Python 3：在Windows中檢測顯示器電源狀態

Question

我需要我的python腳本來獲取Windows顯示器的電源狀態。

根據StackOverflow中的此鏈接，我可以使用RegisterPowerSettingNotification來獲取GUID_MONITOR_POWER_ON但是我不知道如何實現它。 目的是在屏幕關閉時觸發事件。

我可以通過ctypes.windll.user32.RegisterPowerSettingNotification訪問該ctypes.windll.user32.RegisterPowerSettingNotification但是我需要幫助才能調用它並獲取消息

RegisterPowerSettingNotification
電源設置GUID

我正在運行Windows 10和Python 3

---

更新 ：

我能夠調用並注冊窗口以接收消息，但仍然無法從中獲取所需的信息...我知道lparam是指向結構的指針，但我需要從中獲取信息，例如GUID電源設置和數據字段

import win32con
import win32api
import win32gui
import sys
import time
from ctypes import POINTER, windll
from comtypes import GUID
from ctypes.wintypes import HANDLE, DWORD

PBT_POWERSETTINGCHANGE = 0x8013

def log_info(msg):
    """ Prints """
    print(msg)
    f = open("test.log", "a+")
    f.write(msg + "\n")
    f.close()

def wndproc(hwnd, msg, wparam, lparam):
    print('.')
    log_info("wndproc: %s\nw: %s\nl: %s" % (msg, wparam, lparam))
    if msg == win32con.WM_POWERBROADCAST:
        if wparam == win32con.PBT_APMPOWERSTATUSCHANGE:
            log_info('Power status has changed')
        if wparam == win32con.PBT_APMRESUMEAUTOMATIC:
            log_info('System resume')
        if wparam == win32con.PBT_APMRESUMESUSPEND:
            log_info('System resume by user input')
        if wparam == win32con.PBT_APMSUSPEND:
            log_info('System suspend')
        if wparam == PBT_POWERSETTINGCHANGE:
            log_info('Power setting changed...')
            #lparam is pointer to structure i need

if __name__ == "__main__":
    log_info("*** STARTING ***")
    hinst = win32api.GetModuleHandle(None)
    wndclass = win32gui.WNDCLASS()
    wndclass.hInstance = hinst
    wndclass.lpszClassName = "testWindowClass"
    messageMap = { win32con.WM_POWERBROADCAST : wndproc }

    wndclass.lpfnWndProc = messageMap

    try:
        myWindowClass = win32gui.RegisterClass(wndclass)
        hwnd = win32gui.CreateWindowEx(win32con.WS_EX_LEFT,
                                     myWindowClass, 
                                     "testMsgWindow", 
                                     0, 
                                     0, 
                                     0, 
                                     win32con.CW_USEDEFAULT, 
                                     win32con.CW_USEDEFAULT, 
                                     0, 
                                     0, 
                                     hinst, 
                                     None)
    except Exception as e:
        log_info("Exception: %s" % str(e))


    if hwnd is None:
        log_info("hwnd is none!")
    else:
        log_info("hwnd: %s" % hwnd)

    register_function = windll.user32.RegisterPowerSettingNotification

    guids_info = {
                    'GUID_MONITOR_POWER_ON' : '{02731015-4510-4526-99e6-e5a17ebd1aea}',
                    'GUID_SYSTEM_AWAYMODE' : '{98a7f580-01f7-48aa-9c0f-44352c29e5C0}',
                    'fake' : '{98a7f580-01f7-48aa-9c0f-44352c29e555}' # just to see if I get an error or a different return from function
                 }

    hwnd_pointer = HANDLE(hwnd)
    for name, guid_info in guids_info.items():
        result = register_function(hwnd_pointer, GUID(guid_info), DWORD(0))
        print('registering', name)
        print('result:', result) # result is pointer to unregister function if I'm not mistaken
        print()

    print('\nEntering loop')
    while True:
        win32gui.PumpWaitingMessages()
        time.sleep(1)

Answer 1

為了使代碼正常工作，需要有powerbroadcast_setting結構，帶有CFUNCTYPE ctypes中的函數聲明以及從lparam到powerbroadcast_setting

完整的工作代碼：

import win32con
import win32api
import win32gui
import time
from ctypes import POINTER, windll, Structure, cast, CFUNCTYPE, c_int, c_uint, c_void_p, c_bool
from comtypes import GUID
from ctypes.wintypes import HANDLE, DWORD


