RegDeleteValueA

// ADVAPI32.dll  (ANSI / -A)
#include <windows.h>

WIN32_ERROR RegDeleteValueA(
    HKEY hKey,
    LPCSTR lpValueName   // optional
);

<DllImport("ADVAPI32.dll", CharSet:=CharSet.Ansi, ExactSpelling:=True)>
Public Shared Function RegDeleteValueA(
    hKey As IntPtr,   ' HKEY
    <MarshalAs(UnmanagedType.LPStr)> lpValueName As String   ' LPCSTR optional
) As UInteger
End Function

' hKey : HKEY
' lpValueName : LPCSTR optional
Declare PtrSafe Function RegDeleteValueA Lib "advapi32" ( _
    ByVal hKey As LongPtr, _
    ByVal lpValueName As String) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

RegDeleteValueA = ctypes.windll.advapi32.RegDeleteValueA
RegDeleteValueA.restype = wintypes.DWORD
RegDeleteValueA.argtypes = [
    wintypes.HANDLE,  # hKey : HKEY
    wintypes.LPCSTR,  # lpValueName : LPCSTR optional
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('ADVAPI32.dll')
RegDeleteValueA = Fiddle::Function.new(
  lib['RegDeleteValueA'],
  [
    Fiddle::TYPE_VOIDP,  # hKey : HKEY
    Fiddle::TYPE_VOIDP,  # lpValueName : LPCSTR optional
  ],
  -Fiddle::TYPE_INT)

#[link(name = "advapi32")]
extern "system" {
    fn RegDeleteValueA(
        hKey: *mut core::ffi::c_void,  // HKEY
        lpValueName: *const u8  // LPCSTR optional
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("ADVAPI32.dll", CharSet = CharSet.Ansi)]
public static extern uint RegDeleteValueA(IntPtr hKey, [MarshalAs(UnmanagedType.LPStr)] string lpValueName);
"@
$api = Add-Type -MemberDefinition $sig -Name 'ADVAPI32_RegDeleteValueA' -Namespace Win32 -PassThru
# $api::RegDeleteValueA(hKey, lpValueName)

#uselib "ADVAPI32.dll"
#func global RegDeleteValueA "RegDeleteValueA" sptr, sptr
; RegDeleteValueA hKey, lpValueName   ; 戻り値は stat
; hKey : HKEY -> "sptr"
; lpValueName : LPCSTR optional -> "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 "ADVAPI32.dll"
#cfunc global RegDeleteValueA "RegDeleteValueA" sptr, str
; res = RegDeleteValueA(hKey, lpValueName)
; hKey : HKEY -> "sptr"
; lpValueName : LPCSTR optional -> "str"

; WIN32_ERROR RegDeleteValueA(HKEY hKey, LPCSTR lpValueName)
#uselib "ADVAPI32.dll"
#cfunc global RegDeleteValueA "RegDeleteValueA" intptr, str
; res = RegDeleteValueA(hKey, lpValueName)
; hKey : HKEY -> "intptr"
; lpValueName : LPCSTR optional -> "str"

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

var (
	advapi32 = windows.NewLazySystemDLL("ADVAPI32.dll")
	procRegDeleteValueA = advapi32.NewProc("RegDeleteValueA")
)

// hKey (HKEY), lpValueName (LPCSTR optional)
r1, _, err := procRegDeleteValueA.Call(
	uintptr(hKey),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(lpValueName))),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // WIN32_ERROR

function RegDeleteValueA(
  hKey: THandle;   // HKEY
  lpValueName: PAnsiChar   // LPCSTR optional
): DWORD; stdcall;
  external 'ADVAPI32.dll' name 'RegDeleteValueA';

result := DllCall("ADVAPI32\RegDeleteValueA"
    , "Ptr", hKey   ; HKEY
    , "AStr", lpValueName   ; LPCSTR optional
    , "UInt")   ; return: WIN32_ERROR

●RegDeleteValueA(hKey, lpValueName) = DLL("ADVAPI32.dll", "dword RegDeleteValueA(void*, char*)")
# 呼び出し: RegDeleteValueA(hKey, lpValueName)
# hKey : HKEY -> "void*"
# lpValueName : LPCSTR optional -> "char*"
# 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)。

const std = @import("std");

extern "advapi32" fn RegDeleteValueA(
    hKey: ?*anyopaque, // HKEY
    lpValueName: [*c]const u8 // LPCSTR optional
) callconv(std.os.windows.WINAPI) u32;

proc RegDeleteValueA(
    hKey: pointer,  # HKEY
    lpValueName: cstring  # LPCSTR optional
): uint32 {.importc: "RegDeleteValueA", stdcall, dynlib: "ADVAPI32.dll".}

pragma(lib, "advapi32");
extern(Windows)
uint RegDeleteValueA(
    void* hKey,   // HKEY
    const(char)* lpValueName   // LPCSTR optional
);

ccall((:RegDeleteValueA, "ADVAPI32.dll"), stdcall, UInt32,
      (Ptr{Cvoid}, Cstring),
      hKey, lpValueName)
# hKey : HKEY -> Ptr{Cvoid}
# lpValueName : LPCSTR optional -> Cstring
# stdcall は 32bit のみ意味を持つ(x64 では無視)。

