GetFileTitleW

// COMDLG32.dll  (Unicode / -W)
#include <windows.h>

SHORT GetFileTitleW(
    LPCWSTR param0,
    LPWSTR Buf,
    WORD cchSize
);

<DllImport("COMDLG32.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function GetFileTitleW(
    <MarshalAs(UnmanagedType.LPWStr)> param0 As String,   ' LPCWSTR
    <MarshalAs(UnmanagedType.LPWStr)> Buf As System.Text.StringBuilder,   ' LPWSTR out
    cchSize As UShort   ' WORD
) As Short
End Function

' param0 : LPCWSTR
' Buf : LPWSTR out
' cchSize : WORD
Declare PtrSafe Function GetFileTitleW Lib "comdlg32" ( _
    ByVal param0 As LongPtr, _
    ByVal Buf As LongPtr, _
    ByVal cchSize As Integer) As Integer
' 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

GetFileTitleW = ctypes.windll.comdlg32.GetFileTitleW
GetFileTitleW.restype = ctypes.c_short
GetFileTitleW.argtypes = [
    wintypes.LPCWSTR,  # param0 : LPCWSTR
    wintypes.LPWSTR,  # Buf : LPWSTR out
    ctypes.c_ushort,  # cchSize : WORD
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('COMDLG32.dll')
GetFileTitleW = Fiddle::Function.new(
  lib['GetFileTitleW'],
  [
    Fiddle::TYPE_VOIDP,  # param0 : LPCWSTR
    Fiddle::TYPE_VOIDP,  # Buf : LPWSTR out
    -Fiddle::TYPE_SHORT,  # cchSize : WORD
  ],
  Fiddle::TYPE_SHORT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "comdlg32")]
extern "system" {
    fn GetFileTitleW(
        param0: *const u16,  // LPCWSTR
        Buf: *mut u16,  // LPWSTR out
        cchSize: u16  // WORD
    ) -> i16;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("COMDLG32.dll", CharSet = CharSet.Unicode)]
public static extern short GetFileTitleW([MarshalAs(UnmanagedType.LPWStr)] string param0, [MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder Buf, ushort cchSize);
"@
$api = Add-Type -MemberDefinition $sig -Name 'COMDLG32_GetFileTitleW' -Namespace Win32 -PassThru
# $api::GetFileTitleW(param0, Buf, cchSize)

#uselib "COMDLG32.dll"
#func global GetFileTitleW "GetFileTitleW" wptr, wptr, wptr
; GetFileTitleW param0, varptr(Buf), cchSize   ; 戻り値は stat
; param0 : LPCWSTR -> "wptr"
; Buf : LPWSTR out -> "wptr"
; cchSize : WORD -> "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 "COMDLG32.dll"
#cfunc global GetFileTitleW "GetFileTitleW" wstr, var, int
; res = GetFileTitleW(param0, Buf, cchSize)
; param0 : LPCWSTR -> "wstr"
; Buf : LPWSTR out -> "var"
; cchSize : WORD -> "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。

; SHORT GetFileTitleW(LPCWSTR param0, LPWSTR Buf, WORD cchSize)
#uselib "COMDLG32.dll"
#cfunc global GetFileTitleW "GetFileTitleW" wstr, var, int
; res = GetFileTitleW(param0, Buf, cchSize)
; param0 : LPCWSTR -> "wstr"
; Buf : LPWSTR out -> "var"
; cchSize : WORD -> "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 (
	comdlg32 = windows.NewLazySystemDLL("COMDLG32.dll")
	procGetFileTitleW = comdlg32.NewProc("GetFileTitleW")
)

// param0 (LPCWSTR), Buf (LPWSTR out), cchSize (WORD)
r1, _, err := procGetFileTitleW.Call(
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(param0))),
	uintptr(Buf),
	uintptr(cchSize),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // SHORT

function GetFileTitleW(
  param0: PWideChar;   // LPCWSTR
  Buf: PWideChar;   // LPWSTR out
  cchSize: Word   // WORD
): Smallint; stdcall;
  external 'COMDLG32.dll' name 'GetFileTitleW';

result := DllCall("COMDLG32\GetFileTitleW"
    , "WStr", param0   ; LPCWSTR
    , "Ptr", Buf   ; LPWSTR out
    , "UShort", cchSize   ; WORD
    , "Short")   ; return: SHORT

●GetFileTitleW(param0, Buf, cchSize) = DLL("COMDLG32.dll", "int GetFileTitleW(char*, char*, int)")
# 呼び出し: GetFileTitleW(param0, Buf, cchSize)
# param0 : LPCWSTR -> "char*"
# Buf : LPWSTR out -> "char*"
# cchSize : WORD -> "int"
# 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。