DdeConnect

// USER32.dll
#include <windows.h>

HCONV DdeConnect(
    DWORD idInst,
    HSZ hszService,
    HSZ hszTopic,
    CONVCONTEXT* pCC   // optional
);

<DllImport("USER32.dll", ExactSpelling:=True)>
Public Shared Function DdeConnect(
    idInst As UInteger,   ' DWORD
    hszService As IntPtr,   ' HSZ
    hszTopic As IntPtr,   ' HSZ
    pCC As IntPtr   ' CONVCONTEXT* optional
) As IntPtr
End Function

' idInst : DWORD
' hszService : HSZ
' hszTopic : HSZ
' pCC : CONVCONTEXT* optional
Declare PtrSafe Function DdeConnect Lib "user32" ( _
    ByVal idInst As Long, _
    ByVal hszService As LongPtr, _
    ByVal hszTopic As LongPtr, _
    ByVal pCC As LongPtr) As LongPtr
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

DdeConnect = ctypes.windll.user32.DdeConnect
DdeConnect.restype = ctypes.c_void_p
DdeConnect.argtypes = [
    wintypes.DWORD,  # idInst : DWORD
    wintypes.HANDLE,  # hszService : HSZ
    wintypes.HANDLE,  # hszTopic : HSZ
    ctypes.c_void_p,  # pCC : CONVCONTEXT* optional
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
DdeConnect = Fiddle::Function.new(
  lib['DdeConnect'],
  [
    -Fiddle::TYPE_INT,  # idInst : DWORD
    Fiddle::TYPE_VOIDP,  # hszService : HSZ
    Fiddle::TYPE_VOIDP,  # hszTopic : HSZ
    Fiddle::TYPE_VOIDP,  # pCC : CONVCONTEXT* optional
  ],
  Fiddle::TYPE_VOIDP)

#[link(name = "user32")]
extern "system" {
    fn DdeConnect(
        idInst: u32,  // DWORD
        hszService: *mut core::ffi::c_void,  // HSZ
        hszTopic: *mut core::ffi::c_void,  // HSZ
        pCC: *mut CONVCONTEXT  // CONVCONTEXT* optional
    ) -> *mut core::ffi::c_void;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("USER32.dll")]
public static extern IntPtr DdeConnect(uint idInst, IntPtr hszService, IntPtr hszTopic, IntPtr pCC);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_DdeConnect' -Namespace Win32 -PassThru
# $api::DdeConnect(idInst, hszService, hszTopic, pCC)

#uselib "USER32.dll"
#func global DdeConnect "DdeConnect" sptr, sptr, sptr, sptr
; DdeConnect idInst, hszService, hszTopic, varptr(pCC)   ; 戻り値は stat
; idInst : DWORD -> "sptr"
; hszService : HSZ -> "sptr"
; hszTopic : HSZ -> "sptr"
; pCC : CONVCONTEXT* optional -> "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 "USER32.dll"
#cfunc global DdeConnect "DdeConnect" int, sptr, sptr, var
; res = DdeConnect(idInst, hszService, hszTopic, pCC)
; idInst : DWORD -> "int"
; hszService : HSZ -> "sptr"
; hszTopic : HSZ -> "sptr"
; pCC : CONVCONTEXT* optional -> "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。

; HCONV DdeConnect(DWORD idInst, HSZ hszService, HSZ hszTopic, CONVCONTEXT* pCC)
#uselib "USER32.dll"
#cfunc global DdeConnect "DdeConnect" int, intptr, intptr, var
; res = DdeConnect(idInst, hszService, hszTopic, pCC)
; idInst : DWORD -> "int"
; hszService : HSZ -> "intptr"
; hszTopic : HSZ -> "intptr"
; pCC : CONVCONTEXT* optional -> "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 (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procDdeConnect = user32.NewProc("DdeConnect")
)

// idInst (DWORD), hszService (HSZ), hszTopic (HSZ), pCC (CONVCONTEXT* optional)
r1, _, err := procDdeConnect.Call(
	uintptr(idInst),
	uintptr(hszService),
	uintptr(hszTopic),
	uintptr(pCC),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HCONV

function DdeConnect(
  idInst: DWORD;   // DWORD
  hszService: THandle;   // HSZ
  hszTopic: THandle;   // HSZ
  pCC: Pointer   // CONVCONTEXT* optional
): THandle; stdcall;
  external 'USER32.dll' name 'DdeConnect';

result := DllCall("USER32\DdeConnect"
    , "UInt", idInst   ; DWORD
    , "Ptr", hszService   ; HSZ
    , "Ptr", hszTopic   ; HSZ
    , "Ptr", pCC   ; CONVCONTEXT* optional
    , "Ptr")   ; return: HCONV

●DdeConnect(idInst, hszService, hszTopic, pCC) = DLL("USER32.dll", "void* DdeConnect(dword, void*, void*, void*)")
# 呼び出し: DdeConnect(idInst, hszService, hszTopic, pCC)
# idInst : DWORD -> "dword"
# hszService : HSZ -> "void*"
# hszTopic : HSZ -> "void*"
# pCC : CONVCONTEXT* optional -> "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)。