EnumDesktopWindows

// USER32.dll
#include <windows.h>

BOOL EnumDesktopWindows(
    HDESK hDesktop,   // optional
    WNDENUMPROC lpfn,
    LPARAM lParam
);

<DllImport("USER32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function EnumDesktopWindows(
    hDesktop As IntPtr,   ' HDESK optional
    lpfn As IntPtr,   ' WNDENUMPROC
    lParam As IntPtr   ' LPARAM
) As Boolean
End Function

' hDesktop : HDESK optional
' lpfn : WNDENUMPROC
' lParam : LPARAM
Declare PtrSafe Function EnumDesktopWindows Lib "user32" ( _
    ByVal hDesktop As LongPtr, _
    ByVal lpfn As LongPtr, _
    ByVal lParam As LongPtr) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

EnumDesktopWindows = ctypes.windll.user32.EnumDesktopWindows
EnumDesktopWindows.restype = wintypes.BOOL
EnumDesktopWindows.argtypes = [
    wintypes.HANDLE,  # hDesktop : HDESK optional
    ctypes.c_void_p,  # lpfn : WNDENUMPROC
    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')
EnumDesktopWindows = Fiddle::Function.new(
  lib['EnumDesktopWindows'],
  [
    Fiddle::TYPE_VOIDP,  # hDesktop : HDESK optional
    Fiddle::TYPE_VOIDP,  # lpfn : WNDENUMPROC
    Fiddle::TYPE_INTPTR_T,  # lParam : LPARAM
  ],
  Fiddle::TYPE_INT)

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

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("USER32.dll", SetLastError = true)]
public static extern bool EnumDesktopWindows(IntPtr hDesktop, IntPtr lpfn, IntPtr lParam);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_EnumDesktopWindows' -Namespace Win32 -PassThru
# $api::EnumDesktopWindows(hDesktop, lpfn, lParam)

#uselib "USER32.dll"
#func global EnumDesktopWindows "EnumDesktopWindows" sptr, sptr, sptr
; EnumDesktopWindows hDesktop, lpfn, lParam   ; 戻り値は stat
; hDesktop : HDESK optional -> "sptr"
; lpfn : WNDENUMPROC -> "sptr"
; lParam : LPARAM -> "sptr"
; ※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 EnumDesktopWindows "EnumDesktopWindows" sptr, sptr, sptr
; res = EnumDesktopWindows(hDesktop, lpfn, lParam)
; hDesktop : HDESK optional -> "sptr"
; lpfn : WNDENUMPROC -> "sptr"
; lParam : LPARAM -> "sptr"

; BOOL EnumDesktopWindows(HDESK hDesktop, WNDENUMPROC lpfn, LPARAM lParam)
#uselib "USER32.dll"
#cfunc global EnumDesktopWindows "EnumDesktopWindows" intptr, intptr, intptr
; res = EnumDesktopWindows(hDesktop, lpfn, lParam)
; hDesktop : HDESK optional -> "intptr"
; lpfn : WNDENUMPROC -> "intptr"
; lParam : LPARAM -> "intptr"

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

var (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procEnumDesktopWindows = user32.NewProc("EnumDesktopWindows")
)

// hDesktop (HDESK optional), lpfn (WNDENUMPROC), lParam (LPARAM)
r1, _, err := procEnumDesktopWindows.Call(
	uintptr(hDesktop),
	uintptr(lpfn),
	uintptr(lParam),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function EnumDesktopWindows(
  hDesktop: THandle;   // HDESK optional
  lpfn: Pointer;   // WNDENUMPROC
  lParam: NativeInt   // LPARAM
): BOOL; stdcall;
  external 'USER32.dll' name 'EnumDesktopWindows';

result := DllCall("USER32\EnumDesktopWindows"
    , "Ptr", hDesktop   ; HDESK optional
    , "Ptr", lpfn   ; WNDENUMPROC
    , "Ptr", lParam   ; LPARAM
    , "Int")   ; return: BOOL

●EnumDesktopWindows(hDesktop, lpfn, lParam) = DLL("USER32.dll", "bool EnumDesktopWindows(void*, void*, int)")
# 呼び出し: EnumDesktopWindows(hDesktop, lpfn, lParam)
# hDesktop : HDESK optional -> "void*"
# lpfn : WNDENUMPROC -> "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)。