SHQueryInfoKeyA

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

WIN32_ERROR SHQueryInfoKeyA(
    HKEY hkey,
    DWORD* pcSubKeys,   // optional
    DWORD* pcchMaxSubKeyLen,   // optional
    DWORD* pcValues,   // optional
    DWORD* pcchMaxValueNameLen   // optional
);

<DllImport("SHLWAPI.dll", CharSet:=CharSet.Ansi, ExactSpelling:=True)>
Public Shared Function SHQueryInfoKeyA(
    hkey As IntPtr,   ' HKEY
    pcSubKeys As IntPtr,   ' DWORD* optional, out
    pcchMaxSubKeyLen As IntPtr,   ' DWORD* optional, out
    pcValues As IntPtr,   ' DWORD* optional, out
    pcchMaxValueNameLen As IntPtr   ' DWORD* optional, out
) As UInteger
End Function

' hkey : HKEY
' pcSubKeys : DWORD* optional, out
' pcchMaxSubKeyLen : DWORD* optional, out
' pcValues : DWORD* optional, out
' pcchMaxValueNameLen : DWORD* optional, out
Declare PtrSafe Function SHQueryInfoKeyA Lib "shlwapi" ( _
    ByVal hkey As LongPtr, _
    ByVal pcSubKeys As LongPtr, _
    ByVal pcchMaxSubKeyLen As LongPtr, _
    ByVal pcValues As LongPtr, _
    ByVal pcchMaxValueNameLen 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

SHQueryInfoKeyA = ctypes.windll.shlwapi.SHQueryInfoKeyA
SHQueryInfoKeyA.restype = wintypes.DWORD
SHQueryInfoKeyA.argtypes = [
    wintypes.HANDLE,  # hkey : HKEY
    ctypes.POINTER(wintypes.DWORD),  # pcSubKeys : DWORD* optional, out
    ctypes.POINTER(wintypes.DWORD),  # pcchMaxSubKeyLen : DWORD* optional, out
    ctypes.POINTER(wintypes.DWORD),  # pcValues : DWORD* optional, out
    ctypes.POINTER(wintypes.DWORD),  # pcchMaxValueNameLen : DWORD* optional, out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('SHLWAPI.dll')
SHQueryInfoKeyA = Fiddle::Function.new(
  lib['SHQueryInfoKeyA'],
  [
    Fiddle::TYPE_VOIDP,  # hkey : HKEY
    Fiddle::TYPE_VOIDP,  # pcSubKeys : DWORD* optional, out
    Fiddle::TYPE_VOIDP,  # pcchMaxSubKeyLen : DWORD* optional, out
    Fiddle::TYPE_VOIDP,  # pcValues : DWORD* optional, out
    Fiddle::TYPE_VOIDP,  # pcchMaxValueNameLen : DWORD* optional, out
  ],
  -Fiddle::TYPE_INT)

#[link(name = "shlwapi")]
extern "system" {
    fn SHQueryInfoKeyA(
        hkey: *mut core::ffi::c_void,  // HKEY
        pcSubKeys: *mut u32,  // DWORD* optional, out
        pcchMaxSubKeyLen: *mut u32,  // DWORD* optional, out
        pcValues: *mut u32,  // DWORD* optional, out
        pcchMaxValueNameLen: *mut u32  // DWORD* optional, out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("SHLWAPI.dll", CharSet = CharSet.Ansi)]
public static extern uint SHQueryInfoKeyA(IntPtr hkey, IntPtr pcSubKeys, IntPtr pcchMaxSubKeyLen, IntPtr pcValues, IntPtr pcchMaxValueNameLen);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SHLWAPI_SHQueryInfoKeyA' -Namespace Win32 -PassThru
# $api::SHQueryInfoKeyA(hkey, pcSubKeys, pcchMaxSubKeyLen, pcValues, pcchMaxValueNameLen)

