WTSSendMessageW

// WTSAPI32.dll  (Unicode / -W)
#include <windows.h>

BOOL WTSSendMessageW(
    HANDLE hServer,   // optional
    DWORD SessionId,
    LPWSTR pTitle,
    DWORD TitleLength,
    LPWSTR pMessage,
    DWORD MessageLength,
    MESSAGEBOX_STYLE Style,
    DWORD Timeout,
    MESSAGEBOX_RESULT* pResponse,
    BOOL bWait
);

<DllImport("WTSAPI32.dll", CharSet:=CharSet.Unicode, SetLastError:=True, ExactSpelling:=True)>
Public Shared Function WTSSendMessageW(
    hServer As IntPtr,   ' HANDLE optional
    SessionId As UInteger,   ' DWORD
    <MarshalAs(UnmanagedType.LPWStr)> pTitle As String,   ' LPWSTR
    TitleLength As UInteger,   ' DWORD
    <MarshalAs(UnmanagedType.LPWStr)> pMessage As String,   ' LPWSTR
    MessageLength As UInteger,   ' DWORD
    Style As UInteger,   ' MESSAGEBOX_STYLE
    Timeout As UInteger,   ' DWORD
    <Out> ByRef pResponse As Integer,   ' MESSAGEBOX_RESULT* out
    bWait As Boolean   ' BOOL
) As Boolean
End Function

' hServer : HANDLE optional
' SessionId : DWORD
' pTitle : LPWSTR
' TitleLength : DWORD
' pMessage : LPWSTR
' MessageLength : DWORD
' Style : MESSAGEBOX_STYLE
' Timeout : DWORD
' pResponse : MESSAGEBOX_RESULT* out
' bWait : BOOL
Declare PtrSafe Function WTSSendMessageW Lib "wtsapi32" ( _
    ByVal hServer As LongPtr, _
    ByVal SessionId As Long, _
    ByVal pTitle As LongPtr, _
    ByVal TitleLength As Long, _
    ByVal pMessage As LongPtr, _
    ByVal MessageLength As Long, _
    ByVal Style As Long, _
    ByVal Timeout As Long, _
    ByRef pResponse As Long, _
    ByVal bWait As Long) 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

WTSSendMessageW = ctypes.windll.wtsapi32.WTSSendMessageW
WTSSendMessageW.restype = wintypes.BOOL
WTSSendMessageW.argtypes = [
    wintypes.HANDLE,  # hServer : HANDLE optional
    wintypes.DWORD,  # SessionId : DWORD
    wintypes.LPCWSTR,  # pTitle : LPWSTR
    wintypes.DWORD,  # TitleLength : DWORD
    wintypes.LPCWSTR,  # pMessage : LPWSTR
    wintypes.DWORD,  # MessageLength : DWORD
    wintypes.DWORD,  # Style : MESSAGEBOX_STYLE
    wintypes.DWORD,  # Timeout : DWORD
    ctypes.c_void_p,  # pResponse : MESSAGEBOX_RESULT* out
    wintypes.BOOL,  # bWait : BOOL
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('WTSAPI32.dll')
WTSSendMessageW = Fiddle::Function.new(
  lib['WTSSendMessageW'],
  [
    Fiddle::TYPE_VOIDP,  # hServer : HANDLE optional
    -Fiddle::TYPE_INT,  # SessionId : DWORD
    Fiddle::TYPE_VOIDP,  # pTitle : LPWSTR
    -Fiddle::TYPE_INT,  # TitleLength : DWORD
    Fiddle::TYPE_VOIDP,  # pMessage : LPWSTR
    -Fiddle::TYPE_INT,  # MessageLength : DWORD
    -Fiddle::TYPE_INT,  # Style : MESSAGEBOX_STYLE
    -Fiddle::TYPE_INT,  # Timeout : DWORD
    Fiddle::TYPE_VOIDP,  # pResponse : MESSAGEBOX_RESULT* out
    Fiddle::TYPE_INT,  # bWait : BOOL
  ],
  Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "wtsapi32")]
extern "system" {
    fn WTSSendMessageW(
        hServer: *mut core::ffi::c_void,  // HANDLE optional
        SessionId: u32,  // DWORD
        pTitle: *mut u16,  // LPWSTR
        TitleLength: u32,  // DWORD
        pMessage: *mut u16,  // LPWSTR
        MessageLength: u32,  // DWORD
        Style: u32,  // MESSAGEBOX_STYLE
        Timeout: u32,  // DWORD
        pResponse: *mut i32,  // MESSAGEBOX_RESULT* out
        bWait: i32  // BOOL
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("WTSAPI32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern bool WTSSendMessageW(IntPtr hServer, uint SessionId, [MarshalAs(UnmanagedType.LPWStr)] string pTitle, uint TitleLength, [MarshalAs(UnmanagedType.LPWStr)] string pMessage, uint MessageLength, uint Style, uint Timeout, out int pResponse, bool bWait);
"@
$api = Add-Type -MemberDefinition $sig -Name 'WTSAPI32_WTSSendMessageW' -Namespace Win32 -PassThru
# $api::WTSSendMessageW(hServer, SessionId, pTitle, TitleLength, pMessage, MessageLength, Style, Timeout, pResponse, bWait)

