电源通知 RequestPowerNotifications

最新推荐文章于 2021-12-01 23:51:34 发布

转载最新推荐文章于 2021-12-01 23:51:34 发布 · 2.7k 阅读

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本文介绍了一个Windows应用程序如何通过使用RequestPowerNotifications API来监听系统电源状态的变化，并提供了完整的示例代码。该程序能够接收不同类型的电源通知，如系统状态转换、系统恢复等。

当系统的电源状态该变时，可以通过RequestPowerNotifications要求电源管理器向自己发送一个通知HANDLE RequestPowerNotifications( HANDLE hMsgQ, DWORD Flags );

示例：

#include <windows.h> #include <pm.h> #include <Winbase.h> #define MAX_NOTIFY_NAMELEN 128 #define PM_BROADCAST_QUEUE_SIZE ((sizeof(POWER_BROADCAST) + (MAX_NOTIFY_NAMELEN * sizeof(WCHAR) ) ) ) #define SIZEOFARRAY(a) (sizeof(a) / sizeof(a[0])) void IlockDThreadProc(void) { MSGQUEUEOPTIONS mqo; HANDLE hPowerMsgQ; HANDLE hPowerNotifications; DWORD cbRead; DWORD dwFlags; DWORD cbPowerMsgSize = PM_BROADCAST_QUEUE_SIZE; DWORD dwPwrFlags; TCHAR szPowerState[32]; POWER_BROADCAST ppb; union { WCHAR buf[PM_BROADCAST_QUEUE_SIZE]; POWER_BROADCAST powerBroadcast; } u; printf("IlockDThreadProc/n"); mqo.dwSize = sizeof(MSGQUEUEOPTIONS); mqo.dwFlags = MSGQUEUE_NOPRECOMMIT; mqo.dwMaxMessages = 32; mqo.cbMaxMessage = cbPowerMsgSize; mqo.bReadAccess = TRUE; hPowerMsgQ = CreateMsgQueue(NULL, &mqo); if (NULL == hPowerMsgQ) { printf("/r/n/r/nCreateMsgQueue failed: %x/n", GetLastError()); goto Error; } hPowerNotifications = RequestPowerNotifications(hPowerMsgQ, PBT_ALL); if (NULL == hPowerNotifications) { printf("RequestPowerNotifications failed: %x/n", GetLastError()); goto Error; } while(1) { WaitForSingleObject(hPowerMsgQ,INFINITE); if (!ReadMsgQueue(hPowerMsgQ, &u, cbPowerMsgSize, &cbRead, 0, &dwFlags)) { printf("ReadMsgQueue failed: %x/n", GetLastError()); ASSERT(FALSE); } ppb = u.powerBroadcast; switch(ppb.Message) { case PBT_TRANSITION: printf("##############################ppb.Message PBT_TRANSITION/n"); GetSystemPowerState(szPowerState,SIZEOFARRAY(szPowerState),&dwPwrFlags); if(!wcscmp(TEXT("backlightoff"),szPowerState)) { printf("BacklightOff/n"); break; } if(!wcscmp(TEXT("unattended"),szPowerState)) { printf("unattended/n"); break; } break; case PBT_RESUME: printf("##############################ppb.Message PBT_RESUME/n"); break; case PBT_POWERSTATUSCHANGE: printf("************************ppb.Message PBT_POWERSTATUSCHANGE/n"); break; case PBT_POWERINFOCHANGE: printf("##############################ppb.Message PBT_POWERINFOCHANGE/n"); break; default: printf("##############################ppb.Message default/n"); break; } } Error: if (hPowerMsgQ) CloseMsgQueue(hPowerMsgQ); if (hPowerNotifications) StopPowerNotifications(hPowerNotifications); } int _tmain(void) { CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)IlockDThreadProc,0,0,NULL); while(1) { Sleep(1000); } }

转自：http://blog.youkuaiyun.com/jmunic/archive/2009/10/26/4728172.aspx

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