尝试戳我的Android并以编程方式打开屏幕

Question

I am building an alarm kind of application for Android.

I set a certain timer to run and then fire after a certain time interval (after the user presses a button) which I call in the onCreate method.

final int interval = 20000; // 20 Second
Handler handler = new Handler();
Runnable runnable = new Runnable(){
      public void run() {
            Toast.makeText(getApplicationContext(), "Timer to Wake",Toast.LENGTH_SHORT).show();
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON|WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
      }
};

handler.postAtTime(runnable, System.currentTimeMillis()+interval);
handler.postDelayed(runnable, interval);

I've also disabled the keyboard in the onCreate method with:

getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD|
    WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);

In the Android developer docs, it says:

Window flag: when set as a window is being added or made visible, once the window has been shown then the system will the power manager's user activity (as if the user had woken up the device) to turn the screen on.

Now after I fire the timer with a press of the button, I immediately turn off the screen. After waiting 20 second though, the screen isn't poked and the device doesn't awaken. What could be the issue here? When I do turn on the screen though with the power button after waiting another 20 seconds, I do find that the keyboard is disabled. Also the screen is perpetually awake when I do leave the screen on. So I know the flags are working. I just need it to "wake" up when the timer fires!

Answer 1

you should use AlarmManager and PendingIntent

AlarmManager am=(AlarmManager)getApplicationContext getSystemService(Context.ALARM_SERVICE);
Intent i = new Intent(context, SampleActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, intent, 0);
am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(),(9 * 1000), pendingIntent);

Answer 2

Turns out, I had to properly group the right methods in the correct area. I had previously split the FLAG_DISMISS_KEYGUARD and FLAG_TURN_SCREEN_ON in different areas.

To successfully turn on the screen:

public void run() {
    Toast.makeText(getApplicationContext(), "Timer to Wake", Toast.LENGTH_SHORT).show();
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
}