//TITLE:
// WinCE实时获取电源状态变化
//AUTHOR:
// norains
//DATE:
// Friday 20-July-2007
//Environment:
// EVC4.0 + Windows CE 5.0 Standard SDK
//==================
使用CTpowerThread很简单实现实时获取电源的状态.在该类的内部创建了一个获取电量的线程,只要设置好回调函数,就可以自动接收设定间隔的电源状态.
现在我们来看看该类的具体操作方法:
//获取类的实例
CPowerThread *pPowThrd = CPowerThread::GetInstance();
if(pPowThrd != NULL)
{
//设置回调函数
pPowThrd->SetCallbackFunction(NotifyPowerStatus);
//启动线程,开始捕抓电量
pPowThrd->StartCapture();
}
这段代码中最重要的是设置回调函数,该函数的声明如下:
void NotifyPowerStatus(PowerStatusType powStatus, int iBatteryPercent)
powStatus是电源的简易状态,分为七个部分,取值为其中之一:
POW_UNKNOW, //Unknow the status
POW_CHARGING, //It's charging now
POW_CHARGEFULL, //Full charge
POW_VLOW, //The battery level is very low
POW_LOW,
POW_NORMAL,
POW_HIGH,
iBatteryPercent为当前电源的百分比,取值为:0~1.
下面给出一个回调函数的样例代码:
void NotifyPowerStatus(PowerStatusType powStatus, int iBatteryPercent)
{
switch(powStatus)
{
case POW_UNKNOW:
//当前状态不明
break;
case POW_CHARGING:
//充电中
break;
case POW_VLOW:
//电池电量非常低
break;
...
}
}
再来看看该类的其它接口函数:
SetWaitTime(ULONG ulTime)
该函数设置线程的超时时间.如果设置为INFINITE,则只有当电源状态有变化时才会调用回调函数.
GetCallbackFunction(void (* *pCallbackFunc)(PowerStatusType powStatus, int iBatteryPercent))
获取已设置的回调函数的指针
StopCapture()
停止线程.如果超时时间设为为INFINITE,则只有获取下次电源状态后才退出.
GetRunStatus()
获取当前线程的运行状态.
以下为该CPowerthread的完整源码:
源代码的具体原理可参考此篇文章:<EVC获取电源属性>http://blog.csdn.net/norains/archive/2006/09/07/1189157.aspx
//////////////////////////////////////////////////////////////////////
// PowerThread.h: interface for the CPowerThread class.
//
//Version:
// 1.0.1
//Date:
// 2007.07.20
//////////////////////////////////////////////////////////////////////
#ifndef POWERTHREAD_H
#define POWERTHREAD_H
#include "Pm.h"
//-----------------------------------------------------------------
//Enum data type
enum PowerStatusType
{
POW_UNKNOW, //Unknow the status
POW_CHARGING, //It's charging now
POW_CHARGEFULL, //Full charge
POW_VLOW, //The battery level is very low
POW_LOW,
POW_NORMAL,
POW_HIGH,
POW_VHIGH //The battery level is very high
};
//----------------------------------------------------------------
class CPowerThread
{
public:
void GetCallbackFunction(void (* *pCallbackFunc)(PowerStatusType powStatus, int iBatteryPercent));
void SetCallbackFunction(void (*pCallbackFunc)(PowerStatusType powStatus, int iBatteryPercent));
void StopCapture();
BOOL StartCapture();
BOOL GetRunStatus();
void SetTimeout(ULONG ulTime);
static CPowerThread * GetInstance();
virtual ~CPowerThread();
protected:
CPowerThread();
PowerStatusType GetPowerStatus(PPOWER_BROADCAST pPowerInfo, int *piPercent);
static DWORD WINAPI PowerThread(PVOID pArg);
static CPowerThread *m_pInstance;
BOOL m_bExitThread;
ULONG m_ulWaitTime;
BOOL m_bRunning;
CRITICAL_SECTION m_csLock;
//The critical section function
inline void InitLock() { InitializeCriticalSection(&m_csLock); }
inline void LockThis() { EnterCriticalSection(&m_csLock); }
inline void UnLockThis() { LeaveCriticalSection(&m_csLock); }
inline void DelLock() { DeleteCriticalSection(&m_csLock); }
//This is for callback function.
void (*m_pNotifyPower)(PowerStatusType powStatus, int iBatteryPercent);
};
#endif //#ifndef POWERTHREAD_H
//////////////////////////////////////////////////////////////////////
// PowerThread.cpp: implementation of the CPowerThread class.
