ImmGetCandidateListW

// IMM32.dll  (Unicode / -W)
#include <windows.h>

DWORD ImmGetCandidateListW(
    HIMC param0,
    DWORD deIndex,
    CANDIDATELIST* lpCandList,   // optional
    DWORD dwBufLen
);

<DllImport("IMM32.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function ImmGetCandidateListW(
    param0 As IntPtr,   ' HIMC
    deIndex As UInteger,   ' DWORD
    lpCandList As IntPtr,   ' CANDIDATELIST* optional, out
    dwBufLen As UInteger   ' DWORD
) As UInteger
End Function

' param0 : HIMC
' deIndex : DWORD
' lpCandList : CANDIDATELIST* optional, out
' dwBufLen : DWORD
Declare PtrSafe Function ImmGetCandidateListW Lib "imm32" ( _
    ByVal param0 As LongPtr, _
    ByVal deIndex As Long, _
    ByVal lpCandList As LongPtr, _
    ByVal dwBufLen 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

ImmGetCandidateListW = ctypes.windll.imm32.ImmGetCandidateListW
ImmGetCandidateListW.restype = wintypes.DWORD
ImmGetCandidateListW.argtypes = [
    wintypes.HANDLE,  # param0 : HIMC
    wintypes.DWORD,  # deIndex : DWORD
    ctypes.c_void_p,  # lpCandList : CANDIDATELIST* optional, out
    wintypes.DWORD,  # dwBufLen : DWORD
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('IMM32.dll')
ImmGetCandidateListW = Fiddle::Function.new(
  lib['ImmGetCandidateListW'],
  [
    Fiddle::TYPE_VOIDP,  # param0 : HIMC
    -Fiddle::TYPE_INT,  # deIndex : DWORD
    Fiddle::TYPE_VOIDP,  # lpCandList : CANDIDATELIST* optional, out
    -Fiddle::TYPE_INT,  # dwBufLen : DWORD
  ],
  -Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "imm32")]
extern "system" {
    fn ImmGetCandidateListW(
        param0: *mut core::ffi::c_void,  // HIMC
        deIndex: u32,  // DWORD
        lpCandList: *mut CANDIDATELIST,  // CANDIDATELIST* optional, out
        dwBufLen: u32  // DWORD
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("IMM32.dll", CharSet = CharSet.Unicode)]
public static extern uint ImmGetCandidateListW(IntPtr param0, uint deIndex, IntPtr lpCandList, uint dwBufLen);
"@
$api = Add-Type -MemberDefinition $sig -Name 'IMM32_ImmGetCandidateListW' -Namespace Win32 -PassThru
# $api::ImmGetCandidateListW(param0, deIndex, lpCandList, dwBufLen)

#uselib "IMM32.dll"
#func global ImmGetCandidateListW "ImmGetCandidateListW" wptr, wptr, wptr, wptr
; ImmGetCandidateListW param0, deIndex, varptr(lpCandList), dwBufLen   ; 戻り値は stat
; param0 : HIMC -> "wptr"
; deIndex : DWORD -> "wptr"
; lpCandList : CANDIDATELIST* optional, out -> "wptr"
; dwBufLen : 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 "IMM32.dll"
#cfunc global ImmGetCandidateListW "ImmGetCandidateListW" sptr, int, var, int
; res = ImmGetCandidateListW(param0, deIndex, lpCandList, dwBufLen)
; param0 : HIMC -> "sptr"
; deIndex : DWORD -> "int"
; lpCandList : CANDIDATELIST* optional, out -> "var"
; dwBufLen : 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 ImmGetCandidateListW(HIMC param0, DWORD deIndex, CANDIDATELIST* lpCandList, DWORD dwBufLen)
#uselib "IMM32.dll"
#cfunc global ImmGetCandidateListW "ImmGetCandidateListW" intptr, int, var, int
; res = ImmGetCandidateListW(param0, deIndex, lpCandList, dwBufLen)
; param0 : HIMC -> "intptr"
; deIndex : DWORD -> "int"
; lpCandList : CANDIDATELIST* optional, out -> "var"
; dwBufLen : 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 (
	imm32 = windows.NewLazySystemDLL("IMM32.dll")
	procImmGetCandidateListW = imm32.NewProc("ImmGetCandidateListW")
)

// param0 (HIMC), deIndex (DWORD), lpCandList (CANDIDATELIST* optional, out), dwBufLen (DWORD)
r1, _, err := procImmGetCandidateListW.Call(
	uintptr(param0),
	uintptr(deIndex),
	uintptr(lpCandList),
	uintptr(dwBufLen),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function ImmGetCandidateListW(
  param0: THandle;   // HIMC
  deIndex: DWORD;   // DWORD
  lpCandList: Pointer;   // CANDIDATELIST* optional, out
  dwBufLen: DWORD   // DWORD
): DWORD; stdcall;
  external 'IMM32.dll' name 'ImmGetCandidateListW';

result := DllCall("IMM32\ImmGetCandidateListW"
    , "Ptr", param0   ; HIMC
    , "UInt", deIndex   ; DWORD
    , "Ptr", lpCandList   ; CANDIDATELIST* optional, out
    , "UInt", dwBufLen   ; DWORD
    , "UInt")   ; return: DWORD

●ImmGetCandidateListW(param0, deIndex, lpCandList, dwBufLen) = DLL("IMM32.dll", "dword ImmGetCandidateListW(void*, dword, void*, dword)")
# 呼び出し: ImmGetCandidateListW(param0, deIndex, lpCandList, dwBufLen)
# param0 : HIMC -> "void*"
# deIndex : DWORD -> "dword"
# lpCandList : CANDIDATELIST* optional, out -> "void*"
# dwBufLen : 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。