MsiGetPropertyW

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

DWORD MsiGetPropertyW(
    MSIHANDLE hInstall,
    LPCWSTR szName,
    LPWSTR szValueBuf,   // optional
    DWORD* pcchValueBuf   // optional
);

<DllImport("msi.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function MsiGetPropertyW(
    hInstall As UInteger,   ' MSIHANDLE
    <MarshalAs(UnmanagedType.LPWStr)> szName As String,   ' LPCWSTR
    <MarshalAs(UnmanagedType.LPWStr)> szValueBuf As System.Text.StringBuilder,   ' LPWSTR optional, out
    pcchValueBuf As IntPtr   ' DWORD* optional, in/out
) As UInteger
End Function

' hInstall : MSIHANDLE
' szName : LPCWSTR
' szValueBuf : LPWSTR optional, out
' pcchValueBuf : DWORD* optional, in/out
Declare PtrSafe Function MsiGetPropertyW Lib "msi" ( _
    ByVal hInstall As Long, _
    ByVal szName As LongPtr, _
    ByVal szValueBuf As LongPtr, _
    ByVal pcchValueBuf 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

MsiGetPropertyW = ctypes.windll.msi.MsiGetPropertyW
MsiGetPropertyW.restype = wintypes.DWORD
MsiGetPropertyW.argtypes = [
    wintypes.DWORD,  # hInstall : MSIHANDLE
    wintypes.LPCWSTR,  # szName : LPCWSTR
    wintypes.LPWSTR,  # szValueBuf : LPWSTR optional, out
    ctypes.POINTER(wintypes.DWORD),  # pcchValueBuf : DWORD* optional, in/out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('msi.dll')
MsiGetPropertyW = Fiddle::Function.new(
  lib['MsiGetPropertyW'],
  [
    -Fiddle::TYPE_INT,  # hInstall : MSIHANDLE
    Fiddle::TYPE_VOIDP,  # szName : LPCWSTR
    Fiddle::TYPE_VOIDP,  # szValueBuf : LPWSTR optional, out
    Fiddle::TYPE_VOIDP,  # pcchValueBuf : DWORD* optional, in/out
  ],
  -Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "msi")]
extern "system" {
    fn MsiGetPropertyW(
        hInstall: u32,  // MSIHANDLE
        szName: *const u16,  // LPCWSTR
        szValueBuf: *mut u16,  // LPWSTR optional, out
        pcchValueBuf: *mut u32  // DWORD* optional, in/out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("msi.dll", CharSet = CharSet.Unicode)]
public static extern uint MsiGetPropertyW(uint hInstall, [MarshalAs(UnmanagedType.LPWStr)] string szName, [MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder szValueBuf, IntPtr pcchValueBuf);
"@
$api = Add-Type -MemberDefinition $sig -Name 'msi_MsiGetPropertyW' -Namespace Win32 -PassThru
# $api::MsiGetPropertyW(hInstall, szName, szValueBuf, pcchValueBuf)

#uselib "msi.dll"
#func global MsiGetPropertyW "MsiGetPropertyW" wptr, wptr, wptr, wptr
; MsiGetPropertyW hInstall, szName, varptr(szValueBuf), varptr(pcchValueBuf)   ; 戻り値は stat
; hInstall : MSIHANDLE -> "wptr"
; szName : LPCWSTR -> "wptr"
; szValueBuf : LPWSTR optional, out -> "wptr"
; pcchValueBuf : DWORD* optional, in/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 MsiGetPropertyW "MsiGetPropertyW" int, wstr, var, var
; res = MsiGetPropertyW(hInstall, szName, szValueBuf, pcchValueBuf)
; hInstall : MSIHANDLE -> "int"
; szName : LPCWSTR -> "wstr"
; szValueBuf : LPWSTR optional, out -> "var"
; pcchValueBuf : DWORD* optional, in/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 MsiGetPropertyW(MSIHANDLE hInstall, LPCWSTR szName, LPWSTR szValueBuf, DWORD* pcchValueBuf)
#uselib "msi.dll"
#cfunc global MsiGetPropertyW "MsiGetPropertyW" int, wstr, var, var
; res = MsiGetPropertyW(hInstall, szName, szValueBuf, pcchValueBuf)
; hInstall : MSIHANDLE -> "int"
; szName : LPCWSTR -> "wstr"
; szValueBuf : LPWSTR optional, out -> "var"
; pcchValueBuf : DWORD* optional, in/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")
	procMsiGetPropertyW = msi.NewProc("MsiGetPropertyW")
)

// hInstall (MSIHANDLE), szName (LPCWSTR), szValueBuf (LPWSTR optional, out), pcchValueBuf (DWORD* optional, in/out)
r1, _, err := procMsiGetPropertyW.Call(
	uintptr(hInstall),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(szName))),
	uintptr(szValueBuf),
	uintptr(pcchValueBuf),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function MsiGetPropertyW(
  hInstall: DWORD;   // MSIHANDLE
  szName: PWideChar;   // LPCWSTR
  szValueBuf: PWideChar;   // LPWSTR optional, out
  pcchValueBuf: Pointer   // DWORD* optional, in/out
): DWORD; stdcall;
  external 'msi.dll' name 'MsiGetPropertyW';

result := DllCall("msi\MsiGetPropertyW"
    , "UInt", hInstall   ; MSIHANDLE
    , "WStr", szName   ; LPCWSTR
    , "Ptr", szValueBuf   ; LPWSTR optional, out
    , "Ptr", pcchValueBuf   ; DWORD* optional, in/out
    , "UInt")   ; return: DWORD

●MsiGetPropertyW(hInstall, szName, szValueBuf, pcchValueBuf) = DLL("msi.dll", "dword MsiGetPropertyW(dword, char*, char*, void*)")
# 呼び出し: MsiGetPropertyW(hInstall, szName, szValueBuf, pcchValueBuf)
# hInstall : MSIHANDLE -> "dword"
# szName : LPCWSTR -> "char*"
# szValueBuf : LPWSTR optional, out -> "char*"
# pcchValueBuf : DWORD* optional, in/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。