WindowFromPoint

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

HWND WindowFromPoint(
    POINT Point
);

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

' Point : POINT
Declare PtrSafe Function WindowFromPoint Lib "user32" ( _
    ByVal Point As LongPtr) As LongPtr
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

WindowFromPoint = ctypes.windll.user32.WindowFromPoint
WindowFromPoint.restype = ctypes.c_void_p
WindowFromPoint.argtypes = [
    POINT,  # Point : POINT
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
WindowFromPoint = Fiddle::Function.new(
  lib['WindowFromPoint'],
  [
    Fiddle::TYPE_VOIDP,  # Point : POINT
  ],
  Fiddle::TYPE_VOIDP)

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

$sig = @"
[DllImport("USER32.dll")]
public static extern IntPtr WindowFromPoint(POINT Point);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_WindowFromPoint' -Namespace Win32 -PassThru
# $api::WindowFromPoint(Point)

#uselib "USER32.dll"
#func global WindowFromPoint "WindowFromPoint" sptr
; WindowFromPoint Point   ; 戻り値は stat
; Point : POINT -> "sptr"
; ※値渡し構造体は直接渡せません。intにパック、または var で構造体変数を渡してください。
; ※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 WindowFromPoint "WindowFromPoint" int
; res = WindowFromPoint(Point)
; Point : POINT -> "int"
; ※値渡し構造体は直接渡せません。intにパック、または var で構造体変数を渡してください。

; HWND WindowFromPoint(POINT Point)
#uselib "USER32.dll"
#cfunc global WindowFromPoint "WindowFromPoint" int
; res = WindowFromPoint(Point)
; Point : POINT -> "int"
; ※値渡し構造体は直接渡せません。intにパック、または var で構造体変数を渡してください。

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

var (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procWindowFromPoint = user32.NewProc("WindowFromPoint")
)

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

function WindowFromPoint(
  Point: POINT   // POINT
): THandle; stdcall;
  external 'USER32.dll' name 'WindowFromPoint';

result := DllCall("USER32\WindowFromPoint"
    , "Ptr", Point   ; POINT
    , "Ptr")   ; return: HWND

●WindowFromPoint(Point) = DLL("USER32.dll", "void* WindowFromPoint(void*)")
# 呼び出し: WindowFromPoint(Point)
# Point : POINT -> "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)。