GetScrollInfo

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

BOOL GetScrollInfo(
    HWND hwnd,
    SCROLLBAR_CONSTANTS nBar,
    SCROLLINFO* lpsi
);

<DllImport("USER32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function GetScrollInfo(
    hwnd As IntPtr,   ' HWND
    nBar As Integer,   ' SCROLLBAR_CONSTANTS
    lpsi As IntPtr   ' SCROLLINFO* in/out
) As Boolean
End Function

' hwnd : HWND
' nBar : SCROLLBAR_CONSTANTS
' lpsi : SCROLLINFO* in/out
Declare PtrSafe Function GetScrollInfo Lib "user32" ( _
    ByVal hwnd As LongPtr, _
    ByVal nBar As Long, _
    ByVal lpsi 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

GetScrollInfo = ctypes.windll.user32.GetScrollInfo
GetScrollInfo.restype = wintypes.BOOL
GetScrollInfo.argtypes = [
    wintypes.HANDLE,  # hwnd : HWND
    ctypes.c_int,  # nBar : SCROLLBAR_CONSTANTS
    ctypes.c_void_p,  # lpsi : SCROLLINFO* in/out
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
GetScrollInfo = Fiddle::Function.new(
  lib['GetScrollInfo'],
  [
    Fiddle::TYPE_VOIDP,  # hwnd : HWND
    Fiddle::TYPE_INT,  # nBar : SCROLLBAR_CONSTANTS
    Fiddle::TYPE_VOIDP,  # lpsi : SCROLLINFO* in/out
  ],
  Fiddle::TYPE_INT)

#[link(name = "user32")]
extern "system" {
    fn GetScrollInfo(
        hwnd: *mut core::ffi::c_void,  // HWND
        nBar: i32,  // SCROLLBAR_CONSTANTS
        lpsi: *mut SCROLLINFO  // SCROLLINFO* in/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 GetScrollInfo(IntPtr hwnd, int nBar, IntPtr lpsi);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_GetScrollInfo' -Namespace Win32 -PassThru
# $api::GetScrollInfo(hwnd, nBar, lpsi)

#uselib "USER32.dll"
#func global GetScrollInfo "GetScrollInfo" sptr, sptr, sptr
; GetScrollInfo hwnd, nBar, varptr(lpsi)   ; 戻り値は stat
; hwnd : HWND -> "sptr"
; nBar : SCROLLBAR_CONSTANTS -> "sptr"
; lpsi : SCROLLINFO* in/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。

#uselib "USER32.dll"
#cfunc global GetScrollInfo "GetScrollInfo" sptr, int, var
; res = GetScrollInfo(hwnd, nBar, lpsi)
; hwnd : HWND -> "sptr"
; nBar : SCROLLBAR_CONSTANTS -> "int"
; lpsi : SCROLLINFO* in/out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

; BOOL GetScrollInfo(HWND hwnd, SCROLLBAR_CONSTANTS nBar, SCROLLINFO* lpsi)
#uselib "USER32.dll"
#cfunc global GetScrollInfo "GetScrollInfo" intptr, int, var
; res = GetScrollInfo(hwnd, nBar, lpsi)
; hwnd : HWND -> "intptr"
; nBar : SCROLLBAR_CONSTANTS -> "int"
; lpsi : SCROLLINFO* in/out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

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

var (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procGetScrollInfo = user32.NewProc("GetScrollInfo")
)

// hwnd (HWND), nBar (SCROLLBAR_CONSTANTS), lpsi (SCROLLINFO* in/out)
r1, _, err := procGetScrollInfo.Call(
	uintptr(hwnd),
	uintptr(nBar),
	uintptr(lpsi),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function GetScrollInfo(
  hwnd: THandle;   // HWND
  nBar: Integer;   // SCROLLBAR_CONSTANTS
  lpsi: Pointer   // SCROLLINFO* in/out
): BOOL; stdcall;
  external 'USER32.dll' name 'GetScrollInfo';

result := DllCall("USER32\GetScrollInfo"
    , "Ptr", hwnd   ; HWND
    , "Int", nBar   ; SCROLLBAR_CONSTANTS
    , "Ptr", lpsi   ; SCROLLINFO* in/out
    , "Int")   ; return: BOOL

●GetScrollInfo(hwnd, nBar, lpsi) = DLL("USER32.dll", "bool GetScrollInfo(void*, int, void*)")
# 呼び出し: GetScrollInfo(hwnd, nBar, lpsi)
# hwnd : HWND -> "void*"
# nBar : SCROLLBAR_CONSTANTS -> "int"
# lpsi : SCROLLINFO* in/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)。