//
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "PowerThread.h"
#include "Msgqueue.h"
//--------------------------------------------------------------------
//Macro define
#define DEFAULT_TIMEOUT 1000ms //1000ms
//---------------------------------------------------------------------
//Initialize
CPowerThread *CPowerThread::m_pInstance = NULL;
//----------------------------------------------------------------------
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
CPowerThread::CPowerThread():
m_bExitThread(TRUE),
m_ulWaitTime(DEFAULT_TIMEOUT),
m_bRunning(FALSE),
m_pNotifyPower(NULL)
{
InitLock();
}
CPowerThread::~CPowerThread()
{
if(m_pInstance != NULL)
{
delete m_pInstance;
m_pInstance = NULL;
}
DelLock();
}
//------------------------------------------------------------------
//Description:
// Get the level of power from the PPOWER_BROADCAST struct
//
//Parameters:
// pPowerInfo:[in] The struct includes the power information
// piPercent:[out] The battery life percent.
//
//Return Values:
// The power status
//----------------------------------------------------------------
PowerStatusType CPowerThread::GetPowerStatus(PPOWER_BROADCAST pPowerInfo, int *piPercent)
{
PowerStatusType powStatus = POW_UNKNOW;
if ( !pPowerInfo )
{
return POW_UNKNOW;
}
PPOWER_BROADCAST_POWER_INFO ppbpi = (PPOWER_BROADCAST_POWER_INFO) pPowerInfo->SystemPowerState;
if ( !ppbpi )
{
return POW_UNKNOW;
}
*piPercent = ppbpi->bBatteryLifePercent;
if(ppbpi->bACLineStatus == AC_LINE_ONLINE)
{
if(ppbpi->bBatteryFlag == BATTERY_FLAG_CHARGING)
{
//Charging
powStatus = POW_CHARGING;
}
else
{
//May be full charging,or may be no battery
powStatus = POW_CHARGEFULL;
}
}
else
{
//Use battery
if(0 <= ppbpi->bBatteryLifePercent && ppbpi->bBatteryLifePercent <= 20)
{
powStatus = POW_VLOW;
}
else if(20 < ppbpi->bBatteryLifePercent && ppbpi->bBatteryLifePercent <= 40)
{
powStatus = POW_LOW;
}
else if(40 < ppbpi->bBatteryLifePercent && ppbpi->bBatteryLifePercent <=60)
{
powStatus = POW_NORMAL;
}
else if(60 < ppbpi->bBatteryLifePercent && ppbpi->bBatteryLifePercent <=80)
{
powStatus = POW_HIGH;
}
else if(80 < ppbpi->bBatteryLifePercent && ppbpi->bBatteryLifePercent <= 100)
{
powStatus = POW_VHIGH;
}
else
{
powStatus = POW_UNKNOW;
}
}
return powStatus;
}
//------------------------------------------------------------------
//Description:
// Thread to get the power status
//----------------------------------------------------------------
DWORD WINAPI CPowerThread::PowerThread(PVOID pArg)
{
m_pInstance->m_bRunning = TRUE;
BYTE pbMsgBuf[sizeof(POWER_BROADCAST) + sizeof(POWER_BROADCAST_POWER_INFO)];
PPOWER_BROADCAST ppb = (PPOWER_BROADCAST) pbMsgBuf;
MSGQUEUEOPTIONS msgopts;
// Create our message queue
memset(&msgopts, 0, sizeof(msgopts));
msgopts.dwSize = sizeof(msgopts);
msgopts.dwFlags = 0;
msgopts.dwMaxMessages = 0;
msgopts.cbMaxMessage = sizeof(pbMsgBuf);
msgopts.bReadAccess = TRUE;
HANDLE rghWaits[1] = { NULL };
rghWaits[0] = CreateMsgQueue(NULL, &msgopts);
if (!rghWaits[0])
{
//erro
return 0x10;
}
HANDLE hReq = NULL;
// Request notifications
hReq = RequestPowerNotifications(rghWaits[0], PBT_POWERINFOCHANGE);
if (!hReq)
{
CloseHandle( rghWaits[ 0 ] );
//erro
return 0x15;
}
