GetFocus

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

HWND GetFocus(void);

<DllImport("USER32.dll", ExactSpelling:=True)>
Public Shared Function GetFocus() As IntPtr
End Function

Declare PtrSafe Function GetFocus Lib "user32" () As LongPtr
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

GetFocus = ctypes.windll.user32.GetFocus
GetFocus.restype = ctypes.c_void_p
GetFocus.argtypes = []

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
GetFocus = Fiddle::Function.new(
  lib['GetFocus'],
  [],
  Fiddle::TYPE_VOIDP)

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

$sig = @"
[DllImport("USER32.dll")]
public static extern IntPtr GetFocus();
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_GetFocus' -Namespace Win32 -PassThru
# $api::GetFocus()

#uselib "USER32.dll"
#func global GetFocus "GetFocus"
; GetFocus   ; 戻り値は stat
; ※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 GetFocus "GetFocus"
; res = GetFocus()

; HWND GetFocus()
#uselib "USER32.dll"
#cfunc global GetFocus "GetFocus"
; res = GetFocus()

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

var (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procGetFocus = user32.NewProc("GetFocus")
)

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

function GetFocus: THandle; stdcall;
  external 'USER32.dll' name 'GetFocus';

result := DllCall("USER32\GetFocus", "Ptr")

●GetFocus() = DLL("USER32.dll", "void* GetFocus()")
# 呼び出し: GetFocus()
# 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)。