "win32-def": "^3.3.0"
  }
}