OpenDesktopA

// USER32.dll  (ANSI / -A)
#include <windows.h>

HDESK OpenDesktopA(
    LPCSTR lpszDesktop,
    DESKTOP_CONTROL_FLAGS dwFlags,
    BOOL fInherit,
    DWORD dwDesiredAccess
);

<DllImport("USER32.dll", CharSet:=CharSet.Ansi, SetLastError:=True, ExactSpelling:=True)>
Public Shared Function OpenDesktopA(
    <MarshalAs(UnmanagedType.LPStr)> lpszDesktop As String,   ' LPCSTR
    dwFlags As UInteger,   ' DESKTOP_CONTROL_FLAGS
    fInherit As Boolean,   ' BOOL
    dwDesiredAccess As UInteger   ' DWORD
) As IntPtr
End Function

' lpszDesktop : LPCSTR
' dwFlags : DESKTOP_CONTROL_FLAGS
' fInherit : BOOL
' dwDesiredAccess : DWORD
Declare PtrSafe Function OpenDesktopA Lib "user32" ( _
    ByVal lpszDesktop As String, _
    ByVal dwFlags As Long, _
    ByVal fInherit As Long, _
    ByVal dwDesiredAccess 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

OpenDesktopA = ctypes.windll.user32.OpenDesktopA
OpenDesktopA.restype = ctypes.c_void_p
OpenDesktopA.argtypes = [
    wintypes.LPCSTR,  # lpszDesktop : LPCSTR
    wintypes.DWORD,  # dwFlags : DESKTOP_CONTROL_FLAGS
    wintypes.BOOL,  # fInherit : BOOL
    wintypes.DWORD,  # dwDesiredAccess : DWORD
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
OpenDesktopA = Fiddle::Function.new(
  lib['OpenDesktopA'],
  [
    Fiddle::TYPE_VOIDP,  # lpszDesktop : LPCSTR
    -Fiddle::TYPE_INT,  # dwFlags : DESKTOP_CONTROL_FLAGS
    Fiddle::TYPE_INT,  # fInherit : BOOL
    -Fiddle::TYPE_INT,  # dwDesiredAccess : DWORD
  ],
  Fiddle::TYPE_VOIDP)

#[link(name = "user32")]
extern "system" {
    fn OpenDesktopA(
        lpszDesktop: *const u8,  // LPCSTR
        dwFlags: u32,  // DESKTOP_CONTROL_FLAGS
        fInherit: i32,  // BOOL
        dwDesiredAccess: u32  // DWORD
    ) -> *mut core::ffi::c_void;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("USER32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
public static extern IntPtr OpenDesktopA([MarshalAs(UnmanagedType.LPStr)] string lpszDesktop, uint dwFlags, bool fInherit, uint dwDesiredAccess);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_OpenDesktopA' -Namespace Win32 -PassThru
# $api::OpenDesktopA(lpszDesktop, dwFlags, fInherit, dwDesiredAccess)

#uselib "USER32.dll"
#func global OpenDesktopA "OpenDesktopA" sptr, sptr, sptr, sptr
; OpenDesktopA lpszDesktop, dwFlags, fInherit, dwDesiredAccess   ; 戻り値は stat
; lpszDesktop : LPCSTR -> "sptr"
; dwFlags : DESKTOP_CONTROL_FLAGS -> "sptr"
; fInherit : BOOL -> "sptr"
; dwDesiredAccess : DWORD -> "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 OpenDesktopA "OpenDesktopA" str, int, int, int
; res = OpenDesktopA(lpszDesktop, dwFlags, fInherit, dwDesiredAccess)
; lpszDesktop : LPCSTR -> "str"
; dwFlags : DESKTOP_CONTROL_FLAGS -> "int"
; fInherit : BOOL -> "int"
; dwDesiredAccess : DWORD -> "int"

; HDESK OpenDesktopA(LPCSTR lpszDesktop, DESKTOP_CONTROL_FLAGS dwFlags, BOOL fInherit, DWORD dwDesiredAccess)
#uselib "USER32.dll"
#cfunc global OpenDesktopA "OpenDesktopA" str, int, int, int
; res = OpenDesktopA(lpszDesktop, dwFlags, fInherit, dwDesiredAccess)
; lpszDesktop : LPCSTR -> "str"
; dwFlags : DESKTOP_CONTROL_FLAGS -> "int"
; fInherit : BOOL -> "int"
; dwDesiredAccess : DWORD -> "int"

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

var (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procOpenDesktopA = user32.NewProc("OpenDesktopA")
)

// lpszDesktop (LPCSTR), dwFlags (DESKTOP_CONTROL_FLAGS), fInherit (BOOL), dwDesiredAccess (DWORD)
r1, _, err := procOpenDesktopA.Call(
	uintptr(unsafe.Pointer(windows.BytePtrFromString(lpszDesktop))),
	uintptr(dwFlags),
	uintptr(fInherit),
	uintptr(dwDesiredAccess),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HDESK

function OpenDesktopA(
  lpszDesktop: PAnsiChar;   // LPCSTR
  dwFlags: DWORD;   // DESKTOP_CONTROL_FLAGS
  fInherit: BOOL;   // BOOL
  dwDesiredAccess: DWORD   // DWORD
): THandle; stdcall;
  external 'USER32.dll' name 'OpenDesktopA';

result := DllCall("USER32\OpenDesktopA"
    , "AStr", lpszDesktop   ; LPCSTR
    , "UInt", dwFlags   ; DESKTOP_CONTROL_FLAGS
    , "Int", fInherit   ; BOOL
    , "UInt", dwDesiredAccess   ; DWORD
    , "Ptr")   ; return: HDESK

●OpenDesktopA(lpszDesktop, dwFlags, fInherit, dwDesiredAccess) = DLL("USER32.dll", "void* OpenDesktopA(char*, dword, bool, dword)")
# 呼び出し: OpenDesktopA(lpszDesktop, dwFlags, fInherit, dwDesiredAccess)
# lpszDesktop : LPCSTR -> "char*"
# dwFlags : DESKTOP_CONTROL_FLAGS -> "dword"
# fInherit : BOOL -> "bool"
# dwDesiredAccess : DWORD -> "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)。