InternetOpenUrlW

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

void* InternetOpenUrlW(
    void* hInternet,
    LPCWSTR lpszUrl,
    LPCWSTR lpszHeaders,   // optional
    DWORD dwHeadersLength,
    DWORD dwFlags,
    UINT_PTR dwContext   // optional
);

<DllImport("WININET.dll", CharSet:=CharSet.Unicode, SetLastError:=True, ExactSpelling:=True)>
Public Shared Function InternetOpenUrlW(
    hInternet As IntPtr,   ' void*
    <MarshalAs(UnmanagedType.LPWStr)> lpszUrl As String,   ' LPCWSTR
    <MarshalAs(UnmanagedType.LPWStr)> lpszHeaders As String,   ' LPCWSTR optional
    dwHeadersLength As UInteger,   ' DWORD
    dwFlags As UInteger,   ' DWORD
    dwContext As UIntPtr   ' UINT_PTR optional
) As IntPtr
End Function

' hInternet : void*
' lpszUrl : LPCWSTR
' lpszHeaders : LPCWSTR optional
' dwHeadersLength : DWORD
' dwFlags : DWORD
' dwContext : UINT_PTR optional
Declare PtrSafe Function InternetOpenUrlW Lib "wininet" ( _
    ByVal hInternet As LongPtr, _
    ByVal lpszUrl As LongPtr, _
    ByVal lpszHeaders As LongPtr, _
    ByVal dwHeadersLength As Long, _
    ByVal dwFlags As Long, _
    ByVal dwContext As LongPtr) As LongPtr
' 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

InternetOpenUrlW = ctypes.windll.wininet.InternetOpenUrlW
InternetOpenUrlW.restype = ctypes.c_void_p
InternetOpenUrlW.argtypes = [
    ctypes.POINTER(None),  # hInternet : void*
    wintypes.LPCWSTR,  # lpszUrl : LPCWSTR
    wintypes.LPCWSTR,  # lpszHeaders : LPCWSTR optional
    wintypes.DWORD,  # dwHeadersLength : DWORD
    wintypes.DWORD,  # dwFlags : DWORD
    ctypes.c_size_t,  # dwContext : UINT_PTR optional
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

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

#[link(name = "wininet")]
extern "system" {
    fn InternetOpenUrlW(
        hInternet: *mut (),  // void*
        lpszUrl: *const u16,  // LPCWSTR
        lpszHeaders: *const u16,  // LPCWSTR optional
        dwHeadersLength: u32,  // DWORD
        dwFlags: u32,  // DWORD
        dwContext: usize  // UINT_PTR optional
    ) -> *mut ();
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("WININET.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern IntPtr InternetOpenUrlW(IntPtr hInternet, [MarshalAs(UnmanagedType.LPWStr)] string lpszUrl, [MarshalAs(UnmanagedType.LPWStr)] string lpszHeaders, uint dwHeadersLength, uint dwFlags, UIntPtr dwContext);
"@
$api = Add-Type -MemberDefinition $sig -Name 'WININET_InternetOpenUrlW' -Namespace Win32 -PassThru
# $api::InternetOpenUrlW(hInternet, lpszUrl, lpszHeaders, dwHeadersLength, dwFlags, dwContext)

#uselib "WININET.dll"
#func global InternetOpenUrlW "InternetOpenUrlW" wptr, wptr, wptr, wptr, wptr, wptr
; InternetOpenUrlW hInternet, lpszUrl, lpszHeaders, dwHeadersLength, dwFlags, dwContext   ; 戻り値は stat
; hInternet : void* -> "wptr"
; lpszUrl : LPCWSTR -> "wptr"
; lpszHeaders : LPCWSTR optional -> "wptr"
; dwHeadersLength : DWORD -> "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 InternetOpenUrlW "InternetOpenUrlW" sptr, wstr, wstr, int, int, sptr
; res = InternetOpenUrlW(hInternet, lpszUrl, lpszHeaders, dwHeadersLength, dwFlags, dwContext)
; hInternet : void* -> "sptr"
; lpszUrl : LPCWSTR -> "wstr"
; lpszHeaders : LPCWSTR optional -> "wstr"
; dwHeadersLength : DWORD -> "int"
; dwFlags : DWORD -> "int"
; dwContext : UINT_PTR optional -> "sptr"

; void* InternetOpenUrlW(void* hInternet, LPCWSTR lpszUrl, LPCWSTR lpszHeaders, DWORD dwHeadersLength, DWORD dwFlags, UINT_PTR dwContext)
#uselib "WININET.dll"
#cfunc global InternetOpenUrlW "InternetOpenUrlW" intptr, wstr, wstr, int, int, intptr
; res = InternetOpenUrlW(hInternet, lpszUrl, lpszHeaders, dwHeadersLength, dwFlags, dwContext)
; hInternet : void* -> "intptr"
; lpszUrl : LPCWSTR -> "wstr"
; lpszHeaders : LPCWSTR optional -> "wstr"
; dwHeadersLength : DWORD -> "int"
; dwFlags : DWORD -> "int"
; dwContext : UINT_PTR optional -> "intptr"

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

var (
	wininet = windows.NewLazySystemDLL("WININET.dll")
	procInternetOpenUrlW = wininet.NewProc("InternetOpenUrlW")
)

// hInternet (void*), lpszUrl (LPCWSTR), lpszHeaders (LPCWSTR optional), dwHeadersLength (DWORD), dwFlags (DWORD), dwContext (UINT_PTR optional)
r1, _, err := procInternetOpenUrlW.Call(
	uintptr(hInternet),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(lpszUrl))),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(lpszHeaders))),
	uintptr(dwHeadersLength),
	uintptr(dwFlags),
	uintptr(dwContext),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // void*

function InternetOpenUrlW(
  hInternet: Pointer;   // void*
  lpszUrl: PWideChar;   // LPCWSTR
  lpszHeaders: PWideChar;   // LPCWSTR optional
  dwHeadersLength: DWORD;   // DWORD
  dwFlags: DWORD;   // DWORD
  dwContext: NativeUInt   // UINT_PTR optional
): Pointer; stdcall;
  external 'WININET.dll' name 'InternetOpenUrlW';

result := DllCall("WININET\InternetOpenUrlW"
    , "Ptr", hInternet   ; void*
    , "WStr", lpszUrl   ; LPCWSTR
    , "WStr", lpszHeaders   ; LPCWSTR optional
    , "UInt", dwHeadersLength   ; DWORD
    , "UInt", dwFlags   ; DWORD
    , "UPtr", dwContext   ; UINT_PTR optional
    , "Ptr")   ; return: void*

●InternetOpenUrlW(hInternet, lpszUrl, lpszHeaders, dwHeadersLength, dwFlags, dwContext) = DLL("WININET.dll", "void* InternetOpenUrlW(void*, char*, char*, dword, dword, int)")
# 呼び出し: InternetOpenUrlW(hInternet, lpszUrl, lpszHeaders, dwHeadersLength, dwFlags, dwContext)
# hInternet : void* -> "void*"
# lpszUrl : LPCWSTR -> "char*"
# lpszHeaders : LPCWSTR optional -> "char*"
# dwHeadersLength : DWORD -> "dword"
# 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。