EnumDesktopsA

// USER32.dll  (ANSI / -A)
#include <windows.h>

BOOL EnumDesktopsA(
    HWINSTA hwinsta,   // optional
    DESKTOPENUMPROCA lpEnumFunc,
    LPARAM lParam
);

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

' hwinsta : HWINSTA optional
' lpEnumFunc : DESKTOPENUMPROCA
' lParam : LPARAM
Declare PtrSafe Function EnumDesktopsA Lib "user32" ( _
    ByVal hwinsta As LongPtr, _
    ByVal lpEnumFunc 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

EnumDesktopsA = ctypes.windll.user32.EnumDesktopsA
EnumDesktopsA.restype = wintypes.BOOL
EnumDesktopsA.argtypes = [
    wintypes.HANDLE,  # hwinsta : HWINSTA optional
    ctypes.c_void_p,  # lpEnumFunc : DESKTOPENUMPROCA
    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')
EnumDesktopsA = Fiddle::Function.new(
  lib['EnumDesktopsA'],
  [
    Fiddle::TYPE_VOIDP,  # hwinsta : HWINSTA optional
    Fiddle::TYPE_VOIDP,  # lpEnumFunc : DESKTOPENUMPROCA
    Fiddle::TYPE_INTPTR_T,  # lParam : LPARAM
  ],
  Fiddle::TYPE_INT)

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

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("USER32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
public static extern bool EnumDesktopsA(IntPtr hwinsta, IntPtr lpEnumFunc, IntPtr lParam);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_EnumDesktopsA' -Namespace Win32 -PassThru
# $api::EnumDesktopsA(hwinsta, lpEnumFunc, lParam)

#uselib "USER32.dll"
#func global EnumDesktopsA "EnumDesktopsA" sptr, sptr, sptr
; EnumDesktopsA hwinsta, lpEnumFunc, lParam   ; 戻り値は stat
; hwinsta : HWINSTA optional -> "sptr"
; lpEnumFunc : DESKTOPENUMPROCA -> "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 EnumDesktopsA "EnumDesktopsA" sptr, sptr, sptr
; res = EnumDesktopsA(hwinsta, lpEnumFunc, lParam)
; hwinsta : HWINSTA optional -> "sptr"
; lpEnumFunc : DESKTOPENUMPROCA -> "sptr"
; lParam : LPARAM -> "sptr"

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

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

var (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procEnumDesktopsA = user32.NewProc("EnumDesktopsA")
)

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

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

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

●EnumDesktopsA(hwinsta, lpEnumFunc, lParam) = DLL("USER32.dll", "bool EnumDesktopsA(void*, void*, int)")
# 呼び出し: EnumDesktopsA(hwinsta, lpEnumFunc, lParam)
# hwinsta : HWINSTA optional -> "void*"
# lpEnumFunc : DESKTOPENUMPROCA -> "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)。