SHSetKnownFolderPath

// SHELL32.dll
#include <windows.h>

HRESULT SHSetKnownFolderPath(
    const GUID* rfid,
    DWORD dwFlags,
    HANDLE hToken,   // optional
    LPCWSTR pszPath
);

<DllImport("SHELL32.dll", ExactSpelling:=True)>
Public Shared Function SHSetKnownFolderPath(
    ByRef rfid As Guid,   ' GUID*
    dwFlags As UInteger,   ' DWORD
    hToken As IntPtr,   ' HANDLE optional
    <MarshalAs(UnmanagedType.LPWStr)> pszPath As String   ' LPCWSTR
) As Integer
End Function

' rfid : GUID*
' dwFlags : DWORD
' hToken : HANDLE optional
' pszPath : LPCWSTR
Declare PtrSafe Function SHSetKnownFolderPath Lib "shell32" ( _
    ByVal rfid As LongPtr, _
    ByVal dwFlags As Long, _
    ByVal hToken As LongPtr, _
    ByVal pszPath 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

SHSetKnownFolderPath = ctypes.windll.shell32.SHSetKnownFolderPath
SHSetKnownFolderPath.restype = ctypes.c_int
SHSetKnownFolderPath.argtypes = [
    ctypes.c_void_p,  # rfid : GUID*
    wintypes.DWORD,  # dwFlags : DWORD
    wintypes.HANDLE,  # hToken : HANDLE optional
    wintypes.LPCWSTR,  # pszPath : LPCWSTR
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('SHELL32.dll')
SHSetKnownFolderPath = Fiddle::Function.new(
  lib['SHSetKnownFolderPath'],
  [
    Fiddle::TYPE_VOIDP,  # rfid : GUID*
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
    Fiddle::TYPE_VOIDP,  # hToken : HANDLE optional
    Fiddle::TYPE_VOIDP,  # pszPath : LPCWSTR
  ],
  Fiddle::TYPE_INT)

#[link(name = "shell32")]
extern "system" {
    fn SHSetKnownFolderPath(
        rfid: *const GUID,  // GUID*
        dwFlags: u32,  // DWORD
        hToken: *mut core::ffi::c_void,  // HANDLE optional
        pszPath: *const u16  // LPCWSTR
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("SHELL32.dll")]
public static extern int SHSetKnownFolderPath(ref Guid rfid, uint dwFlags, IntPtr hToken, [MarshalAs(UnmanagedType.LPWStr)] string pszPath);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SHELL32_SHSetKnownFolderPath' -Namespace Win32 -PassThru
# $api::SHSetKnownFolderPath(rfid, dwFlags, hToken, pszPath)

#uselib "SHELL32.dll"
#func global SHSetKnownFolderPath "SHSetKnownFolderPath" sptr, sptr, sptr, sptr
; SHSetKnownFolderPath varptr(rfid), dwFlags, hToken, pszPath   ; 戻り値は stat
; rfid : GUID* -> "sptr"
; dwFlags : DWORD -> "sptr"
; hToken : HANDLE optional -> "sptr"
; pszPath : LPCWSTR -> "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 "SHELL32.dll"
#cfunc global SHSetKnownFolderPath "SHSetKnownFolderPath" var, int, sptr, wstr
; res = SHSetKnownFolderPath(rfid, dwFlags, hToken, pszPath)
; rfid : GUID* -> "var"
; dwFlags : DWORD -> "int"
; hToken : HANDLE optional -> "sptr"
; pszPath : LPCWSTR -> "wstr"
; ※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 SHSetKnownFolderPath(GUID* rfid, DWORD dwFlags, HANDLE hToken, LPCWSTR pszPath)
#uselib "SHELL32.dll"
#cfunc global SHSetKnownFolderPath "SHSetKnownFolderPath" var, int, intptr, wstr
; res = SHSetKnownFolderPath(rfid, dwFlags, hToken, pszPath)
; rfid : GUID* -> "var"
; dwFlags : DWORD -> "int"
; hToken : HANDLE optional -> "intptr"
; pszPath : LPCWSTR -> "wstr"
; ※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 (
	shell32 = windows.NewLazySystemDLL("SHELL32.dll")
	procSHSetKnownFolderPath = shell32.NewProc("SHSetKnownFolderPath")
)

// rfid (GUID*), dwFlags (DWORD), hToken (HANDLE optional), pszPath (LPCWSTR)
r1, _, err := procSHSetKnownFolderPath.Call(
	uintptr(rfid),
	uintptr(dwFlags),
	uintptr(hToken),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(pszPath))),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function SHSetKnownFolderPath(
  rfid: PGUID;   // GUID*
  dwFlags: DWORD;   // DWORD
  hToken: THandle;   // HANDLE optional
  pszPath: PWideChar   // LPCWSTR
): Integer; stdcall;
  external 'SHELL32.dll' name 'SHSetKnownFolderPath';

result := DllCall("SHELL32\SHSetKnownFolderPath"
    , "Ptr", rfid   ; GUID*
    , "UInt", dwFlags   ; DWORD
    , "Ptr", hToken   ; HANDLE optional
    , "WStr", pszPath   ; LPCWSTR
    , "Int")   ; return: HRESULT

●SHSetKnownFolderPath(rfid, dwFlags, hToken, pszPath) = DLL("SHELL32.dll", "int SHSetKnownFolderPath(void*, dword, void*, char*)")
# 呼び出し: SHSetKnownFolderPath(rfid, dwFlags, hToken, pszPath)
# rfid : GUID* -> "void*"
# dwFlags : DWORD -> "dword"
# hToken : HANDLE optional -> "void*"
# pszPath : LPCWSTR -> "char*"
# 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)。