URLDownloadToFileW

// urlmon.dll  (Unicode / -W)
#include <windows.h>

HRESULT URLDownloadToFileW(
    IUnknown* param0,   // optional
    LPCWSTR param1,
    LPCWSTR param2,   // optional
    DWORD param3,
    IBindStatusCallback* param4   // optional
);

<DllImport("urlmon.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function URLDownloadToFileW(
    param0 As IntPtr,   ' IUnknown* optional
    <MarshalAs(UnmanagedType.LPWStr)> param1 As String,   ' LPCWSTR
    <MarshalAs(UnmanagedType.LPWStr)> param2 As String,   ' LPCWSTR optional
    param3 As UInteger,   ' DWORD
    param4 As IntPtr   ' IBindStatusCallback* optional
) As Integer
End Function

' param0 : IUnknown* optional
' param1 : LPCWSTR
' param2 : LPCWSTR optional
' param3 : DWORD
' param4 : IBindStatusCallback* optional
Declare PtrSafe Function URLDownloadToFileW Lib "urlmon" ( _
    ByVal param0 As LongPtr, _
    ByVal param1 As LongPtr, _
    ByVal param2 As LongPtr, _
    ByVal param3 As Long, _
    ByVal param4 As LongPtr) As Long
' Unicode(W): 文字列は ByVal As LongPtr とし StrPtr(unicodeStr) を渡す
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

URLDownloadToFileW = ctypes.windll.urlmon.URLDownloadToFileW
URLDownloadToFileW.restype = ctypes.c_int
URLDownloadToFileW.argtypes = [
    ctypes.c_void_p,  # param0 : IUnknown* optional
    wintypes.LPCWSTR,  # param1 : LPCWSTR
    wintypes.LPCWSTR,  # param2 : LPCWSTR optional
    wintypes.DWORD,  # param3 : DWORD
    ctypes.c_void_p,  # param4 : IBindStatusCallback* optional
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('urlmon.dll')
URLDownloadToFileW = Fiddle::Function.new(
  lib['URLDownloadToFileW'],
  [
    Fiddle::TYPE_VOIDP,  # param0 : IUnknown* optional
    Fiddle::TYPE_VOIDP,  # param1 : LPCWSTR
    Fiddle::TYPE_VOIDP,  # param2 : LPCWSTR optional
    -Fiddle::TYPE_INT,  # param3 : DWORD
    Fiddle::TYPE_VOIDP,  # param4 : IBindStatusCallback* optional
  ],
  Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "urlmon")]
extern "system" {
    fn URLDownloadToFileW(
        param0: *mut core::ffi::c_void,  // IUnknown* optional
        param1: *const u16,  // LPCWSTR
        param2: *const u16,  // LPCWSTR optional
        param3: u32,  // DWORD
        param4: *mut core::ffi::c_void  // IBindStatusCallback* optional
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("urlmon.dll", CharSet = CharSet.Unicode)]
public static extern int URLDownloadToFileW(IntPtr param0, [MarshalAs(UnmanagedType.LPWStr)] string param1, [MarshalAs(UnmanagedType.LPWStr)] string param2, uint param3, IntPtr param4);
"@
$api = Add-Type -MemberDefinition $sig -Name 'urlmon_URLDownloadToFileW' -Namespace Win32 -PassThru
# $api::URLDownloadToFileW(param0, param1, param2, param3, param4)

#uselib "urlmon.dll"
#func global URLDownloadToFileW "URLDownloadToFileW" wptr, wptr, wptr, wptr, wptr
; URLDownloadToFileW param0, param1, param2, param3, param4   ; 戻り値は stat
; param0 : IUnknown* optional -> "wptr"
; param1 : LPCWSTR -> "wptr"
; param2 : LPCWSTR optional -> "wptr"
; param3 : DWORD -> "wptr"
; param4 : IBindStatusCallback* optional -> "wptr"
; ※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 "urlmon.dll"
#cfunc global URLDownloadToFileW "URLDownloadToFileW" sptr, wstr, wstr, int, sptr
; res = URLDownloadToFileW(param0, param1, param2, param3, param4)
; param0 : IUnknown* optional -> "sptr"
; param1 : LPCWSTR -> "wstr"
; param2 : LPCWSTR optional -> "wstr"
; param3 : DWORD -> "int"
; param4 : IBindStatusCallback* optional -> "sptr"

; HRESULT URLDownloadToFileW(IUnknown* param0, LPCWSTR param1, LPCWSTR param2, DWORD param3, IBindStatusCallback* param4)
#uselib "urlmon.dll"
#cfunc global URLDownloadToFileW "URLDownloadToFileW" intptr, wstr, wstr, int, intptr
; res = URLDownloadToFileW(param0, param1, param2, param3, param4)
; param0 : IUnknown* optional -> "intptr"
; param1 : LPCWSTR -> "wstr"
; param2 : LPCWSTR optional -> "wstr"
; param3 : DWORD -> "int"
; param4 : IBindStatusCallback* optional -> "intptr"

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

var (
	urlmon = windows.NewLazySystemDLL("urlmon.dll")
	procURLDownloadToFileW = urlmon.NewProc("URLDownloadToFileW")
)

// param0 (IUnknown* optional), param1 (LPCWSTR), param2 (LPCWSTR optional), param3 (DWORD), param4 (IBindStatusCallback* optional)
r1, _, err := procURLDownloadToFileW.Call(
	uintptr(param0),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(param1))),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(param2))),
	uintptr(param3),
	uintptr(param4),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function URLDownloadToFileW(
  param0: Pointer;   // IUnknown* optional
  param1: PWideChar;   // LPCWSTR
  param2: PWideChar;   // LPCWSTR optional
  param3: DWORD;   // DWORD
  param4: Pointer   // IBindStatusCallback* optional
): Integer; stdcall;
  external 'urlmon.dll' name 'URLDownloadToFileW';

result := DllCall("urlmon\URLDownloadToFileW"
    , "Ptr", param0   ; IUnknown* optional
    , "WStr", param1   ; LPCWSTR
    , "WStr", param2   ; LPCWSTR optional
    , "UInt", param3   ; DWORD
    , "Ptr", param4   ; IBindStatusCallback* optional
    , "Int")   ; return: HRESULT

●URLDownloadToFileW(param0, param1, param2, param3, param4) = DLL("urlmon.dll", "int URLDownloadToFileW(void*, char*, char*, dword, void*)")
# 呼び出し: URLDownloadToFileW(param0, param1, param2, param3, param4)
# param0 : IUnknown* optional -> "void*"
# param1 : LPCWSTR -> "char*"
# param2 : LPCWSTR optional -> "char*"
# param3 : DWORD -> "dword"
# param4 : IBindStatusCallback* optional -> "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)。
# ※-W(Unicode)関数。なでしこ1はANSIのため -A 版の利用を推奨。