NMBCDROPDOWN

using System;
using System.Runtime.InteropServices;

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct NMHDR
{
    public IntPtr hwndFrom;
    public UIntPtr idFrom;
    public uint code;
}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct RECT
{
    public int left;
    public int top;
    public int right;
    public int bottom;
}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct NMBCDROPDOWN
{
    public NMHDR hdr;
    public RECT rcButton;
}

Imports System.Runtime.InteropServices

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)>
Public Structure NMHDR
    Public hwndFrom As IntPtr
    Public idFrom As UIntPtr
    Public code As UInteger
End Structure

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)>
Public Structure RECT
    Public left As Integer
    Public top As Integer
    Public right As Integer
    Public bottom As Integer
End Structure

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)>
Public Structure NMBCDROPDOWN
    Public hdr As NMHDR
    Public rcButton As RECT
End Structure

import ctypes
from ctypes import wintypes

class NMHDR(ctypes.Structure):
    _fields_ = [
        ("hwndFrom", ctypes.c_void_p),
        ("idFrom", ctypes.c_size_t),
        ("code", wintypes.DWORD),
    ]

class RECT(ctypes.Structure):
    _fields_ = [
        ("left", ctypes.c_int),
        ("top", ctypes.c_int),
        ("right", ctypes.c_int),
        ("bottom", ctypes.c_int),
    ]

class NMBCDROPDOWN(ctypes.Structure):
    _fields_ = [
        ("hdr", NMHDR),
        ("rcButton", RECT),
    ]

#[repr(C)]
pub struct NMHDR {
    pub hwndFrom: *mut core::ffi::c_void,
    pub idFrom: usize,
    pub code: u32,
}

#[repr(C)]
pub struct RECT {
    pub left: i32,
    pub top: i32,
    pub right: i32,
    pub bottom: i32,
}

#[repr(C)]
pub struct NMBCDROPDOWN {
    pub hdr: NMHDR,
    pub rcButton: RECT,
}

import "golang.org/x/sys/windows"

type NMHDR struct {
	hwndFrom uintptr
	idFrom uintptr
	code uint32
}

type RECT struct {
	left int32
	top int32
	right int32
	bottom int32
}

type NMBCDROPDOWN struct {
	hdr NMHDR
	rcButton RECT
}

type
  NMHDR = record
    hwndFrom: Pointer;
    idFrom: NativeUInt;
    code: DWORD;
  end;

  RECT = record
    left: Integer;
    top: Integer;
    right: Integer;
    bottom: Integer;
  end;

  NMBCDROPDOWN = record
    hdr: NMHDR;
    rcButton: RECT;
  end;

const NMHDR = extern struct {
    hwndFrom: ?*anyopaque,
    idFrom: usize,
    code: u32,
};

const RECT = extern struct {
    left: i32,
    top: i32,
    right: i32,
    bottom: i32,
};

const NMBCDROPDOWN = extern struct {
    hdr: NMHDR,
    rcButton: RECT,
};

type
  NMHDR {.bycopy.} = object
    hwndFrom: pointer
    idFrom: uint
    code: uint32

  RECT {.bycopy.} = object
    left: int32
    top: int32
    right: int32
    bottom: int32

  NMBCDROPDOWN {.bycopy.} = object
    hdr: NMHDR
    rcButton: RECT

struct NMHDR
{
    void* hwndFrom;
    size_t idFrom;
    uint code;
}

struct RECT
{
    int left;
    int top;
    int right;
    int bottom;
}

struct NMBCDROPDOWN
{
    NMHDR hdr;
    RECT rcButton;
}