EnumDesktopsW

// USER32.dll  (Unicode / -W)
#include <windows.h>

BOOL EnumDesktopsW(
    HWINSTA hwinsta,   // optional
    DESKTOPENUMPROCW lpEnumFunc,
    LPARAM lParam
);

<DllImport("USER32.dll", CharSet:=CharSet.Unicode, SetLastError:=True, ExactSpelling:=True)>
Public Shared Function EnumDesktopsW(
    hwinsta As IntPtr,   ' HWINSTA optional
    lpEnumFunc As IntPtr,   ' DESKTOPENUMPROCW
    lParam As IntPtr   ' LPARAM
) As Boolean
End Function

' hwinsta : HWINSTA optional
' lpEnumFunc : DESKTOPENUMPROCW
' lParam : LPARAM
Declare PtrSafe Function EnumDesktopsW Lib "user32" ( _
    ByVal hwinsta As LongPtr, _
    ByVal lpEnumFunc As LongPtr, _
    ByVal lParam As LongPtr) As Long
' Unicode(W): 文字列は ByVal As LongPtr とし StrPtr(unicodeStr) を渡す
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

EnumDesktopsW = ctypes.windll.user32.EnumDesktopsW
EnumDesktopsW.restype = wintypes.BOOL
EnumDesktopsW.argtypes = [
    wintypes.HANDLE,  # hwinsta : HWINSTA optional
    ctypes.c_void_p,  # lpEnumFunc : DESKTOPENUMPROCW
    ctypes.c_ssize_t,  # lParam : LPARAM
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
EnumDesktopsW = Fiddle::Function.new(
  lib['EnumDesktopsW'],
  [
    Fiddle::TYPE_VOIDP,  # hwinsta : HWINSTA optional
    Fiddle::TYPE_VOIDP,  # lpEnumFunc : DESKTOPENUMPROCW
    Fiddle::TYPE_INTPTR_T,  # lParam : LPARAM
  ],
  Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "user32")]
extern "system" {
    fn EnumDesktopsW(
        hwinsta: *mut core::ffi::c_void,  // HWINSTA optional
        lpEnumFunc: *const core::ffi::c_void,  // DESKTOPENUMPROCW
        lParam: isize  // LPARAM
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("USER32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern bool EnumDesktopsW(IntPtr hwinsta, IntPtr lpEnumFunc, IntPtr lParam);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_EnumDesktopsW' -Namespace Win32 -PassThru
# $api::EnumDesktopsW(hwinsta, lpEnumFunc, lParam)

#uselib "USER32.dll"
#func global EnumDesktopsW "EnumDesktopsW" wptr, wptr, wptr
; EnumDesktopsW hwinsta, lpEnumFunc, lParam   ; 戻り値は stat
; hwinsta : HWINSTA optional -> "wptr"
; lpEnumFunc : DESKTOPENUMPROCW -> "wptr"
; lParam : LPARAM -> "wptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

#uselib "USER32.dll"
#cfunc global EnumDesktopsW "EnumDesktopsW" sptr, sptr, sptr
; res = EnumDesktopsW(hwinsta, lpEnumFunc, lParam)
; hwinsta : HWINSTA optional -> "sptr"
; lpEnumFunc : DESKTOPENUMPROCW -> "sptr"
; lParam : LPARAM -> "sptr"

; BOOL EnumDesktopsW(HWINSTA hwinsta, DESKTOPENUMPROCW lpEnumFunc, LPARAM lParam)
#uselib "USER32.dll"
#cfunc global EnumDesktopsW "EnumDesktopsW" intptr, intptr, intptr
; res = EnumDesktopsW(hwinsta, lpEnumFunc, lParam)
; hwinsta : HWINSTA optional -> "intptr"
; lpEnumFunc : DESKTOPENUMPROCW -> "intptr"
; lParam : LPARAM -> "intptr"

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procEnumDesktopsW = user32.NewProc("EnumDesktopsW")
)

// hwinsta (HWINSTA optional), lpEnumFunc (DESKTOPENUMPROCW), lParam (LPARAM)
r1, _, err := procEnumDesktopsW.Call(
	uintptr(hwinsta),
	uintptr(lpEnumFunc),
	uintptr(lParam),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function EnumDesktopsW(
  hwinsta: THandle;   // HWINSTA optional
  lpEnumFunc: Pointer;   // DESKTOPENUMPROCW
  lParam: NativeInt   // LPARAM
): BOOL; stdcall;
  external 'USER32.dll' name 'EnumDesktopsW';

result := DllCall("USER32\EnumDesktopsW"
    , "Ptr", hwinsta   ; HWINSTA optional
    , "Ptr", lpEnumFunc   ; DESKTOPENUMPROCW
    , "Ptr", lParam   ; LPARAM
    , "Int")   ; return: BOOL

●EnumDesktopsW(hwinsta, lpEnumFunc, lParam) = DLL("USER32.dll", "bool EnumDesktopsW(void*, void*, int)")
# 呼び出し: EnumDesktopsW(hwinsta, lpEnumFunc, lParam)
# hwinsta : HWINSTA optional -> "void*"
# lpEnumFunc : DESKTOPENUMPROCW -> "void*"
# lParam : LPARAM -> "int"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。
# ※-W(Unicode)関数。なでしこ1はANSIのため -A 版の利用を推奨。