Starting activity from service on lock screen turn

问题:

I'm trying to start an activity from a service I had already acquired the lock for as follows:

Intent i = new Intent(context, MyActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_NO_USER_ACTION);
startActivity(i);

The activity manifest is declared as follows:

<activity
        android:name=".MyActivity"
        android:configChanges="orientation|screenSize|keyboardHidden|keyboard|navigation"
        android:excludeFromRecents="true"
        android:launchMode="singleInstance"
        android:screenOrientation="nosensor"
        android:showOnLockScreen="true"
        android:taskAffinity=""
        android:theme="@style/MyTheme" />

And finally, on onCreate() or on onAttachedToWindow() (I tried on both), I add the following flags:

final Window win = getWindow();
win.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
            | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);
win.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
            | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON
            | WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON);

The problem is that the first time I call startActivity() from my service, the screen turns on but the activity itself does not show up. It shows the lock screen instead. Every subsequent call of startActivity() works properly but I can't find a reason for this odd behavior.

I tried already suggestions to get a full wakelock instead of partial, change the flags and values in the manifest according to the following SO answers:

• Android Activity Not Showing When Screen is Woken Up and Lock Screen Not Disabling
• how to unlock the screen when BroadcastReceiver is called?
• Programmatically turn screen on in android
• Android Galaxy S4 -- Activity that is visible over lock screen

Note that my theme is not a dialog but a fullscreen activity.

Any other ideas?

回答1:

I'm facing the same problem, after a lot of searching here and google, found this which unlocked the screen and popped my activity but it only works for me when the app is running (foreground/background).

import android.view.Window;
import android.view.WindowManager.LayoutParams;


Window window = this.getWindow();
window.addFlags(LayoutParams.FLAG_DISMISS_KEYGUARD);
window.addFlags(LayoutParams.FLAG_SHOW_WHEN_LOCKED);
window.addFlags(LayoutParams.FLAG_TURN_SCREEN_ON);

i'm trying to start an activty when app is closed... (using broadcast receiver)

in the docs (for example here) and most of the answers on SO the flags are added this way:

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

but when i tried the way it is like in the example it unlocked the screen instead of just turning on the screen.

hope this help . it still didn't solve my problem completely.

EDIT:

found this post which solved my problem.

there is a comment there on NOT using a dialog theme which solved it for me

回答2:

Step 1: Add below code in your activity before

setContentView(R.layout.activity_about_us);

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

Step 2: Lock your mobile than you will see activity in which you have added this code.

You can implement this if you want to open particular screen by notification occurrence like skype call.

回答3:

Since my application already includes a Service, this is what I do: if the screen is locked, I register a broadcast receiver (a bit simpler than this one, since it reacts only on unlocking) that starts the Activity as soon as the screen gets unlocked.