wince电源管理（Wince power management）.docVIP

wince电源管理（Wince power management） Power management The Windows CE is a typical battery powered system. This makes the correct operating system critical, and most of the time the application does not have to pay attention to the power loss of the Windows CE device, but at some point you may be aware of these losses. When the user closes a battery of Windows CE equipment, power supply system will not shut down PC power, in fact, only the system is suspended (translators note: here is some PocketPC to turn off the power on the removal of SIM card position, pull out the SIM card really power off. However, at present, including Smartphone, because the hardware equipment, such as CPU cannot enter a low power, so in order to save power, need to close the application processor and most of the equipment supply, then need to wake up, wake up again through the timer or wireless module. So its not absolute that you dont turn off the power When the user opens the device power, the device does not restart like PC, but is awakened and returned to the same state as before the system was suspended. This leads to an application that will run as if it were pending before waking up. In fact, the application simply doesnt know it is pending unless it explicitly requests it to be notified when the system hangs up. From an application point of view, there are three ways of power management, querying the power status, changing the power status, and preventing the power status from changing. Query power status To query the current power status of the system, you must call DWORD GetSystemPowerStatusEx2 (PSYSTEM_POWER_STATUS_EX2, pSystemPowerStatusEx2, DWORD, dwLen, BOOL, fUpdate); The function takes three parameters: a pointer to a SYSTEM_POWER_ STATUS_EX2 structure pointer, the length of the structure, and a Boolean value that tells whether the operating system should check the battery driven to get the final information or directly back to the battery in the cache information. About every