lstrcatW

// KERNEL32.dll  (Unicode / -W)
#include <windows.h>

LPWSTR lstrcatW(
    LPWSTR lpString1,
    LPCWSTR lpString2
);

<DllImport("KERNEL32.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function lstrcatW(
    <MarshalAs(UnmanagedType.LPWStr)> lpString1 As System.Text.StringBuilder,   ' LPWSTR in/out
    <MarshalAs(UnmanagedType.LPWStr)> lpString2 As String   ' LPCWSTR
) As IntPtr
End Function

' lpString1 : LPWSTR in/out
' lpString2 : LPCWSTR
Declare PtrSafe Function lstrcatW Lib "kernel32" ( _
    ByVal lpString1 As LongPtr, _
    ByVal lpString2 As LongPtr) As LongPtr
' 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

lstrcatW = ctypes.windll.kernel32.lstrcatW
lstrcatW.restype = wintypes.LPWSTR
lstrcatW.argtypes = [
    wintypes.LPWSTR,  # lpString1 : LPWSTR in/out
    wintypes.LPCWSTR,  # lpString2 : LPCWSTR
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('KERNEL32.dll')
lstrcatW = Fiddle::Function.new(
  lib['lstrcatW'],
  [
    Fiddle::TYPE_VOIDP,  # lpString1 : LPWSTR in/out
    Fiddle::TYPE_VOIDP,  # lpString2 : LPCWSTR
  ],
  Fiddle::TYPE_VOIDP)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "kernel32")]
extern "system" {
    fn lstrcatW(
        lpString1: *mut u16,  // LPWSTR in/out
        lpString2: *const u16  // LPCWSTR
    ) -> *mut u16;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("KERNEL32.dll", CharSet = CharSet.Unicode)]
public static extern IntPtr lstrcatW([MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder lpString1, [MarshalAs(UnmanagedType.LPWStr)] string lpString2);
"@
$api = Add-Type -MemberDefinition $sig -Name 'KERNEL32_lstrcatW' -Namespace Win32 -PassThru
# $api::lstrcatW(lpString1, lpString2)

#uselib "KERNEL32.dll"
#func global lstrcatW "lstrcatW" wptr, wptr
; lstrcatW varptr(lpString1), lpString2   ; 戻り値は stat
; lpString1 : LPWSTR in/out -> "wptr"
; lpString2 : LPCWSTR -> "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 "KERNEL32.dll"
#cfunc global lstrcatW "lstrcatW" var, wstr
; res = lstrcatW(lpString1, lpString2)
; lpString1 : LPWSTR in/out -> "var"
; lpString2 : LPCWSTR -> "wstr"
; ※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。

; LPWSTR lstrcatW(LPWSTR lpString1, LPCWSTR lpString2)
#uselib "KERNEL32.dll"
#cfunc global lstrcatW "lstrcatW" var, wstr
; res = lstrcatW(lpString1, lpString2)
; lpString1 : LPWSTR in/out -> "var"
; lpString2 : LPCWSTR -> "wstr"
; ※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 (
	kernel32 = windows.NewLazySystemDLL("KERNEL32.dll")
	proclstrcatW = kernel32.NewProc("lstrcatW")
)

// lpString1 (LPWSTR in/out), lpString2 (LPCWSTR)
r1, _, err := proclstrcatW.Call(
	uintptr(lpString1),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(lpString2))),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // LPWSTR

function lstrcatW(
  lpString1: PWideChar;   // LPWSTR in/out
  lpString2: PWideChar   // LPCWSTR
): PWideChar; stdcall;
  external 'KERNEL32.dll' name 'lstrcatW';

result := DllCall("KERNEL32\lstrcatW"
    , "Ptr", lpString1   ; LPWSTR in/out
    , "WStr", lpString2   ; LPCWSTR
    , "Ptr")   ; return: LPWSTR

●lstrcatW(lpString1, lpString2) = DLL("KERNEL32.dll", "char* lstrcatW(char*, char*)")
# 呼び出し: lstrcatW(lpString1, lpString2)
# lpString1 : LPWSTR in/out -> "char*"
# lpString2 : LPCWSTR -> "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。