MsiEnumComponentsW

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

DWORD MsiEnumComponentsW(
    DWORD iComponentIndex,
    LPWSTR lpComponentBuf
);

<DllImport("msi.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function MsiEnumComponentsW(
    iComponentIndex As UInteger,   ' DWORD
    <MarshalAs(UnmanagedType.LPWStr)> lpComponentBuf As System.Text.StringBuilder   ' LPWSTR out
) As UInteger
End Function

' iComponentIndex : DWORD
' lpComponentBuf : LPWSTR out
Declare PtrSafe Function MsiEnumComponentsW Lib "msi" ( _
    ByVal iComponentIndex As Long, _
    ByVal lpComponentBuf 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

MsiEnumComponentsW = ctypes.windll.msi.MsiEnumComponentsW
MsiEnumComponentsW.restype = wintypes.DWORD
MsiEnumComponentsW.argtypes = [
    wintypes.DWORD,  # iComponentIndex : DWORD
    wintypes.LPWSTR,  # lpComponentBuf : LPWSTR out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('msi.dll')
MsiEnumComponentsW = Fiddle::Function.new(
  lib['MsiEnumComponentsW'],
  [
    -Fiddle::TYPE_INT,  # iComponentIndex : DWORD
    Fiddle::TYPE_VOIDP,  # lpComponentBuf : LPWSTR out
  ],
  -Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "msi")]
extern "system" {
    fn MsiEnumComponentsW(
        iComponentIndex: u32,  // DWORD
        lpComponentBuf: *mut u16  // LPWSTR out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("msi.dll", CharSet = CharSet.Unicode)]
public static extern uint MsiEnumComponentsW(uint iComponentIndex, [MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder lpComponentBuf);
"@
$api = Add-Type -MemberDefinition $sig -Name 'msi_MsiEnumComponentsW' -Namespace Win32 -PassThru
# $api::MsiEnumComponentsW(iComponentIndex, lpComponentBuf)

#uselib "msi.dll"
#func global MsiEnumComponentsW "MsiEnumComponentsW" wptr, wptr
; MsiEnumComponentsW iComponentIndex, varptr(lpComponentBuf)   ; 戻り値は stat
; iComponentIndex : DWORD -> "wptr"
; lpComponentBuf : LPWSTR 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 "msi.dll"
#cfunc global MsiEnumComponentsW "MsiEnumComponentsW" int, var
; res = MsiEnumComponentsW(iComponentIndex, lpComponentBuf)
; iComponentIndex : DWORD -> "int"
; lpComponentBuf : LPWSTR 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。

; DWORD MsiEnumComponentsW(DWORD iComponentIndex, LPWSTR lpComponentBuf)
#uselib "msi.dll"
#cfunc global MsiEnumComponentsW "MsiEnumComponentsW" int, var
; res = MsiEnumComponentsW(iComponentIndex, lpComponentBuf)
; iComponentIndex : DWORD -> "int"
; lpComponentBuf : LPWSTR 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 (
	msi = windows.NewLazySystemDLL("msi.dll")
	procMsiEnumComponentsW = msi.NewProc("MsiEnumComponentsW")
)

// iComponentIndex (DWORD), lpComponentBuf (LPWSTR out)
r1, _, err := procMsiEnumComponentsW.Call(
	uintptr(iComponentIndex),
	uintptr(lpComponentBuf),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function MsiEnumComponentsW(
  iComponentIndex: DWORD;   // DWORD
  lpComponentBuf: PWideChar   // LPWSTR out
): DWORD; stdcall;
  external 'msi.dll' name 'MsiEnumComponentsW';

result := DllCall("msi\MsiEnumComponentsW"
    , "UInt", iComponentIndex   ; DWORD
    , "Ptr", lpComponentBuf   ; LPWSTR out
    , "UInt")   ; return: DWORD

●MsiEnumComponentsW(iComponentIndex, lpComponentBuf) = DLL("msi.dll", "dword MsiEnumComponentsW(dword, char*)")
# 呼び出し: MsiEnumComponentsW(iComponentIndex, lpComponentBuf)
# iComponentIndex : DWORD -> "dword"
# lpComponentBuf : LPWSTR out -> "char*"
# 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。