SHQueryInfoKeyW

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

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

<DllImport("SHLWAPI.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function SHQueryInfoKeyW(
    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 SHQueryInfoKeyW Lib "shlwapi" ( _
    ByVal hkey As LongPtr, _
    ByVal pcSubKeys As LongPtr, _
    ByVal pcchMaxSubKeyLen As LongPtr, _
    ByVal pcValues As LongPtr, _
    ByVal pcchMaxValueNameLen 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

SHQueryInfoKeyW = ctypes.windll.shlwapi.SHQueryInfoKeyW
SHQueryInfoKeyW.restype = wintypes.DWORD
SHQueryInfoKeyW.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')
SHQueryInfoKeyW = Fiddle::Function.new(
  lib['SHQueryInfoKeyW'],
  [
    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)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "shlwapi")]
extern "system" {
    fn SHQueryInfoKeyW(
        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.Unicode)]
public static extern uint SHQueryInfoKeyW(IntPtr hkey, IntPtr pcSubKeys, IntPtr pcchMaxSubKeyLen, IntPtr pcValues, IntPtr pcchMaxValueNameLen);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SHLWAPI_SHQueryInfoKeyW' -Namespace Win32 -PassThru
# $api::SHQueryInfoKeyW(hkey, pcSubKeys, pcchMaxSubKeyLen, pcValues, pcchMaxValueNameLen)

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

// hkey (HKEY), pcSubKeys (DWORD* optional, out), pcchMaxSubKeyLen (DWORD* optional, out), pcValues (DWORD* optional, out), pcchMaxValueNameLen (DWORD* optional, out)
r1, _, err := procSHQueryInfoKeyW.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 SHQueryInfoKeyW(
  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 'SHQueryInfoKeyW';

result := DllCall("SHLWAPI\SHQueryInfoKeyW"
    , "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

●SHQueryInfoKeyW(hkey, pcSubKeys, pcchMaxSubKeyLen, pcValues, pcchMaxValueNameLen) = DLL("SHLWAPI.dll", "dword SHQueryInfoKeyW(void*, void*, void*, void*, void*)")
# 呼び出し: SHQueryInfoKeyW(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)。
# ※-W(Unicode)関数。なでしこ1はANSIのため -A 版の利用を推奨。