GetDCEx

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

HDC GetDCEx(
    HWND hWnd,   // optional
    HRGN hrgnClip,   // optional
    GET_DCX_FLAGS flags
);

<DllImport("USER32.dll", ExactSpelling:=True)>
Public Shared Function GetDCEx(
    hWnd As IntPtr,   ' HWND optional
    hrgnClip As IntPtr,   ' HRGN optional
    flags As UInteger   ' GET_DCX_FLAGS
) As IntPtr
End Function

' hWnd : HWND optional
' hrgnClip : HRGN optional
' flags : GET_DCX_FLAGS
Declare PtrSafe Function GetDCEx Lib "user32" ( _
    ByVal hWnd As LongPtr, _
    ByVal hrgnClip As LongPtr, _
    ByVal flags As Long) As LongPtr
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

GetDCEx = ctypes.windll.user32.GetDCEx
GetDCEx.restype = ctypes.c_void_p
GetDCEx.argtypes = [
    wintypes.HANDLE,  # hWnd : HWND optional
    wintypes.HANDLE,  # hrgnClip : HRGN optional
    wintypes.DWORD,  # flags : GET_DCX_FLAGS
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
GetDCEx = Fiddle::Function.new(
  lib['GetDCEx'],
  [
    Fiddle::TYPE_VOIDP,  # hWnd : HWND optional
    Fiddle::TYPE_VOIDP,  # hrgnClip : HRGN optional
    -Fiddle::TYPE_INT,  # flags : GET_DCX_FLAGS
  ],
  Fiddle::TYPE_VOIDP)

#[link(name = "user32")]
extern "system" {
    fn GetDCEx(
        hWnd: *mut core::ffi::c_void,  // HWND optional
        hrgnClip: *mut core::ffi::c_void,  // HRGN optional
        flags: u32  // GET_DCX_FLAGS
    ) -> *mut core::ffi::c_void;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("USER32.dll")]
public static extern IntPtr GetDCEx(IntPtr hWnd, IntPtr hrgnClip, uint flags);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_GetDCEx' -Namespace Win32 -PassThru
# $api::GetDCEx(hWnd, hrgnClip, flags)

#uselib "USER32.dll"
#func global GetDCEx "GetDCEx" sptr, sptr, sptr
; GetDCEx hWnd, hrgnClip, flags   ; 戻り値は stat
; hWnd : HWND optional -> "sptr"
; hrgnClip : HRGN optional -> "sptr"
; flags : GET_DCX_FLAGS -> "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 GetDCEx "GetDCEx" sptr, sptr, int
; res = GetDCEx(hWnd, hrgnClip, flags)
; hWnd : HWND optional -> "sptr"
; hrgnClip : HRGN optional -> "sptr"
; flags : GET_DCX_FLAGS -> "int"

; HDC GetDCEx(HWND hWnd, HRGN hrgnClip, GET_DCX_FLAGS flags)
#uselib "USER32.dll"
#cfunc global GetDCEx "GetDCEx" intptr, intptr, int
; res = GetDCEx(hWnd, hrgnClip, flags)
; hWnd : HWND optional -> "intptr"
; hrgnClip : HRGN optional -> "intptr"
; flags : GET_DCX_FLAGS -> "int"

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

var (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procGetDCEx = user32.NewProc("GetDCEx")
)

// hWnd (HWND optional), hrgnClip (HRGN optional), flags (GET_DCX_FLAGS)
r1, _, err := procGetDCEx.Call(
	uintptr(hWnd),
	uintptr(hrgnClip),
	uintptr(flags),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HDC

function GetDCEx(
  hWnd: THandle;   // HWND optional
  hrgnClip: THandle;   // HRGN optional
  flags: DWORD   // GET_DCX_FLAGS
): THandle; stdcall;
  external 'USER32.dll' name 'GetDCEx';

result := DllCall("USER32\GetDCEx"
    , "Ptr", hWnd   ; HWND optional
    , "Ptr", hrgnClip   ; HRGN optional
    , "UInt", flags   ; GET_DCX_FLAGS
    , "Ptr")   ; return: HDC

●GetDCEx(hWnd, hrgnClip, flags) = DLL("USER32.dll", "void* GetDCEx(void*, void*, dword)")
# 呼び出し: GetDCEx(hWnd, hrgnClip, flags)
# hWnd : HWND optional -> "void*"
# hrgnClip : HRGN optional -> "void*"
# flags : GET_DCX_FLAGS -> "dword"
# 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)。