SetProcessPreferredUILanguages

// KERNEL32.dll
#include <windows.h>

BOOL SetProcessPreferredUILanguages(
    DWORD dwFlags,
    LPCWSTR pwszLanguagesBuffer,   // optional
    DWORD* pulNumLanguages   // optional
);

<DllImport("KERNEL32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function SetProcessPreferredUILanguages(
    dwFlags As UInteger,   ' DWORD
    <MarshalAs(UnmanagedType.LPWStr)> pwszLanguagesBuffer As String,   ' LPCWSTR optional
    pulNumLanguages As IntPtr   ' DWORD* optional, out
) As Boolean
End Function

' dwFlags : DWORD
' pwszLanguagesBuffer : LPCWSTR optional
' pulNumLanguages : DWORD* optional, out
Declare PtrSafe Function SetProcessPreferredUILanguages Lib "kernel32" ( _
    ByVal dwFlags As Long, _
    ByVal pwszLanguagesBuffer As LongPtr, _
    ByVal pulNumLanguages 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

SetProcessPreferredUILanguages = ctypes.windll.kernel32.SetProcessPreferredUILanguages
SetProcessPreferredUILanguages.restype = wintypes.BOOL
SetProcessPreferredUILanguages.argtypes = [
    wintypes.DWORD,  # dwFlags : DWORD
    wintypes.LPCWSTR,  # pwszLanguagesBuffer : LPCWSTR optional
    ctypes.POINTER(wintypes.DWORD),  # pulNumLanguages : DWORD* optional, out
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('KERNEL32.dll')
SetProcessPreferredUILanguages = Fiddle::Function.new(
  lib['SetProcessPreferredUILanguages'],
  [
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
    Fiddle::TYPE_VOIDP,  # pwszLanguagesBuffer : LPCWSTR optional
    Fiddle::TYPE_VOIDP,  # pulNumLanguages : DWORD* optional, out
  ],
  Fiddle::TYPE_INT)

#[link(name = "kernel32")]
extern "system" {
    fn SetProcessPreferredUILanguages(
        dwFlags: u32,  // DWORD
        pwszLanguagesBuffer: *const u16,  // LPCWSTR optional
        pulNumLanguages: *mut u32  // DWORD* optional, out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("KERNEL32.dll", SetLastError = true)]
public static extern bool SetProcessPreferredUILanguages(uint dwFlags, [MarshalAs(UnmanagedType.LPWStr)] string pwszLanguagesBuffer, IntPtr pulNumLanguages);
"@
$api = Add-Type -MemberDefinition $sig -Name 'KERNEL32_SetProcessPreferredUILanguages' -Namespace Win32 -PassThru
# $api::SetProcessPreferredUILanguages(dwFlags, pwszLanguagesBuffer, pulNumLanguages)

#uselib "KERNEL32.dll"
#func global SetProcessPreferredUILanguages "SetProcessPreferredUILanguages" sptr, sptr, sptr
; SetProcessPreferredUILanguages dwFlags, pwszLanguagesBuffer, varptr(pulNumLanguages)   ; 戻り値は stat
; dwFlags : DWORD -> "sptr"
; pwszLanguagesBuffer : LPCWSTR optional -> "sptr"
; pulNumLanguages : DWORD* optional, 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 "KERNEL32.dll"
#cfunc global SetProcessPreferredUILanguages "SetProcessPreferredUILanguages" int, wstr, var
; res = SetProcessPreferredUILanguages(dwFlags, pwszLanguagesBuffer, pulNumLanguages)
; dwFlags : DWORD -> "int"
; pwszLanguagesBuffer : LPCWSTR optional -> "wstr"
; pulNumLanguages : DWORD* optional, 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 SetProcessPreferredUILanguages(DWORD dwFlags, LPCWSTR pwszLanguagesBuffer, DWORD* pulNumLanguages)
#uselib "KERNEL32.dll"
#cfunc global SetProcessPreferredUILanguages "SetProcessPreferredUILanguages" int, wstr, var
; res = SetProcessPreferredUILanguages(dwFlags, pwszLanguagesBuffer, pulNumLanguages)
; dwFlags : DWORD -> "int"
; pwszLanguagesBuffer : LPCWSTR optional -> "wstr"
; pulNumLanguages : DWORD* optional, 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 (
	kernel32 = windows.NewLazySystemDLL("KERNEL32.dll")
	procSetProcessPreferredUILanguages = kernel32.NewProc("SetProcessPreferredUILanguages")
)

// dwFlags (DWORD), pwszLanguagesBuffer (LPCWSTR optional), pulNumLanguages (DWORD* optional, out)
r1, _, err := procSetProcessPreferredUILanguages.Call(
	uintptr(dwFlags),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(pwszLanguagesBuffer))),
	uintptr(pulNumLanguages),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function SetProcessPreferredUILanguages(
  dwFlags: DWORD;   // DWORD
  pwszLanguagesBuffer: PWideChar;   // LPCWSTR optional
  pulNumLanguages: Pointer   // DWORD* optional, out
): BOOL; stdcall;
  external 'KERNEL32.dll' name 'SetProcessPreferredUILanguages';

result := DllCall("KERNEL32\SetProcessPreferredUILanguages"
    , "UInt", dwFlags   ; DWORD
    , "WStr", pwszLanguagesBuffer   ; LPCWSTR optional
    , "Ptr", pulNumLanguages   ; DWORD* optional, out
    , "Int")   ; return: BOOL

●SetProcessPreferredUILanguages(dwFlags, pwszLanguagesBuffer, pulNumLanguages) = DLL("KERNEL32.dll", "bool SetProcessPreferredUILanguages(dword, char*, void*)")
# 呼び出し: SetProcessPreferredUILanguages(dwFlags, pwszLanguagesBuffer, pulNumLanguages)
# dwFlags : DWORD -> "dword"
# pwszLanguagesBuffer : LPCWSTR optional -> "char*"
# pulNumLanguages : DWORD* optional, 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)。