#uselib "WTSAPI32.dll"
#func global WTSSendMessageW "WTSSendMessageW" wptr, wptr, wptr, wptr, wptr, wptr, wptr, wptr, wptr, wptr
; WTSSendMessageW hServer, SessionId, pTitle, TitleLength, pMessage, MessageLength, Style, Timeout, pResponse, bWait   ; 戻り値は stat
; hServer : HANDLE optional -> "wptr"
; SessionId : DWORD -> "wptr"
; pTitle : LPWSTR -> "wptr"
; TitleLength : DWORD -> "wptr"
; pMessage : LPWSTR -> "wptr"
; MessageLength : DWORD -> "wptr"
; Style : MESSAGEBOX_STYLE -> "wptr"
; Timeout : DWORD -> "wptr"
; pResponse : MESSAGEBOX_RESULT* out -> "wptr"
; bWait : BOOL -> "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 "WTSAPI32.dll"
#cfunc global WTSSendMessageW "WTSSendMessageW" sptr, int, wstr, int, wstr, int, int, int, int, int
; res = WTSSendMessageW(hServer, SessionId, pTitle, TitleLength, pMessage, MessageLength, Style, Timeout, pResponse, bWait)
; hServer : HANDLE optional -> "sptr"
; SessionId : DWORD -> "int"
; pTitle : LPWSTR -> "wstr"
; TitleLength : DWORD -> "int"
; pMessage : LPWSTR -> "wstr"
; MessageLength : DWORD -> "int"
; Style : MESSAGEBOX_STYLE -> "int"
; Timeout : DWORD -> "int"
; pResponse : MESSAGEBOX_RESULT* out -> "int"
; bWait : BOOL -> "int"

; BOOL WTSSendMessageW(HANDLE hServer, DWORD SessionId, LPWSTR pTitle, DWORD TitleLength, LPWSTR pMessage, DWORD MessageLength, MESSAGEBOX_STYLE Style, DWORD Timeout, MESSAGEBOX_RESULT* pResponse, BOOL bWait)
#uselib "WTSAPI32.dll"
#cfunc global WTSSendMessageW "WTSSendMessageW" intptr, int, wstr, int, wstr, int, int, int, int, int
; res = WTSSendMessageW(hServer, SessionId, pTitle, TitleLength, pMessage, MessageLength, Style, Timeout, pResponse, bWait)
; hServer : HANDLE optional -> "intptr"
; SessionId : DWORD -> "int"
; pTitle : LPWSTR -> "wstr"
; TitleLength : DWORD -> "int"
; pMessage : LPWSTR -> "wstr"
; MessageLength : DWORD -> "int"
; Style : MESSAGEBOX_STYLE -> "int"
; Timeout : DWORD -> "int"
; pResponse : MESSAGEBOX_RESULT* out -> "int"
; bWait : BOOL -> "int"

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

var (
	wtsapi32 = windows.NewLazySystemDLL("WTSAPI32.dll")
	procWTSSendMessageW = wtsapi32.NewProc("WTSSendMessageW")
)

// hServer (HANDLE optional), SessionId (DWORD), pTitle (LPWSTR), TitleLength (DWORD), pMessage (LPWSTR), MessageLength (DWORD), Style (MESSAGEBOX_STYLE), Timeout (DWORD), pResponse (MESSAGEBOX_RESULT* out), bWait (BOOL)
r1, _, err := procWTSSendMessageW.Call(
	uintptr(hServer),
	uintptr(SessionId),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(pTitle))),
	uintptr(TitleLength),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(pMessage))),
	uintptr(MessageLength),
	uintptr(Style),
	uintptr(Timeout),
	uintptr(pResponse),
	uintptr(bWait),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function WTSSendMessageW(
  hServer: THandle;   // HANDLE optional
  SessionId: DWORD;   // DWORD
  pTitle: PWideChar;   // LPWSTR
  TitleLength: DWORD;   // DWORD
  pMessage: PWideChar;   // LPWSTR
  MessageLength: DWORD;   // DWORD
  Style: DWORD;   // MESSAGEBOX_STYLE
  Timeout: DWORD;   // DWORD
  pResponse: Pointer;   // MESSAGEBOX_RESULT* out
  bWait: BOOL   // BOOL
): BOOL; stdcall;
  external 'WTSAPI32.dll' name 'WTSSendMessageW';

result := DllCall("WTSAPI32\WTSSendMessageW"
    , "Ptr", hServer   ; HANDLE optional
    , "UInt", SessionId   ; DWORD
    , "WStr", pTitle   ; LPWSTR
    , "UInt", TitleLength   ; DWORD
    , "WStr", pMessage   ; LPWSTR
    , "UInt", MessageLength   ; DWORD
    , "UInt", Style   ; MESSAGEBOX_STYLE
    , "UInt", Timeout   ; DWORD
    , "Ptr", pResponse   ; MESSAGEBOX_RESULT* out
    , "Int", bWait   ; BOOL
    , "Int")   ; return: BOOL

●WTSSendMessageW(hServer, SessionId, pTitle, TitleLength, pMessage, MessageLength, Style, Timeout, pResponse, bWait) = DLL("WTSAPI32.dll", "bool WTSSendMessageW(void*, dword, char*, dword, char*, dword, dword, dword, void*, bool)")
# 呼び出し: WTSSendMessageW(hServer, SessionId, pTitle, TitleLength, pMessage, MessageLength, Style, Timeout, pResponse, bWait)
# hServer : HANDLE optional -> "void*"
# SessionId : DWORD -> "dword"
# pTitle : LPWSTR -> "char*"
# TitleLength : DWORD -> "dword"
# pMessage : LPWSTR -> "char*"
# MessageLength : DWORD -> "dword"
# Style : MESSAGEBOX_STYLE -> "dword"
# Timeout : DWORD -> "dword"
# pResponse : MESSAGEBOX_RESULT* out -> "void*"
# bWait : BOOL -> "bool"
# 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。