GetWindowTextLengthW

// USER32.dll  (Unicode / -W)
#include <windows.h>

INT GetWindowTextLengthW(
    HWND hWnd
);

<DllImport("USER32.dll", CharSet:=CharSet.Unicode, SetLastError:=True, ExactSpelling:=True)>
Public Shared Function GetWindowTextLengthW(
    hWnd As IntPtr   ' HWND
) As Integer
End Function

' hWnd : HWND
Declare PtrSafe Function GetWindowTextLengthW Lib "user32" ( _
    ByVal hWnd 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

GetWindowTextLengthW = ctypes.windll.user32.GetWindowTextLengthW
GetWindowTextLengthW.restype = ctypes.c_int
GetWindowTextLengthW.argtypes = [
    wintypes.HANDLE,  # hWnd : HWND
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
GetWindowTextLengthW = Fiddle::Function.new(
  lib['GetWindowTextLengthW'],
  [
    Fiddle::TYPE_VOIDP,  # hWnd : HWND
  ],
  Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "user32")]
extern "system" {
    fn GetWindowTextLengthW(
        hWnd: *mut core::ffi::c_void  // HWND
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("USER32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern int GetWindowTextLengthW(IntPtr hWnd);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_GetWindowTextLengthW' -Namespace Win32 -PassThru
# $api::GetWindowTextLengthW(hWnd)

#uselib "USER32.dll"
#func global GetWindowTextLengthW "GetWindowTextLengthW" wptr
; GetWindowTextLengthW hWnd   ; 戻り値は stat
; hWnd : HWND -> "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 "USER32.dll"
#cfunc global GetWindowTextLengthW "GetWindowTextLengthW" sptr
; res = GetWindowTextLengthW(hWnd)
; hWnd : HWND -> "sptr"

; INT GetWindowTextLengthW(HWND hWnd)
#uselib "USER32.dll"
#cfunc global GetWindowTextLengthW "GetWindowTextLengthW" intptr
; res = GetWindowTextLengthW(hWnd)
; hWnd : HWND -> "intptr"

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procGetWindowTextLengthW = user32.NewProc("GetWindowTextLengthW")
)

// hWnd (HWND)
r1, _, err := procGetWindowTextLengthW.Call(
	uintptr(hWnd),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // INT

function GetWindowTextLengthW(
  hWnd: THandle   // HWND
): Integer; stdcall;
  external 'USER32.dll' name 'GetWindowTextLengthW';

result := DllCall("USER32\GetWindowTextLengthW"
    , "Ptr", hWnd   ; HWND
    , "Int")   ; return: INT

●GetWindowTextLengthW(hWnd) = DLL("USER32.dll", "int GetWindowTextLengthW(void*)")
# 呼び出し: GetWindowTextLengthW(hWnd)
# hWnd : HWND -> "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。