StringFromGUID2

// OLE32.dll
#include <windows.h>

INT StringFromGUID2(
    const GUID* rguid,
    LPWSTR lpsz,
    INT cchMax
);

<DllImport("OLE32.dll", ExactSpelling:=True)>
Public Shared Function StringFromGUID2(
    ByRef rguid As Guid,   ' GUID*
    <MarshalAs(UnmanagedType.LPWStr)> lpsz As System.Text.StringBuilder,   ' LPWSTR out
    cchMax As Integer   ' INT
) As Integer
End Function

' rguid : GUID*
' lpsz : LPWSTR out
' cchMax : INT
Declare PtrSafe Function StringFromGUID2 Lib "ole32" ( _
    ByVal rguid As LongPtr, _
    ByVal lpsz As LongPtr, _
    ByVal cchMax 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

StringFromGUID2 = ctypes.windll.ole32.StringFromGUID2
StringFromGUID2.restype = ctypes.c_int
StringFromGUID2.argtypes = [
    ctypes.c_void_p,  # rguid : GUID*
    wintypes.LPWSTR,  # lpsz : LPWSTR out
    ctypes.c_int,  # cchMax : INT
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('OLE32.dll')
StringFromGUID2 = Fiddle::Function.new(
  lib['StringFromGUID2'],
  [
    Fiddle::TYPE_VOIDP,  # rguid : GUID*
    Fiddle::TYPE_VOIDP,  # lpsz : LPWSTR out
    Fiddle::TYPE_INT,  # cchMax : INT
  ],
  Fiddle::TYPE_INT)

#[link(name = "ole32")]
extern "system" {
    fn StringFromGUID2(
        rguid: *const GUID,  // GUID*
        lpsz: *mut u16,  // LPWSTR out
        cchMax: i32  // INT
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("OLE32.dll")]
public static extern int StringFromGUID2(ref Guid rguid, [MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder lpsz, int cchMax);
"@
$api = Add-Type -MemberDefinition $sig -Name 'OLE32_StringFromGUID2' -Namespace Win32 -PassThru
# $api::StringFromGUID2(rguid, lpsz, cchMax)

#uselib "OLE32.dll"
#func global StringFromGUID2 "StringFromGUID2" sptr, sptr, sptr
; StringFromGUID2 varptr(rguid), varptr(lpsz), cchMax   ; 戻り値は stat
; rguid : GUID* -> "sptr"
; lpsz : LPWSTR out -> "sptr"
; cchMax : INT -> "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 "OLE32.dll"
#cfunc global StringFromGUID2 "StringFromGUID2" var, var, int
; res = StringFromGUID2(rguid, lpsz, cchMax)
; rguid : GUID* -> "var"
; lpsz : LPWSTR out -> "var"
; cchMax : INT -> "int"
; ※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。

; INT StringFromGUID2(GUID* rguid, LPWSTR lpsz, INT cchMax)
#uselib "OLE32.dll"
#cfunc global StringFromGUID2 "StringFromGUID2" var, var, int
; res = StringFromGUID2(rguid, lpsz, cchMax)
; rguid : GUID* -> "var"
; lpsz : LPWSTR out -> "var"
; cchMax : INT -> "int"
; ※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 (
	ole32 = windows.NewLazySystemDLL("OLE32.dll")
	procStringFromGUID2 = ole32.NewProc("StringFromGUID2")
)

// rguid (GUID*), lpsz (LPWSTR out), cchMax (INT)
r1, _, err := procStringFromGUID2.Call(
	uintptr(rguid),
	uintptr(lpsz),
	uintptr(cchMax),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // INT

function StringFromGUID2(
  rguid: PGUID;   // GUID*
  lpsz: PWideChar;   // LPWSTR out
  cchMax: Integer   // INT
): Integer; stdcall;
  external 'OLE32.dll' name 'StringFromGUID2';

result := DllCall("OLE32\StringFromGUID2"
    , "Ptr", rguid   ; GUID*
    , "Ptr", lpsz   ; LPWSTR out
    , "Int", cchMax   ; INT
    , "Int")   ; return: INT

●StringFromGUID2(rguid, lpsz, cchMax) = DLL("OLE32.dll", "int StringFromGUID2(void*, char*, int)")
# 呼び出し: StringFromGUID2(rguid, lpsz, cchMax)
# rguid : GUID* -> "void*"
# lpsz : LPWSTR out -> "char*"
# cchMax : INT -> "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)。