InternetWriteFileExW

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

BOOL InternetWriteFileExW(
    void* hFile,
    INTERNET_BUFFERSW* lpBuffersIn,
    DWORD dwFlags,
    UINT_PTR dwContext   // optional
);

<DllImport("WININET.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function InternetWriteFileExW(
    hFile As IntPtr,   ' void*
    lpBuffersIn As IntPtr,   ' INTERNET_BUFFERSW*
    dwFlags As UInteger,   ' DWORD
    dwContext As UIntPtr   ' UINT_PTR optional
) As Boolean
End Function

' hFile : void*
' lpBuffersIn : INTERNET_BUFFERSW*
' dwFlags : DWORD
' dwContext : UINT_PTR optional
Declare PtrSafe Function InternetWriteFileExW Lib "wininet" ( _
    ByVal hFile As LongPtr, _
    ByVal lpBuffersIn As LongPtr, _
    ByVal dwFlags As Long, _
    ByVal dwContext 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

InternetWriteFileExW = ctypes.windll.wininet.InternetWriteFileExW
InternetWriteFileExW.restype = wintypes.BOOL
InternetWriteFileExW.argtypes = [
    ctypes.POINTER(None),  # hFile : void*
    ctypes.c_void_p,  # lpBuffersIn : INTERNET_BUFFERSW*
    wintypes.DWORD,  # dwFlags : DWORD
    ctypes.c_size_t,  # dwContext : UINT_PTR optional
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('WININET.dll')
InternetWriteFileExW = Fiddle::Function.new(
  lib['InternetWriteFileExW'],
  [
    Fiddle::TYPE_VOIDP,  # hFile : void*
    Fiddle::TYPE_VOIDP,  # lpBuffersIn : INTERNET_BUFFERSW*
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
    Fiddle::TYPE_UINTPTR_T,  # dwContext : UINT_PTR optional
  ],
  Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "wininet")]
extern "system" {
    fn InternetWriteFileExW(
        hFile: *mut (),  // void*
        lpBuffersIn: *mut INTERNET_BUFFERSW,  // INTERNET_BUFFERSW*
        dwFlags: u32,  // DWORD
        dwContext: usize  // UINT_PTR optional
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("WININET.dll", CharSet = CharSet.Unicode)]
public static extern bool InternetWriteFileExW(IntPtr hFile, IntPtr lpBuffersIn, uint dwFlags, UIntPtr dwContext);
"@
$api = Add-Type -MemberDefinition $sig -Name 'WININET_InternetWriteFileExW' -Namespace Win32 -PassThru
# $api::InternetWriteFileExW(hFile, lpBuffersIn, dwFlags, dwContext)

#uselib "WININET.dll"
#func global InternetWriteFileExW "InternetWriteFileExW" wptr, wptr, wptr, wptr
; InternetWriteFileExW hFile, varptr(lpBuffersIn), dwFlags, dwContext   ; 戻り値は stat
; hFile : void* -> "wptr"
; lpBuffersIn : INTERNET_BUFFERSW* -> "wptr"
; dwFlags : DWORD -> "wptr"
; dwContext : UINT_PTR 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 "WININET.dll"
#cfunc global InternetWriteFileExW "InternetWriteFileExW" sptr, var, int, sptr
; res = InternetWriteFileExW(hFile, lpBuffersIn, dwFlags, dwContext)
; hFile : void* -> "sptr"
; lpBuffersIn : INTERNET_BUFFERSW* -> "var"
; dwFlags : DWORD -> "int"
; dwContext : UINT_PTR optional -> "sptr"
; ※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 InternetWriteFileExW(void* hFile, INTERNET_BUFFERSW* lpBuffersIn, DWORD dwFlags, UINT_PTR dwContext)
#uselib "WININET.dll"
#cfunc global InternetWriteFileExW "InternetWriteFileExW" intptr, var, int, intptr
; res = InternetWriteFileExW(hFile, lpBuffersIn, dwFlags, dwContext)
; hFile : void* -> "intptr"
; lpBuffersIn : INTERNET_BUFFERSW* -> "var"
; dwFlags : DWORD -> "int"
; dwContext : UINT_PTR optional -> "intptr"
; ※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 (
	wininet = windows.NewLazySystemDLL("WININET.dll")
	procInternetWriteFileExW = wininet.NewProc("InternetWriteFileExW")
)

// hFile (void*), lpBuffersIn (INTERNET_BUFFERSW*), dwFlags (DWORD), dwContext (UINT_PTR optional)
r1, _, err := procInternetWriteFileExW.Call(
	uintptr(hFile),
	uintptr(lpBuffersIn),
	uintptr(dwFlags),
	uintptr(dwContext),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function InternetWriteFileExW(
  hFile: Pointer;   // void*
  lpBuffersIn: Pointer;   // INTERNET_BUFFERSW*
  dwFlags: DWORD;   // DWORD
  dwContext: NativeUInt   // UINT_PTR optional
): BOOL; stdcall;
  external 'WININET.dll' name 'InternetWriteFileExW';

result := DllCall("WININET\InternetWriteFileExW"
    , "Ptr", hFile   ; void*
    , "Ptr", lpBuffersIn   ; INTERNET_BUFFERSW*
    , "UInt", dwFlags   ; DWORD
    , "UPtr", dwContext   ; UINT_PTR optional
    , "Int")   ; return: BOOL

●InternetWriteFileExW(hFile, lpBuffersIn, dwFlags, dwContext) = DLL("WININET.dll", "bool InternetWriteFileExW(void*, void*, dword, int)")
# 呼び出し: InternetWriteFileExW(hFile, lpBuffersIn, dwFlags, dwContext)
# hFile : void* -> "void*"
# lpBuffersIn : INTERNET_BUFFERSW* -> "void*"
# dwFlags : DWORD -> "dword"
# dwContext : UINT_PTR optional -> "int"
# 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。