GetLayeredWindowAttributes

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

BOOL GetLayeredWindowAttributes(
    HWND hwnd,
    COLORREF* pcrKey,   // optional
    BYTE* pbAlpha,   // optional
    LAYERED_WINDOW_ATTRIBUTES_FLAGS* pdwFlags   // optional
);

<DllImport("USER32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function GetLayeredWindowAttributes(
    hwnd As IntPtr,   ' HWND
    pcrKey As IntPtr,   ' COLORREF* optional, out
    pbAlpha As IntPtr,   ' BYTE* optional, out
    pdwFlags As IntPtr   ' LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function

' hwnd : HWND
' pcrKey : COLORREF* optional, out
' pbAlpha : BYTE* optional, out
' pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
Declare PtrSafe Function GetLayeredWindowAttributes Lib "user32" ( _
    ByVal hwnd As LongPtr, _
    ByVal pcrKey As LongPtr, _
    ByVal pbAlpha As LongPtr, _
    ByVal pdwFlags As LongPtr) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

GetLayeredWindowAttributes = ctypes.windll.user32.GetLayeredWindowAttributes
GetLayeredWindowAttributes.restype = wintypes.BOOL
GetLayeredWindowAttributes.argtypes = [
    wintypes.HANDLE,  # hwnd : HWND
    ctypes.c_void_p,  # pcrKey : COLORREF* optional, out
    ctypes.POINTER(ctypes.c_ubyte),  # pbAlpha : BYTE* optional, out
    ctypes.c_void_p,  # pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
GetLayeredWindowAttributes = Fiddle::Function.new(
  lib['GetLayeredWindowAttributes'],
  [
    Fiddle::TYPE_VOIDP,  # hwnd : HWND
    Fiddle::TYPE_VOIDP,  # pcrKey : COLORREF* optional, out
    Fiddle::TYPE_VOIDP,  # pbAlpha : BYTE* optional, out
    Fiddle::TYPE_VOIDP,  # pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
  ],
  Fiddle::TYPE_INT)

#[link(name = "user32")]
extern "system" {
    fn GetLayeredWindowAttributes(
        hwnd: *mut core::ffi::c_void,  // HWND
        pcrKey: *mut u32,  // COLORREF* optional, out
        pbAlpha: *mut u8,  // BYTE* optional, out
        pdwFlags: *mut u32  // LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("USER32.dll", SetLastError = true)]
public static extern bool GetLayeredWindowAttributes(IntPtr hwnd, IntPtr pcrKey, IntPtr pbAlpha, IntPtr pdwFlags);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_GetLayeredWindowAttributes' -Namespace Win32 -PassThru
# $api::GetLayeredWindowAttributes(hwnd, pcrKey, pbAlpha, pdwFlags)

#uselib "USER32.dll"
#func global GetLayeredWindowAttributes "GetLayeredWindowAttributes" sptr, sptr, sptr, sptr
; GetLayeredWindowAttributes hwnd, varptr(pcrKey), varptr(pbAlpha), varptr(pdwFlags)   ; 戻り値は stat
; hwnd : HWND -> "sptr"
; pcrKey : COLORREF* optional, out -> "sptr"
; pbAlpha : BYTE* optional, out -> "sptr"
; pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out -> "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。

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

var (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procGetLayeredWindowAttributes = user32.NewProc("GetLayeredWindowAttributes")
)

// hwnd (HWND), pcrKey (COLORREF* optional, out), pbAlpha (BYTE* optional, out), pdwFlags (LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out)
r1, _, err := procGetLayeredWindowAttributes.Call(
	uintptr(hwnd),
	uintptr(pcrKey),
	uintptr(pbAlpha),
	uintptr(pdwFlags),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function GetLayeredWindowAttributes(
  hwnd: THandle;   // HWND
  pcrKey: Pointer;   // COLORREF* optional, out
  pbAlpha: Pointer;   // BYTE* optional, out
  pdwFlags: Pointer   // LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
): BOOL; stdcall;
  external 'USER32.dll' name 'GetLayeredWindowAttributes';

result := DllCall("USER32\GetLayeredWindowAttributes"
    , "Ptr", hwnd   ; HWND
    , "Ptr", pcrKey   ; COLORREF* optional, out
    , "Ptr", pbAlpha   ; BYTE* optional, out
    , "Ptr", pdwFlags   ; LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
    , "Int")   ; return: BOOL

