SHEnumKeyExA

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

WIN32_ERROR SHEnumKeyExA(
    HKEY hkey,
    DWORD dwIndex,
    LPSTR pszName,
    DWORD* pcchName
);

<DllImport("SHLWAPI.dll", CharSet:=CharSet.Ansi, ExactSpelling:=True)>
Public Shared Function SHEnumKeyExA(
    hkey As IntPtr,   ' HKEY
    dwIndex As UInteger,   ' DWORD
    <MarshalAs(UnmanagedType.LPStr)> pszName As System.Text.StringBuilder,   ' LPSTR out
    ByRef pcchName As UInteger   ' DWORD* in/out
) As UInteger
End Function

' hkey : HKEY
' dwIndex : DWORD
' pszName : LPSTR out
' pcchName : DWORD* in/out
Declare PtrSafe Function SHEnumKeyExA Lib "shlwapi" ( _
    ByVal hkey As LongPtr, _
    ByVal dwIndex As Long, _
    ByVal pszName As String, _
    ByRef pcchName As Long) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

SHEnumKeyExA = ctypes.windll.shlwapi.SHEnumKeyExA
SHEnumKeyExA.restype = wintypes.DWORD
SHEnumKeyExA.argtypes = [
    wintypes.HANDLE,  # hkey : HKEY
    wintypes.DWORD,  # dwIndex : DWORD
    wintypes.LPSTR,  # pszName : LPSTR out
    ctypes.POINTER(wintypes.DWORD),  # pcchName : DWORD* in/out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('SHLWAPI.dll')
SHEnumKeyExA = Fiddle::Function.new(
  lib['SHEnumKeyExA'],
  [
    Fiddle::TYPE_VOIDP,  # hkey : HKEY
    -Fiddle::TYPE_INT,  # dwIndex : DWORD
    Fiddle::TYPE_VOIDP,  # pszName : LPSTR out
    Fiddle::TYPE_VOIDP,  # pcchName : DWORD* in/out
  ],
  -Fiddle::TYPE_INT)

#[link(name = "shlwapi")]
extern "system" {
    fn SHEnumKeyExA(
        hkey: *mut core::ffi::c_void,  // HKEY
        dwIndex: u32,  // DWORD
        pszName: *mut u8,  // LPSTR out
        pcchName: *mut u32  // DWORD* in/out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("SHLWAPI.dll", CharSet = CharSet.Ansi)]
public static extern uint SHEnumKeyExA(IntPtr hkey, uint dwIndex, [MarshalAs(UnmanagedType.LPStr)] System.Text.StringBuilder pszName, ref uint pcchName);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SHLWAPI_SHEnumKeyExA' -Namespace Win32 -PassThru
# $api::SHEnumKeyExA(hkey, dwIndex, pszName, pcchName)

#uselib "SHLWAPI.dll"
#func global SHEnumKeyExA "SHEnumKeyExA" sptr, sptr, sptr, sptr
; SHEnumKeyExA hkey, dwIndex, varptr(pszName), varptr(pcchName)   ; 戻り値は stat
; hkey : HKEY -> "sptr"
; dwIndex : DWORD -> "sptr"
; pszName : LPSTR out -> "sptr"
; pcchName : DWORD* in/out -> "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 "SHLWAPI.dll"
#cfunc global SHEnumKeyExA "SHEnumKeyExA" sptr, int, var, var
; res = SHEnumKeyExA(hkey, dwIndex, pszName, pcchName)
; hkey : HKEY -> "sptr"
; dwIndex : DWORD -> "int"
; pszName : LPSTR out -> "var"
; pcchName : DWORD* in/out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

; WIN32_ERROR SHEnumKeyExA(HKEY hkey, DWORD dwIndex, LPSTR pszName, DWORD* pcchName)
#uselib "SHLWAPI.dll"
#cfunc global SHEnumKeyExA "SHEnumKeyExA" intptr, int, var, var
; res = SHEnumKeyExA(hkey, dwIndex, pszName, pcchName)
; hkey : HKEY -> "intptr"
; dwIndex : DWORD -> "int"
; pszName : LPSTR out -> "var"
; pcchName : DWORD* in/out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

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

var (
	shlwapi = windows.NewLazySystemDLL("SHLWAPI.dll")
	procSHEnumKeyExA = shlwapi.NewProc("SHEnumKeyExA")
)

// hkey (HKEY), dwIndex (DWORD), pszName (LPSTR out), pcchName (DWORD* in/out)
r1, _, err := procSHEnumKeyExA.Call(
	uintptr(hkey),
	uintptr(dwIndex),
	uintptr(pszName),
	uintptr(pcchName),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // WIN32_ERROR

function SHEnumKeyExA(
  hkey: THandle;   // HKEY
  dwIndex: DWORD;   // DWORD
  pszName: PAnsiChar;   // LPSTR out
  pcchName: Pointer   // DWORD* in/out
): DWORD; stdcall;
  external 'SHLWAPI.dll' name 'SHEnumKeyExA';

result := DllCall("SHLWAPI\SHEnumKeyExA"
    , "Ptr", hkey   ; HKEY
    , "UInt", dwIndex   ; DWORD
    , "Ptr", pszName   ; LPSTR out
    , "Ptr", pcchName   ; DWORD* in/out
    , "UInt")   ; return: WIN32_ERROR

●SHEnumKeyExA(hkey, dwIndex, pszName, pcchName) = DLL("SHLWAPI.dll", "dword SHEnumKeyExA(void*, dword, char*, void*)")
# 呼び出し: SHEnumKeyExA(hkey, dwIndex, pszName, pcchName)
# hkey : HKEY -> "void*"
# dwIndex : DWORD -> "dword"
# pszName : LPSTR out -> "char*"
# pcchName : DWORD* in/out -> "void*"
# 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)。