OpenClipboard

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

BOOL OpenClipboard(
    HWND hWndNewOwner   // optional
);

<DllImport("USER32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function OpenClipboard(
    hWndNewOwner As IntPtr   ' HWND optional
) As Boolean
End Function

' hWndNewOwner : HWND optional
Declare PtrSafe Function OpenClipboard Lib "user32" ( _
    ByVal hWndNewOwner 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

OpenClipboard = ctypes.windll.user32.OpenClipboard
OpenClipboard.restype = wintypes.BOOL
OpenClipboard.argtypes = [
    wintypes.HANDLE,  # hWndNewOwner : HWND optional
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
OpenClipboard = Fiddle::Function.new(
  lib['OpenClipboard'],
  [
    Fiddle::TYPE_VOIDP,  # hWndNewOwner : HWND optional
  ],
  Fiddle::TYPE_INT)

#[link(name = "user32")]
extern "system" {
    fn OpenClipboard(
        hWndNewOwner: *mut core::ffi::c_void  // HWND optional
    ) -> 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 OpenClipboard(IntPtr hWndNewOwner);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_OpenClipboard' -Namespace Win32 -PassThru
# $api::OpenClipboard(hWndNewOwner)

#uselib "USER32.dll"
#func global OpenClipboard "OpenClipboard" sptr
; OpenClipboard hWndNewOwner   ; 戻り値は stat
; hWndNewOwner : HWND optional -> "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 OpenClipboard "OpenClipboard" sptr
; res = OpenClipboard(hWndNewOwner)
; hWndNewOwner : HWND optional -> "sptr"

; BOOL OpenClipboard(HWND hWndNewOwner)
#uselib "USER32.dll"
#cfunc global OpenClipboard "OpenClipboard" intptr
; res = OpenClipboard(hWndNewOwner)
; hWndNewOwner : HWND optional -> "intptr"

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

var (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procOpenClipboard = user32.NewProc("OpenClipboard")
)

// hWndNewOwner (HWND optional)
r1, _, err := procOpenClipboard.Call(
	uintptr(hWndNewOwner),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function OpenClipboard(
  hWndNewOwner: THandle   // HWND optional
): BOOL; stdcall;
  external 'USER32.dll' name 'OpenClipboard';

result := DllCall("USER32\OpenClipboard"
    , "Ptr", hWndNewOwner   ; HWND optional
    , "Int")   ; return: BOOL

●OpenClipboard(hWndNewOwner) = DLL("USER32.dll", "bool OpenClipboard(void*)")
# 呼び出し: OpenClipboard(hWndNewOwner)
# hWndNewOwner : HWND optional -> "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)。