BufferedPaintSetAlpha

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

HRESULT BufferedPaintSetAlpha(
    INT_PTR hBufferedPaint,
    const RECT* prc,   // optional
    BYTE alpha
);

<DllImport("UxTheme.dll", ExactSpelling:=True)>
Public Shared Function BufferedPaintSetAlpha(
    hBufferedPaint As IntPtr,   ' INT_PTR
    prc As IntPtr,   ' RECT* optional
    alpha As Byte   ' BYTE
) As Integer
End Function

' hBufferedPaint : INT_PTR
' prc : RECT* optional
' alpha : BYTE
Declare PtrSafe Function BufferedPaintSetAlpha Lib "uxtheme" ( _
    ByVal hBufferedPaint As LongPtr, _
    ByVal prc As LongPtr, _
    ByVal alpha As Byte) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

BufferedPaintSetAlpha = ctypes.windll.uxtheme.BufferedPaintSetAlpha
BufferedPaintSetAlpha.restype = ctypes.c_int
BufferedPaintSetAlpha.argtypes = [
    ctypes.c_ssize_t,  # hBufferedPaint : INT_PTR
    ctypes.c_void_p,  # prc : RECT* optional
    ctypes.c_ubyte,  # alpha : BYTE
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('UxTheme.dll')
BufferedPaintSetAlpha = Fiddle::Function.new(
  lib['BufferedPaintSetAlpha'],
  [
    Fiddle::TYPE_INTPTR_T,  # hBufferedPaint : INT_PTR
    Fiddle::TYPE_VOIDP,  # prc : RECT* optional
    -Fiddle::TYPE_CHAR,  # alpha : BYTE
  ],
  Fiddle::TYPE_INT)

#[link(name = "uxtheme")]
extern "system" {
    fn BufferedPaintSetAlpha(
        hBufferedPaint: isize,  // INT_PTR
        prc: *const RECT,  // RECT* optional
        alpha: u8  // BYTE
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("UxTheme.dll")]
public static extern int BufferedPaintSetAlpha(IntPtr hBufferedPaint, IntPtr prc, byte alpha);
"@
$api = Add-Type -MemberDefinition $sig -Name 'UxTheme_BufferedPaintSetAlpha' -Namespace Win32 -PassThru
# $api::BufferedPaintSetAlpha(hBufferedPaint, prc, alpha)

#uselib "UxTheme.dll"
#func global BufferedPaintSetAlpha "BufferedPaintSetAlpha" sptr, sptr, sptr
; BufferedPaintSetAlpha hBufferedPaint, varptr(prc), alpha   ; 戻り値は stat
; hBufferedPaint : INT_PTR -> "sptr"
; prc : RECT* optional -> "sptr"
; alpha : BYTE -> "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 "UxTheme.dll"
#cfunc global BufferedPaintSetAlpha "BufferedPaintSetAlpha" sptr, var, int
; res = BufferedPaintSetAlpha(hBufferedPaint, prc, alpha)
; hBufferedPaint : INT_PTR -> "sptr"
; prc : RECT* optional -> "var"
; alpha : BYTE -> "int"
; ※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 BufferedPaintSetAlpha(INT_PTR hBufferedPaint, RECT* prc, BYTE alpha)
#uselib "UxTheme.dll"
#cfunc global BufferedPaintSetAlpha "BufferedPaintSetAlpha" intptr, var, int
; res = BufferedPaintSetAlpha(hBufferedPaint, prc, alpha)
; hBufferedPaint : INT_PTR -> "intptr"
; prc : RECT* optional -> "var"
; alpha : BYTE -> "int"
; ※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 (
	uxtheme = windows.NewLazySystemDLL("UxTheme.dll")
	procBufferedPaintSetAlpha = uxtheme.NewProc("BufferedPaintSetAlpha")
)

// hBufferedPaint (INT_PTR), prc (RECT* optional), alpha (BYTE)
r1, _, err := procBufferedPaintSetAlpha.Call(
	uintptr(hBufferedPaint),
	uintptr(prc),
	uintptr(alpha),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function BufferedPaintSetAlpha(
  hBufferedPaint: NativeInt;   // INT_PTR
  prc: Pointer;   // RECT* optional
  alpha: Byte   // BYTE
): Integer; stdcall;
  external 'UxTheme.dll' name 'BufferedPaintSetAlpha';

result := DllCall("UxTheme\BufferedPaintSetAlpha"
    , "Ptr", hBufferedPaint   ; INT_PTR
    , "Ptr", prc   ; RECT* optional
    , "UChar", alpha   ; BYTE
    , "Int")   ; return: HRESULT

●BufferedPaintSetAlpha(hBufferedPaint, prc, alpha) = DLL("UxTheme.dll", "int BufferedPaintSetAlpha(int, void*, byte)")
# 呼び出し: BufferedPaintSetAlpha(hBufferedPaint, prc, alpha)
# hBufferedPaint : INT_PTR -> "int"
# prc : RECT* optional -> "void*"
# alpha : BYTE -> "byte"
# 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)。