Android Activity Not Showing When Screen is Woken Up and Lock Screen Not Disabling

问题

I have a BroadcastReceiver that starts an Activity. If the Activity is started while the screen is on, it displays and everything is fine. However, on ICS and JB devices (I haven't tested GB or HC but the issue doesn't exist with Froyo) if the Activity is started while the screen is off, the lockscreen is not disabled, and the activity is not shown when the phone is unlocked (either through unlocking it manually or with the code I put in for post Froyo devices).

Why, on at least ICS and JB devices, does the lockscreen not get disabled without the mentioned code below, and why doesn't the activity show if the screen was off when the Activity was started?

Here's the code:

In the BroadcastReceiver:

Intent alarmAlert = new Intent(context, AlarmGoneOffActivity.class);
alarmAlert.putExtra(MyAlarmManager.ALARM_NUM_ID, alarm.ID);
alarmAlert.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | 
                    Intent.FLAG_ACTIVITY_NO_USER_ACTION);
context.startActivity(alarmAlert);

In AlarmGoneOffActivity.onCreate():

setContentView(R.layout.alarm_gone_off);

final Window win = getWindow();
win.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN | 
             WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD | 
             WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED | 
             WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON,
             WindowManager.LayoutParams.FLAG_FULLSCREEN | 
             WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD | 
             WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED | 
             WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
}

//so far all of my post froyo devices (ICS and JB no more GB)
// don't bypass the lockscreen unless we use this
if(Build.VERSION.SDK_INT > Build.VERSION_CODES.FROYO) {
    KeyguardManager  myKeyGuard = 
                    (KeyguardManager)getSystemService(Context.KEYGUARD_SERVICE);
    KeyguardLock myLock = myKeyGuard.newKeyguardLock("ShabbosAlarm");
    myLock.disableKeyguard();
}

Edit: I would really prefer not to use KeyguardLock.disableKeyguard() because it causes the keyguard to become disabled until KeyguardLock.reenableKeyguard() which is inconvenient. Any solutions?

Edit2: I can now confirm that the issue only exists on ICS and above. Was something changed that prevents the keyguard from being disabled? And even if there was, why is my Activity not showing when the screen is manually unlocked?

回答1:

Here is the base implementation I used to achieve this. It's working for my users from 2.3-4.3. You can build on it from here I'm sure. I created this very short-lived Activity, just to handle this event - You can use it as a helper Class if needs be:

import android.app.Activity;
import android.os.Bundle;
import android.view.WindowManager;

public class BlankActivity extends Activity {

    @Override
    public void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        getWindow().setFlags(
                WindowManager.LayoutParams.FLAG_FULLSCREEN | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
                        | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON,
                WindowManager.LayoutParams.FLAG_FULLSCREEN | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
                        | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);


        // Your code here - Or if it doesn't trigger, see below
    }

    @Override
    public void onAttachedToWindow() {

        // You may need to execute your code here

    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);

        if (newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE) {

        } else if (newConfig.orientation == Configuration.ORIENTATION_PORTRAIT) {

        }
    }

    @Override
    public void onPause() {
        super.onPause();

        finish();
    }
}

And in the Manifest:

    <activity
        android:name="com.your.package.BlankActivity"
        android:clearTaskOnLaunch="true"
        android:configChanges="keyboardHidden|orientation|screenSize"
        android:excludeFromRecents="true"
        android:launchMode="singleInstance"
        android:noHistory="true"
        android:theme="@android:style/Theme.Translucent.NoTitleBar.Fullscreen" >
    </activity>

Contrary to other related posts, the Translucent theme did not cause an issue, neither was there a need for a layout to be added to the Activity.

Hope it works for you too.

来源：https://stackoverflow.com/questions/12979709/android-activity-not-showing-when-screen-is-woken-up-and-lock-screen-not-disabli

标签

android

android-activity

android-screen

android-windowmanager