●GetLayeredWindowAttributes(hwnd, pcrKey, pbAlpha, pdwFlags) = DLL("USER32.dll", "bool GetLayeredWindowAttributes(void*, void*, void*, void*)")
# 呼び出し: GetLayeredWindowAttributes(hwnd, pcrKey, pbAlpha, pdwFlags)
# hwnd : HWND -> "void*"
# pcrKey : COLORREF* optional, out -> "void*"
# pbAlpha : BYTE* optional, out -> "void*"
# pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out -> "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)。

const std = @import("std");

extern "user32" fn GetLayeredWindowAttributes(
    hwnd: ?*anyopaque, // HWND
    pcrKey: [*c]u32, // COLORREF* optional, out
    pbAlpha: [*c]u8, // BYTE* optional, out
    pdwFlags: [*c]u32 // LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
) callconv(std.os.windows.WINAPI) i32;

proc GetLayeredWindowAttributes(
    hwnd: pointer,  # HWND
    pcrKey: ptr uint32,  # COLORREF* optional, out
    pbAlpha: ptr uint8,  # BYTE* optional, out
    pdwFlags: ptr uint32  # LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
): int32 {.importc: "GetLayeredWindowAttributes", stdcall, dynlib: "USER32.dll".}

pragma(lib, "user32");
extern(Windows)
int GetLayeredWindowAttributes(
    void* hwnd,   // HWND
    uint* pcrKey,   // COLORREF* optional, out
    ubyte* pbAlpha,   // BYTE* optional, out
    uint* pdwFlags   // LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
);

ccall((:GetLayeredWindowAttributes, "USER32.dll"), stdcall, Int32,
      (Ptr{Cvoid}, Ptr{UInt32}, Ptr{UInt8}, Ptr{UInt32}),
      hwnd, pcrKey, pbAlpha, pdwFlags)
# hwnd : HWND -> Ptr{Cvoid}
# pcrKey : COLORREF* optional, out -> Ptr{UInt32}
# pbAlpha : BYTE* optional, out -> Ptr{UInt8}
# pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out -> Ptr{UInt32}
# stdcall は 32bit のみ意味を持つ(x64 では無視)。

local ffi = require("ffi")
ffi.cdef[[
int32_t GetLayeredWindowAttributes(
    void* hwnd,
    uint32_t* pcrKey,
    uint8_t* pbAlpha,
    uint32_t* pdwFlags);
]]
local user32 = ffi.load("user32")
-- user32.GetLayeredWindowAttributes(hwnd, pcrKey, pbAlpha, pdwFlags)
-- hwnd : HWND
-- pcrKey : COLORREF* optional, out
-- pbAlpha : BYTE* optional, out
-- pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
-- 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。

const koffi = require('koffi');
const lib = koffi.load('USER32.dll');
const GetLayeredWindowAttributes = lib.func('__stdcall', 'GetLayeredWindowAttributes', 'int32_t', ['void *', 'uint32_t *', 'uint8_t *', 'uint32_t *']);
// GetLayeredWindowAttributes(hwnd, pcrKey, pbAlpha, pdwFlags)
// hwnd : HWND -> 'void *'
// pcrKey : COLORREF* optional, out -> 'uint32_t *'
// pbAlpha : BYTE* optional, out -> 'uint8_t *'
// pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out -> 'uint32_t *'
// 出力ポインタは koffi.out(...) で包む。構造体は koffi.struct で定義。

const lib = Deno.dlopen("USER32.dll", {
  GetLayeredWindowAttributes: { parameters: ["pointer", "pointer", "pointer", "pointer"], result: "i32" },
});
// lib.symbols.GetLayeredWindowAttributes(hwnd, pcrKey, pbAlpha, pdwFlags)
// hwnd : HWND -> "pointer"
// pcrKey : COLORREF* optional, out -> "pointer"
// pbAlpha : BYTE* optional, out -> "pointer"
// pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out -> "pointer"
// 文字列引数は "buffer"(NUL 終端のバイト列を Uint8Array で渡す)。
// 値渡し構造体は { struct: [ ...field types... ] } を使用。

<?php
$ffi = FFI::cdef(<<<C
int32_t GetLayeredWindowAttributes(
    void* hwnd,
    uint32_t* pcrKey,
    uint8_t* pbAlpha,
    uint32_t* pdwFlags);
C, "USER32.dll");
// $ffi->GetLayeredWindowAttributes(hwnd, pcrKey, pbAlpha, pdwFlags);
// hwnd : HWND
// pcrKey : COLORREF* optional, out
// pbAlpha : BYTE* optional, out
// pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
// 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。
// WINAPI(stdcall): x64 では呼出規約が統一されるため問題なし。x86 では __stdcall 対応のラッパが必要な場合あり。

import com.sun.jna.*;
import com.sun.jna.ptr.*;
import com.sun.jna.win32.StdCallLibrary;
import com.sun.jna.win32.W32APIOptions;

public interface User32 extends StdCallLibrary {
    User32 INSTANCE = Native.load("user32", User32.class);
    boolean GetLayeredWindowAttributes(
        Pointer hwnd,   // HWND
        IntByReference pcrKey,   // COLORREF* optional, out
        byte[] pbAlpha,   // BYTE* optional, out
        IntByReference pdwFlags   // LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
    );
}

