VarFormatDateTime

// OLEAUT32.dll
#include <windows.h>

HRESULT VarFormatDateTime(
    VARIANT* pvarIn,
    VARFORMAT_NAMED_FORMAT iNamedFormat,
    DWORD dwFlags,
    LPWSTR* pbstrOut
);

<DllImport("OLEAUT32.dll", ExactSpelling:=True)>
Public Shared Function VarFormatDateTime(
    pvarIn As IntPtr,   ' VARIANT*
    iNamedFormat As Integer,   ' VARFORMAT_NAMED_FORMAT
    dwFlags As UInteger,   ' DWORD
    pbstrOut As IntPtr   ' LPWSTR* out
) As Integer
End Function

' pvarIn : VARIANT*
' iNamedFormat : VARFORMAT_NAMED_FORMAT
' dwFlags : DWORD
' pbstrOut : LPWSTR* out
Declare PtrSafe Function VarFormatDateTime Lib "oleaut32" ( _
    ByVal pvarIn As LongPtr, _
    ByVal iNamedFormat As Long, _
    ByVal dwFlags As Long, _
    ByVal pbstrOut 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

VarFormatDateTime = ctypes.windll.oleaut32.VarFormatDateTime
VarFormatDateTime.restype = ctypes.c_int
VarFormatDateTime.argtypes = [
    ctypes.c_void_p,  # pvarIn : VARIANT*
    ctypes.c_int,  # iNamedFormat : VARFORMAT_NAMED_FORMAT
    wintypes.DWORD,  # dwFlags : DWORD
    ctypes.c_void_p,  # pbstrOut : LPWSTR* out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('OLEAUT32.dll')
VarFormatDateTime = Fiddle::Function.new(
  lib['VarFormatDateTime'],
  [
    Fiddle::TYPE_VOIDP,  # pvarIn : VARIANT*
    Fiddle::TYPE_INT,  # iNamedFormat : VARFORMAT_NAMED_FORMAT
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
    Fiddle::TYPE_VOIDP,  # pbstrOut : LPWSTR* out
  ],
  Fiddle::TYPE_INT)

#[link(name = "oleaut32")]
extern "system" {
    fn VarFormatDateTime(
        pvarIn: *mut VARIANT,  // VARIANT*
        iNamedFormat: i32,  // VARFORMAT_NAMED_FORMAT
        dwFlags: u32,  // DWORD
        pbstrOut: *mut *mut u16  // LPWSTR* out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("OLEAUT32.dll")]
public static extern int VarFormatDateTime(IntPtr pvarIn, int iNamedFormat, uint dwFlags, IntPtr pbstrOut);
"@
$api = Add-Type -MemberDefinition $sig -Name 'OLEAUT32_VarFormatDateTime' -Namespace Win32 -PassThru
# $api::VarFormatDateTime(pvarIn, iNamedFormat, dwFlags, pbstrOut)

#uselib "OLEAUT32.dll"
#func global VarFormatDateTime "VarFormatDateTime" sptr, sptr, sptr, sptr
; VarFormatDateTime varptr(pvarIn), iNamedFormat, dwFlags, varptr(pbstrOut)   ; 戻り値は stat
; pvarIn : VARIANT* -> "sptr"
; iNamedFormat : VARFORMAT_NAMED_FORMAT -> "sptr"
; dwFlags : DWORD -> "sptr"
; pbstrOut : LPWSTR* 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 "OLEAUT32.dll"
#cfunc global VarFormatDateTime "VarFormatDateTime" var, int, int, var
; res = VarFormatDateTime(pvarIn, iNamedFormat, dwFlags, pbstrOut)
; pvarIn : VARIANT* -> "var"
; iNamedFormat : VARFORMAT_NAMED_FORMAT -> "int"
; dwFlags : DWORD -> "int"
; pbstrOut : LPWSTR* 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。

; HRESULT VarFormatDateTime(VARIANT* pvarIn, VARFORMAT_NAMED_FORMAT iNamedFormat, DWORD dwFlags, LPWSTR* pbstrOut)
#uselib "OLEAUT32.dll"
#cfunc global VarFormatDateTime "VarFormatDateTime" var, int, int, var
; res = VarFormatDateTime(pvarIn, iNamedFormat, dwFlags, pbstrOut)
; pvarIn : VARIANT* -> "var"
; iNamedFormat : VARFORMAT_NAMED_FORMAT -> "int"
; dwFlags : DWORD -> "int"
; pbstrOut : LPWSTR* 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 (
	oleaut32 = windows.NewLazySystemDLL("OLEAUT32.dll")
	procVarFormatDateTime = oleaut32.NewProc("VarFormatDateTime")
)

// pvarIn (VARIANT*), iNamedFormat (VARFORMAT_NAMED_FORMAT), dwFlags (DWORD), pbstrOut (LPWSTR* out)
r1, _, err := procVarFormatDateTime.Call(
	uintptr(pvarIn),
	uintptr(iNamedFormat),
	uintptr(dwFlags),
	uintptr(pbstrOut),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function VarFormatDateTime(
  pvarIn: Pointer;   // VARIANT*
  iNamedFormat: Integer;   // VARFORMAT_NAMED_FORMAT
  dwFlags: DWORD;   // DWORD
  pbstrOut: PPWideChar   // LPWSTR* out
): Integer; stdcall;
  external 'OLEAUT32.dll' name 'VarFormatDateTime';

result := DllCall("OLEAUT32\VarFormatDateTime"
    , "Ptr", pvarIn   ; VARIANT*
    , "Int", iNamedFormat   ; VARFORMAT_NAMED_FORMAT
    , "UInt", dwFlags   ; DWORD
    , "Ptr", pbstrOut   ; LPWSTR* out
    , "Int")   ; return: HRESULT

●VarFormatDateTime(pvarIn, iNamedFormat, dwFlags, pbstrOut) = DLL("OLEAUT32.dll", "int VarFormatDateTime(void*, int, dword, void*)")
# 呼び出し: VarFormatDateTime(pvarIn, iNamedFormat, dwFlags, pbstrOut)
# pvarIn : VARIANT* -> "void*"
# iNamedFormat : VARFORMAT_NAMED_FORMAT -> "int"
# dwFlags : DWORD -> "dword"
# pbstrOut : LPWSTR* 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)。