PBT_POWERSETTINGCHANGE = 0x8013
GUID_CONSOLE_DISPLAY_STATE = '{6FE69556-704A-47A0-8F24-C28D936FDA47}'
GUID_ACDC_POWER_SOURCE = '{5D3E9A59-E9D5-4B00-A6BD-FF34FF516548}'
GUID_BATTERY_PERCENTAGE_REMAINING = '{A7AD8041-B45A-4CAE-87A3-EECBB468A9E1}'
GUID_MONITOR_POWER_ON = '{02731015-4510-4526-99E6-E5A17EBD1AEA}'
GUID_SYSTEM_AWAYMODE = '{98A7F580-01F7-48AA-9C0F-44352C29E5C0}'


class POWERBROADCAST_SETTING(Structure):
    _fields_ = [("PowerSetting", GUID),
                ("DataLength", DWORD),
                ("Data", DWORD)]


def wndproc(hwnd, msg, wparam, lparam):
    if msg == win32con.WM_POWERBROADCAST:
        if wparam == win32con.PBT_APMPOWERSTATUSCHANGE:
            print('Power status has changed')
        if wparam == win32con.PBT_APMRESUMEAUTOMATIC:
            print('System resume')
        if wparam == win32con.PBT_APMRESUMESUSPEND:
            print('System resume by user input')
        if wparam == win32con.PBT_APMSUSPEND:
            print('System suspend')
        if wparam == PBT_POWERSETTINGCHANGE:
            print('Power setting changed...')
            settings = cast(lparam, POINTER(POWERBROADCAST_SETTING)).contents
            power_setting = str(settings.PowerSetting)
            data_length = settings.DataLength
            data = settings.Data
            if power_setting == GUID_CONSOLE_DISPLAY_STATE:
                if data == 0: print('Display off')
                if data == 1: print('Display on')
                if data == 2: print('Display dimmed')
            elif power_setting == GUID_ACDC_POWER_SOURCE:
                if data == 0: print('AC power')
                if data == 1: print('Battery power')
                if data == 2: print('Short term power')
            elif power_setting == GUID_BATTERY_PERCENTAGE_REMAINING:
                print('battery remaining: %s' % data)
            elif power_setting == GUID_MONITOR_POWER_ON:
                if data == 0: print('Monitor off')
                if data == 1: print('Monitor on')
            elif power_setting == GUID_SYSTEM_AWAYMODE:
                if data == 0: print('Exiting away mode')
                if data == 1: print('Entering away mode')
            else:
                print('unknown GUID')
        return True

    return False




if __name__ == "__main__":
    print("*** STARTING ***")
    hinst = win32api.GetModuleHandle(None)
    wndclass = win32gui.WNDCLASS()
    wndclass.hInstance = hinst
    wndclass.lpszClassName = "testWindowClass"
    CMPFUNC = CFUNCTYPE(c_bool, c_int, c_uint, c_uint, c_void_p)
    wndproc_pointer = CMPFUNC(wndproc)
    wndclass.lpfnWndProc = {win32con.WM_POWERBROADCAST : wndproc_pointer}
    try:
        myWindowClass = win32gui.RegisterClass(wndclass)
        hwnd = win32gui.CreateWindowEx(win32con.WS_EX_LEFT,
                                     myWindowClass, 
                                     "testMsgWindow", 
                                     0, 
                                     0, 
                                     0, 
                                     win32con.CW_USEDEFAULT, 
                                     win32con.CW_USEDEFAULT, 
                                     0, 
                                     0, 
                                     hinst, 
                                     None)
    except Exception as e:
        print("Exception: %s" % str(e))

    if hwnd is None:
        print("hwnd is none!")
    else:
        print("hwnd: %s" % hwnd)

    guids_info = {
                    'GUID_MONITOR_POWER_ON' : GUID_MONITOR_POWER_ON,
                    'GUID_SYSTEM_AWAYMODE' : GUID_SYSTEM_AWAYMODE,
                    'GUID_CONSOLE_DISPLAY_STATE' : GUID_CONSOLE_DISPLAY_STATE,
                    'GUID_ACDC_POWER_SOURCE' : GUID_ACDC_POWER_SOURCE,
                    'GUID_BATTERY_PERCENTAGE_REMAINING' : GUID_BATTERY_PERCENTAGE_REMAINING
                 }
    for name, guid_info in guids_info.items():
        result = windll.user32.RegisterPowerSettingNotification(HANDLE(hwnd), GUID(guid_info), DWORD(0))
        print('registering', name)
        print('result:', hex(result))
        print('lastError:', win32api.GetLastError())
        print()

    print('\nEntering loop')
    while True:
        win32gui.PumpWaitingMessages()
        time.sleep(1)