local ffi = require("ffi")
ffi.cdef[[
uint32_t RegDeleteValueA(
    void* hKey,
    const char* lpValueName);
]]
local advapi32 = ffi.load("advapi32")
-- advapi32.RegDeleteValueA(hKey, lpValueName)
-- hKey : HKEY
-- lpValueName : LPCSTR optional
-- 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。

const koffi = require('koffi');
const lib = koffi.load('ADVAPI32.dll');
const RegDeleteValueA = lib.func('__stdcall', 'RegDeleteValueA', 'uint32_t', ['void *', 'str']);
// RegDeleteValueA(hKey, lpValueName)
// hKey : HKEY -> 'void *'
// lpValueName : LPCSTR optional -> 'str'
// 出力ポインタは koffi.out(...) で包む。構造体は koffi.struct で定義。

const lib = Deno.dlopen("ADVAPI32.dll", {
  RegDeleteValueA: { parameters: ["pointer", "buffer"], result: "u32" },
});
// lib.symbols.RegDeleteValueA(hKey, lpValueName)
// hKey : HKEY -> "pointer"
// lpValueName : LPCSTR optional -> "buffer"
// 文字列は "buffer"。ANSI(-A) は new TextEncoder() で UTF-8/ANSI バイト列(末尾に \x00)を渡す。
// 値渡し構造体は { struct: [ ...field types... ] } を使用。

<?php
$ffi = FFI::cdef(<<<C
uint32_t RegDeleteValueA(
    void* hKey,
    const char* lpValueName);
C, "ADVAPI32.dll");
// $ffi->RegDeleteValueA(hKey, lpValueName);
// hKey : HKEY
// lpValueName : LPCSTR optional
// 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。
// WINAPI(stdcall): x64 では呼出規約が統一されるため問題なし。x86 では __stdcall 対応のラッパが必要な場合あり。

import com.sun.jna.*;
import com.sun.jna.ptr.*;
import com.sun.jna.win32.StdCallLibrary;
import com.sun.jna.win32.W32APIOptions;

public interface Advapi32 extends StdCallLibrary {
    Advapi32 INSTANCE = Native.load("advapi32", Advapi32.class, W32APIOptions.ASCII_OPTIONS);
    int RegDeleteValueA(
        Pointer hKey,   // HKEY
        String lpValueName   // LPCSTR optional
    );
}

@[Link("advapi32")]
lib LibADVAPI32
  fun RegDeleteValueA = RegDeleteValueA(
    hKey : Void*,   # HKEY
    lpValueName : UInt8*   # LPCSTR optional
  ) : UInt32
end
# 構造体/GUID/enum は lib 内に対応する型定義が必要。
# 呼出規約: x64 は規約統一のため OK。x86(32bit)は WINAPI=stdcall だが Crystal の fun に stdcall 付与構文がなく非対応。

import 'dart:ffi';
import 'package:ffi/ffi.dart';

typedef RegDeleteValueANative = Uint32 Function(Pointer<Void>, Pointer<Utf8>);
typedef RegDeleteValueADart = int Function(Pointer<Void>, Pointer<Utf8>);
final RegDeleteValueA = DynamicLibrary.open('ADVAPI32.dll')
    .lookupFunction<RegDeleteValueANative, RegDeleteValueADart>('RegDeleteValueA');
// hKey : HKEY -> Pointer<Void>
// lpValueName : LPCSTR optional -> Pointer<Utf8>
// 文字列は package:ffi の "...".toNativeUtf16()/toNativeUtf8() で変換。

{$mode objfpc}{$H+}
function RegDeleteValueA(
  hKey: THandle;   // HKEY
  lpValueName: PAnsiChar   // LPCSTR optional
): DWORD; stdcall;
  external 'ADVAPI32.dll' name 'RegDeleteValueA';

import Foreign
import Foreign.C.Types
import Foreign.C.String

foreign import stdcall safe "RegDeleteValueA"
  c_RegDeleteValueA :: Ptr () -> CString -> IO Word32
-- hKey : HKEY -> Ptr ()
-- lpValueName : LPCSTR optional -> CString
-- 要 GHC(Windows)。stdcall は x64 では ccall として扱われる。ブロックする API は safe 呼び出し推奨。

open Ctypes
open Foreign

let regdeletevaluea =
  foreign "RegDeleteValueA"
    ((ptr void) @-> string @-> returning uint32_t)
(* hKey : HKEY -> (ptr void) *)
(* lpValueName : LPCSTR optional -> string *)
(* foreign は cdecl 前提。x64 Windows では WINAPI と一致。構造体は ctypes structure を定義のこと。 *)

(cffi:define-foreign-library advapi32 (t "ADVAPI32.dll"))
(cffi:use-foreign-library advapi32)

(cffi:defcfun ("RegDeleteValueA" reg-delete-value-a :convention :stdcall) :uint32
  (h-key :pointer)   ; HKEY
  (lp-value-name :string))   ; LPCSTR optional
; isize/usize(INT_PTR/SIZE_T)は x64 前提で :int64/:uint64。x86 では :int32/:uint32。

use Win32::API;
my $RegDeleteValueA = Win32::API::More->new('ADVAPI32',
    'DWORD RegDeleteValueA(HANDLE hKey, LPCSTR lpValueName)');
# my $ret = $RegDeleteValueA->Call($hKey, $lpValueName);
# hKey : HKEY -> HANDLE
# lpValueName : LPCSTR optional -> LPCSTR
# 値渡し構造体は pack() した文字列、または Win32::API::Struct を使用。