private void OnPowerNotify(object sender, PowerManager.PowerEventArgs e)
{
PowerManager.PowerInfo powerInfo = e.PowerInfo;
PrintLn(
powerInfo.Message.ToString()
+ " " + powerInfo.Flags.ToString("X")
+ " " + GetSerialPortList()
);
if (PowerManager.MessageTypes.Transition == powerInfo.Message)
{
// Ideally, we'd switch on the symbolic Flags enums,
// but they don't cover all the observed values.
switch ((uint)powerInfo.Flags)
{
case 0x00400000:
// 0x00400000 is the lightest stage of power management,
// probably corresponding to backlight off. It occurs
// even when USB doesn't get powered down.
//
// However, we should react to it because it is always
// the first thing our app sees when coming out of suspend.
// Sometimes, waking is very slow, and the user will be confused
// unless we trigger some feedback at the time of this first event.
PrintStatus("Power interruption detected. Recalculating...", true);
CloseReader();
break;
case 0x00200000:
// 0x00200000 == SystemPowerStates.Suspend
PrintStatus("Suspend detected", true);
SuspendTripped = true;
TransitionsSinceSuspend = 0;
break;
case 0x10000000:
// 0x00100000 == SystemPowerStates.Idle
// Not sure why Idle is always observed *after* Suspend.
// I thought Suspend was the deeper sleep state; e.g.,
// http://nicolasbesson.blogspot.com/2008/04/power-management-under-window-ce-part.html
break;
case 0x12010000:
// 0x12010000 occurs when subsystems are powering up
// ActiveSync is one of these subsystems, so we can't do
// too much with this event, or we'll get false positives.
//
// The first 1201000 after Resume tends to correlate with the
// FTDI serial port being back up, but not sure if order is guaranteed.
//
// There are usually 2 1201000 transitions after waking from resume.
// There is a third one, several second later, when ActiveSync enables.
TransitionsSinceSuspend += 1;
PrintStatus("Detected " + TransitionsSinceSuspend + " transitions since suspend", true);
if (SuspendTripped && (2 <= TransitionsSinceSuspend))
{
if (null != rdr)
{
PrintStatus("Cleaning up reader connection...", true);
CloseReader();
PrintStatus("Reopening reader...", true);
OpenReader();
}
SuspendTripped = false;
}
break;
}
}
//switch (powerInfo.Message)
//{
// case PowerManager.MessageTypes.Resume:
// PrintLn("Resume Detected");
// NeedResumeRecovery = true;
// break;
// case PowerManager.MessageTypes.Transition:
// if (NeedResumeRecovery)
// {
// // Reader's serial port becomes invalid during suspend
// // Restore it here (if it was already open before suspend)
// if (null != rdr)
// {
// PrintStatus("Reconnecting...");
// // See how much we can get away with
// try
// {
// GetVersion();
// }
// catch (Exception ex)
// {
// // We can catch the serial write exception here, but I'm not sure why.
// // Isn't it supposed to happen in the GUI thread due to Invoke?
// PrintLn("Caught Exception trying to use broken reader: " + ex.ToString());
// }
// // Clean up old reader (to prevent SerialReader.Dispose method
// // from trying to talk to it and throwing an exception somewhere
// // we can't handle it.
// PrintStatus("Cleaning up old reader...");
// PrintLn("Cleaning up old reader...");
// CloseReader();
// PrintStatus("Reopening reader...");
// PrintLn("Reopening reader...");
// OpenReader();
// PrintStatus("Connected");
// }
// NeedResumeRecovery = false;
// }
// break;
//}
}
private void InitializePowerManager()
{
// Create a new instance of the PowerManager class
pwrMngr = new PowerManager();
// Hook up the Power notify event. This event would not be activated
// until EnableNotifications is called.
pwrMngr.PowerNotify += new PowerManager.PowerEventHandler(OnPowerNotify);
// Enable power notifications. This will cause a thread to start
// that will fire the PowerNotify event when any power notification
// is received.
pwrMngr.EnableNotifications();
//// Get the current power state.
//StringBuilder systemStateName = new StringBuilder(20);
//PowerManager.SystemPowerStates systemState;
//int nError = pwrMngr.GetSystemPowerState(systemStateName, out systemState);
}