AMGetErrorTextW

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

DWORD AMGetErrorTextW(
    HRESULT hr,
    LPWSTR pbuffer,
    DWORD MaxLen
);

<DllImport("QUARTZ.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function AMGetErrorTextW(
    hr As Integer,   ' HRESULT
    <MarshalAs(UnmanagedType.LPWStr)> pbuffer As System.Text.StringBuilder,   ' LPWSTR out
    MaxLen As UInteger   ' DWORD
) As UInteger
End Function

' hr : HRESULT
' pbuffer : LPWSTR out
' MaxLen : DWORD
Declare PtrSafe Function AMGetErrorTextW Lib "quartz" ( _
    ByVal hr As Long, _
    ByVal pbuffer As LongPtr, _
    ByVal MaxLen As Long) 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

AMGetErrorTextW = ctypes.windll.quartz.AMGetErrorTextW
AMGetErrorTextW.restype = wintypes.DWORD
AMGetErrorTextW.argtypes = [
    ctypes.c_int,  # hr : HRESULT
    wintypes.LPWSTR,  # pbuffer : LPWSTR out
    wintypes.DWORD,  # MaxLen : DWORD
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('QUARTZ.dll')
AMGetErrorTextW = Fiddle::Function.new(
  lib['AMGetErrorTextW'],
  [
    Fiddle::TYPE_INT,  # hr : HRESULT
    Fiddle::TYPE_VOIDP,  # pbuffer : LPWSTR out
    -Fiddle::TYPE_INT,  # MaxLen : DWORD
  ],
  -Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "quartz")]
extern "system" {
    fn AMGetErrorTextW(
        hr: i32,  // HRESULT
        pbuffer: *mut u16,  // LPWSTR out
        MaxLen: u32  // DWORD
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("QUARTZ.dll", CharSet = CharSet.Unicode)]
public static extern uint AMGetErrorTextW(int hr, [MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder pbuffer, uint MaxLen);
"@
$api = Add-Type -MemberDefinition $sig -Name 'QUARTZ_AMGetErrorTextW' -Namespace Win32 -PassThru
# $api::AMGetErrorTextW(hr, pbuffer, MaxLen)

#uselib "QUARTZ.dll"
#func global AMGetErrorTextW "AMGetErrorTextW" wptr, wptr, wptr
; AMGetErrorTextW hr, varptr(pbuffer), MaxLen   ; 戻り値は stat
; hr : HRESULT -> "wptr"
; pbuffer : LPWSTR out -> "wptr"
; MaxLen : DWORD -> "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 "QUARTZ.dll"
#cfunc global AMGetErrorTextW "AMGetErrorTextW" int, var, int
; res = AMGetErrorTextW(hr, pbuffer, MaxLen)
; hr : HRESULT -> "int"
; pbuffer : LPWSTR out -> "var"
; MaxLen : DWORD -> "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。

; DWORD AMGetErrorTextW(HRESULT hr, LPWSTR pbuffer, DWORD MaxLen)
#uselib "QUARTZ.dll"
#cfunc global AMGetErrorTextW "AMGetErrorTextW" int, var, int
; res = AMGetErrorTextW(hr, pbuffer, MaxLen)
; hr : HRESULT -> "int"
; pbuffer : LPWSTR out -> "var"
; MaxLen : DWORD -> "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 (
	quartz = windows.NewLazySystemDLL("QUARTZ.dll")
	procAMGetErrorTextW = quartz.NewProc("AMGetErrorTextW")
)

// hr (HRESULT), pbuffer (LPWSTR out), MaxLen (DWORD)
r1, _, err := procAMGetErrorTextW.Call(
	uintptr(hr),
	uintptr(pbuffer),
	uintptr(MaxLen),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function AMGetErrorTextW(
  hr: Integer;   // HRESULT
  pbuffer: PWideChar;   // LPWSTR out
  MaxLen: DWORD   // DWORD
): DWORD; stdcall;
  external 'QUARTZ.dll' name 'AMGetErrorTextW';

result := DllCall("QUARTZ\AMGetErrorTextW"
    , "Int", hr   ; HRESULT
    , "Ptr", pbuffer   ; LPWSTR out
    , "UInt", MaxLen   ; DWORD
    , "UInt")   ; return: DWORD

●AMGetErrorTextW(hr, pbuffer, MaxLen) = DLL("QUARTZ.dll", "dword AMGetErrorTextW(int, char*, dword)")
# 呼び出し: AMGetErrorTextW(hr, pbuffer, MaxLen)
# hr : HRESULT -> "int"
# pbuffer : LPWSTR out -> "char*"
# MaxLen : DWORD -> "dword"
# 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。