#uselib "SHLWAPI.dll"
#func global SHQueryInfoKeyA "SHQueryInfoKeyA" sptr, sptr, sptr, sptr, sptr
; SHQueryInfoKeyA hkey, varptr(pcSubKeys), varptr(pcchMaxSubKeyLen), varptr(pcValues), varptr(pcchMaxValueNameLen)   ; 戻り値は stat
; hkey : HKEY -> "sptr"
; pcSubKeys : DWORD* optional, out -> "sptr"
; pcchMaxSubKeyLen : DWORD* optional, out -> "sptr"
; pcValues : DWORD* optional, out -> "sptr"
; pcchMaxValueNameLen : DWORD* optional, 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 SHQueryInfoKeyA "SHQueryInfoKeyA" sptr, var, var, var, var
; res = SHQueryInfoKeyA(hkey, pcSubKeys, pcchMaxSubKeyLen, pcValues, pcchMaxValueNameLen)
; hkey : HKEY -> "sptr"
; pcSubKeys : DWORD* optional, out -> "var"
; pcchMaxSubKeyLen : DWORD* optional, out -> "var"
; pcValues : DWORD* optional, out -> "var"
; pcchMaxValueNameLen : DWORD* optional, 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 SHQueryInfoKeyA(HKEY hkey, DWORD* pcSubKeys, DWORD* pcchMaxSubKeyLen, DWORD* pcValues, DWORD* pcchMaxValueNameLen)
#uselib "SHLWAPI.dll"
#cfunc global SHQueryInfoKeyA "SHQueryInfoKeyA" intptr, var, var, var, var
; res = SHQueryInfoKeyA(hkey, pcSubKeys, pcchMaxSubKeyLen, pcValues, pcchMaxValueNameLen)
; hkey : HKEY -> "intptr"
; pcSubKeys : DWORD* optional, out -> "var"
; pcchMaxSubKeyLen : DWORD* optional, out -> "var"
; pcValues : DWORD* optional, out -> "var"
; pcchMaxValueNameLen : DWORD* optional, 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")
	procSHQueryInfoKeyA = shlwapi.NewProc("SHQueryInfoKeyA")
)

// hkey (HKEY), pcSubKeys (DWORD* optional, out), pcchMaxSubKeyLen (DWORD* optional, out), pcValues (DWORD* optional, out), pcchMaxValueNameLen (DWORD* optional, out)
r1, _, err := procSHQueryInfoKeyA.Call(
	uintptr(hkey),
	uintptr(pcSubKeys),
	uintptr(pcchMaxSubKeyLen),
	uintptr(pcValues),
	uintptr(pcchMaxValueNameLen),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // WIN32_ERROR

function SHQueryInfoKeyA(
  hkey: THandle;   // HKEY
  pcSubKeys: Pointer;   // DWORD* optional, out
  pcchMaxSubKeyLen: Pointer;   // DWORD* optional, out
  pcValues: Pointer;   // DWORD* optional, out
  pcchMaxValueNameLen: Pointer   // DWORD* optional, out
): DWORD; stdcall;
  external 'SHLWAPI.dll' name 'SHQueryInfoKeyA';

result := DllCall("SHLWAPI\SHQueryInfoKeyA"
    , "Ptr", hkey   ; HKEY
    , "Ptr", pcSubKeys   ; DWORD* optional, out
    , "Ptr", pcchMaxSubKeyLen   ; DWORD* optional, out
    , "Ptr", pcValues   ; DWORD* optional, out
    , "Ptr", pcchMaxValueNameLen   ; DWORD* optional, out
    , "UInt")   ; return: WIN32_ERROR

●SHQueryInfoKeyA(hkey, pcSubKeys, pcchMaxSubKeyLen, pcValues, pcchMaxValueNameLen) = DLL("SHLWAPI.dll", "dword SHQueryInfoKeyA(void*, void*, void*, void*, void*)")
# 呼び出し: SHQueryInfoKeyA(hkey, pcSubKeys, pcchMaxSubKeyLen, pcValues, pcchMaxValueNameLen)
# hkey : HKEY -> "void*"
# pcSubKeys : DWORD* optional, out -> "void*"
# pcchMaxSubKeyLen : DWORD* optional, out -> "void*"
# pcValues : DWORD* optional, out -> "void*"
# pcchMaxValueNameLen : DWORD* optional, 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)。