while(m_pInstance->m_bExitThread == FALSE)
{
DWORD dwWaitCode = MsgWaitForMultipleObjectsEx( 1, rghWaits, m_pInstance->m_ulWaitTime, QS_ALLINPUT, MWMO_INPUTAVAILABLE );
if ( dwWaitCode == WAIT_OBJECT_0 )
{
DWORD dwSize, dwFlags;
BOOL bReadResult = ReadMsgQueue(rghWaits[0], ppb, sizeof(pbMsgBuf), &dwSize, 0, &dwFlags);
if (bReadResult == TRUE)
{
int iPowPercent;
PowerStatusType powStatus = m_pInstance->GetPowerStatus(ppb,&iPowPercent);
m_pInstance->LockThis();
if(m_pInstance->m_pNotifyPower != NULL)
{
m_pInstance->m_pNotifyPower(powStatus,iPowPercent);
}
m_pInstance->UnLockThis();
}
else
{
// We should never get here
break;
}
}
}
m_pInstance->m_bRunning = FALSE;
return 0;
}
//------------------------------------------------------------------
//Description:
// Get instance
//----------------------------------------------------------------
CPowerThread * CPowerThread::GetInstance()
{
if(m_pInstance == NULL)
{
m_pInstance = new CPowerThread();
}
return m_pInstance;
}
//------------------------------------------------------------------
//Description:
// Set the timeout for the wait thread. It is only for the MsgWaitForMultipleObjectsEx()
//The default value is DEFAULT_TIMEOUT
//----------------------------------------------------------------
void CPowerThread::SetTimeout(ULONG ulTime)
{
m_ulWaitTime = ulTime;
}
//------------------------------------------------------------------
//Description:
// Get the status of thread
//
//Return Values:
// TRUE: The thread is running for capturing the power status.
// FALSE: No thread running.
//----------------------------------------------------------------
BOOL CPowerThread::GetRunStatus()
{
return m_bRunning;
}
//------------------------------------------------------------------
//Description:
// start capturing the power status.If there is thread running,
//it will return FALSE;
//
//------------------------------------------------------------------
BOOL CPowerThread::StartCapture()
{
if(m_bRunning == TRUE)
{
return FALSE;
}
m_bExitThread = FALSE;
//Create the thread for batter sampled
DWORD dwPwrThdID;
HANDLE hdThrd = CreateThread(NULL,0,PowerThread,NULL,0,&dwPwrThdID);
if(hdThrd == NULL)
{
return FALSE;
}
CloseHandle(hdThrd);
return TRUE;
}
//-----------------------------------------------------------------------------
//Description:
// Stop capturing.
//
//--------------------------------------------------------------------------------
void CPowerThread::StopCapture()
{
m_bExitThread = TRUE;
}
//------------------------------------------------------------------
//Description:
// Set the callback function for receive the power status
//------------------------------------------------------------------
void CPowerThread::SetCallbackFunction(void (*pCallbackFunc)(PowerStatusType powStatus, int iBatteryPercent))
{
LockThis();
m_pNotifyPower = pCallbackFunc;
UnLockThis();
}
//------------------------------------------------------------------
//Description:
// Get the callback function
//------------------------------------------------------------------
void CPowerThread::GetCallbackFunction(void (* *pCallbackFunc)(PowerStatusType powStatus, int iBatteryPercent))
{
LockThis();
*pCallbackFunc = m_pNotifyPower;
UnLockThis();
}