用python的ctypes模块监控Windows电脑是否按下电源键

可以使用 ctypes 模块调用 Windows API 来监控电源键的按下事件。具体步骤如下：

1. 导入 ctypes 模块，定义一些常量和数据结构：

import ctypes

# Windows API 常量
WM_POWERBROADCAST = 0x0218
PBT_POWERSETTINGCHANGE = 0x8013
GUID_CONSOLE_DISPLAY_STATE = ctypes.wintypes.GUID(
    '{6fe69556-704a-47a0-8f24-c28d936fda47}')

# Windows API 数据结构
class POWERBROADCAST_SETTING(ctypes.Structure):
    _fields_ = [
        ('PowerSetting', ctypes.c_ulonglong),
        ('DataLength', ctypes.c_ulong),
        ('Data', ctypes.c_byte * 1)
    ]

2. 定义一个回调函数，当电源键按下时会被调用：

def power_callback(hwnd, msg, wparam, lparam):
    if msg == WM_POWERBROADCAST and wparam == PBT_POWERSETTINGCHANGE:
        power_setting = ctypes.cast(lparam, ctypes.POINTER(POWERBROADCAST_SETTING)).contents
        if power_setting.PowerSetting == GUID_CONSOLE_DISPLAY_STATE:
            display_state = ctypes.cast(ctypes.byref(power_setting.Data), ctypes.POINTER(ctypes.c_ulong)).contents.value
            if display_state == 0:
                print('电源键被按下')
    return True

3. 注册回调函数：

WINEVENT_OUTOFCONTEXT = 0x0000
WINEVENT_SKIPOWNTHREAD = 0x0001
WINEVENT_SKIPOWNPROCESS = 0x0002
WINEVENT_INCONTEXT = 0x0004

user32 = ctypes.windll.user32
user32.SetWinEventHook.restype = ctypes.wintypes.HANDLE
user32.SetWinEventHook.argtypes = [
    ctypes.wintypes.DWORD,
    ctypes.wintypes.DWORD,
    ctypes.wintypes.HMODULE,
    ctypes.WINFUNCTYPE(ctypes.wintypes.BOOL, ctypes.wintypes.HWND, ctypes.wintypes.DWORD, ctypes.wintypes.HWND, ctypes.wintypes.LONG)]

event_callback = ctypes.WINFUNCTYPE(ctypes.wintypes.BOOL, ctypes.wintypes.HWND, ctypes.wintypes.DWORD, ctypes.wintypes.HWND, ctypes.wintypes.LONG)(power_callback)
user32.SetWinEventHook(
    EVENT_SYSTEM_POWERSETTINGCHANGE,
    EVENT_SYSTEM_POWERSETTINGCHANGE,
    0,
    event_callback,
    0,
    0,
    WINEVENT_OUTOFCONTEXT | WINEVENT_SKIPOWNTHREAD | WINEVENT_SKIPOWNPROCESS)

4. 等待电源键的按下事件：

# 进入消息循环，等待回调函数被调用
msg = ctypes.wintypes.MSG()
while user32.GetMessageW(ctypes.byref(msg), 0, 0, 0) != 0:
    user32.TranslateMessageW(msg)
    user32.DispatchMessageW(msg)

完整代码如下：

import ctypes

# Windows API 常量
WM_POWERBROADCAST = 0x0218
PBT_POWERSETTINGCHANGE = 0x8013
GUID_CONSOLE_DISPLAY_STATE = ctypes.wintypes.GUID(
    '{6fe69556-704a-47a0-8f24-c28d936fda47}')

# Windows API 数据结构
class POWERBROADCAST_SETTING(ctypes.Structure):
    _fields_ = [
        ('PowerSetting', ctypes.c_ulonglong),
        ('DataLength', ctypes.c_ulong),
        ('Data', ctypes.c_byte * 1)
    ]

def power_callback(hwnd, msg, wparam, lparam):
    if msg == WM_POWERBROADCAST and wparam == PBT_POWERSETTINGCHANGE:
        power_setting = ctypes.cast(lparam, ctypes.POINTER(POWERBROADCAST_SETTING)).contents
        if power_setting.PowerSetting == GUID_CONSOLE_DISPLAY_STATE:
            display_state = ctypes.cast(ctypes.byref(power_setting.Data), ctypes.POINTER(ctypes.c_ulong)).contents.value
            if display_state == 0:
                print('电源键被按下')
    return True

WINEVENT_OUTOFCONTEXT = 0x0000
WINEVENT_SKIPOWNTHREAD = 0x0001
WINEVENT_SKIPOWNPROCESS = 0x0002
WINEVENT_INCONTEXT = 0x0004

user32 = ctypes.windll.user32
user32.SetWinEventHook.restype = ctypes.wintypes.HANDLE
user32.SetWinEventHook.argtypes = [
    ctypes.wintypes.DWORD,
    ctypes.wintypes.DWORD,
    ctypes.wintypes.HMODULE,
    ctypes.WINFUNCTYPE(ctypes.wintypes.BOOL, ctypes.wintypes.HWND, ctypes.wintypes.DWORD, ctypes.wintypes.HWND, ctypes.wintypes.LONG)]

event_callback = ctypes.WINFUNCTYPE(ctypes.wintypes.BOOL, ctypes.wintypes.HWND, ctypes.wintypes.DWORD, ctypes.wintypes.HWND, ctypes.wintypes.LONG)(power_callback)
user32.SetWinEventHook(
    EVENT_SYSTEM_POWERSETTINGCHANGE,
    EVENT_SYSTEM_POWERSETTINGCHANGE,
    0,
    event_callback,
    0,
    0,
    WINEVENT_OUTOFCONTEXT | WINEVENT_SKIPOWNTHREAD | WINEVENT_SKIPOWNPROCESS)

msg = ctypes.wintypes.MSG()
while user32.GetMessageW(ctypes.byref(msg), 0, 0, 0) != 0:
    user32.TranslateMessageW(msg)
    user32.DispatchMessageW(msg)