@[Link("user32")]
lib LibUSER32
  fun GetLayeredWindowAttributes = GetLayeredWindowAttributes(
    hwnd : Void*,   # HWND
    pcrKey : UInt32*,   # COLORREF* optional, out
    pbAlpha : UInt8*,   # BYTE* optional, out
    pdwFlags : UInt32*   # LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
  ) : Int32
end
# 構造体/GUID/enum は lib 内に対応する型定義が必要。
# 呼出規約: x64 は規約統一のため OK。x86(32bit)は WINAPI=stdcall だが Crystal の fun に stdcall 付与構文がなく非対応。

import 'dart:ffi';
import 'package:ffi/ffi.dart';

typedef GetLayeredWindowAttributesNative = Int32 Function(Pointer<Void>, Pointer<Uint32>, Pointer<Uint8>, Pointer<Uint32>);
typedef GetLayeredWindowAttributesDart = int Function(Pointer<Void>, Pointer<Uint32>, Pointer<Uint8>, Pointer<Uint32>);
final GetLayeredWindowAttributes = DynamicLibrary.open('USER32.dll')
    .lookupFunction<GetLayeredWindowAttributesNative, GetLayeredWindowAttributesDart>('GetLayeredWindowAttributes');
// hwnd : HWND -> Pointer<Void>
// pcrKey : COLORREF* optional, out -> Pointer<Uint32>
// pbAlpha : BYTE* optional, out -> Pointer<Uint8>
// pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out -> Pointer<Uint32>
// 文字列は package:ffi の "...".toNativeUtf16()/toNativeUtf8() で変換。

{$mode objfpc}{$H+}
function GetLayeredWindowAttributes(
  hwnd: THandle;   // HWND
  pcrKey: Pointer;   // COLORREF* optional, out
  pbAlpha: Pointer;   // BYTE* optional, out
  pdwFlags: Pointer   // LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
): BOOL; stdcall;
  external 'USER32.dll' name 'GetLayeredWindowAttributes';

import Foreign
import Foreign.C.Types
import Foreign.C.String

foreign import stdcall safe "GetLayeredWindowAttributes"
  c_GetLayeredWindowAttributes :: Ptr () -> Ptr Word32 -> Ptr Word8 -> Ptr Word32 -> IO CInt
-- hwnd : HWND -> Ptr ()
-- pcrKey : COLORREF* optional, out -> Ptr Word32
-- pbAlpha : BYTE* optional, out -> Ptr Word8
-- pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out -> Ptr Word32
-- 要 GHC(Windows)。stdcall は x64 では ccall として扱われる。ブロックする API は safe 呼び出し推奨。

open Ctypes
open Foreign

let getlayeredwindowattributes =
  foreign "GetLayeredWindowAttributes"
    ((ptr void) @-> (ptr uint32_t) @-> (ptr uint8_t) @-> (ptr uint32_t) @-> returning int32_t)
(* hwnd : HWND -> (ptr void) *)
(* pcrKey : COLORREF* optional, out -> (ptr uint32_t) *)
(* pbAlpha : BYTE* optional, out -> (ptr uint8_t) *)
(* pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out -> (ptr uint32_t) *)
(* foreign は cdecl 前提。x64 Windows では WINAPI と一致。構造体は ctypes structure を定義のこと。 *)

(cffi:define-foreign-library user32 (t "USER32.dll"))
(cffi:use-foreign-library user32)

(cffi:defcfun ("GetLayeredWindowAttributes" get-layered-window-attributes :convention :stdcall) :int32
  (hwnd :pointer)   ; HWND
  (pcr-key :pointer)   ; COLORREF* optional, out
  (pb-alpha :pointer)   ; BYTE* optional, out
  (pdw-flags :pointer))   ; LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out
; isize/usize(INT_PTR/SIZE_T)は x64 前提で :int64/:uint64。x86 では :int32/:uint32。

use Win32::API;
my $GetLayeredWindowAttributes = Win32::API::More->new('USER32',
    'BOOL GetLayeredWindowAttributes(HANDLE hwnd, LPVOID pcrKey, LPVOID pbAlpha, LPVOID pdwFlags)');
# my $ret = $GetLayeredWindowAttributes->Call($hwnd, $pcrKey, $pbAlpha, $pdwFlags);
# hwnd : HWND -> HANDLE
# pcrKey : COLORREF* optional, out -> LPVOID
# pbAlpha : BYTE* optional, out -> LPVOID
# pdwFlags : LAYERED_WINDOW_ATTRIBUTES_FLAGS* optional, out -> LPVOID
# 値渡し構造体は pack() した文字列、または Win32::API::Struct を使用。