Develop Reference

How to bring Android activity to the front without bringing app to front if it is running in background?

I have an app that may run in the background. While it is running, it may bring a certain activity to the front. However, when the app brings the activity to the front, if the app is currently running at background, I do not want Android to bring the app itself to the front, just do it at background. The reason being is I do not want my app to interrupt what the customer is doing at the moment.
The following is my code that launches the activity.
Intent intentLogin = new Intent(getApplicationContext(), LoginActivity.class);
intentLogin.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK|Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intentLogin);
The issue with the above code is every time when it is called, it always bring my app to the front even the app is running at background, that is, annoy my customer.
My question is, is there a way that I can quietly bring the activity to the front? If my app is running in front, thats great --- the customer see the new activity straight away. If my app is running at background, I want to quietly bring the activity to the front when app is running in background, and next time when my customer resume the app, they will see the new activity I brought forward.
How can I do that?
Thank you very much!

如果我没理解错的话：
App background and usual player.
When user logged out , you can clear the user data saved in local and show a notification.And when the notification is clicked, start LoginActivity.
App background and unusual player.
When the notification shows ,the user do not click it instead of run the app.You can check the user data whether existing or not by onResume()in BaseActivity.If not ,start LoginActivity.
App foreground.
clear user data and force to start LoginActivity.
If you don't like the solution above(the best user experence I think),try this:
In onCreate() in the specific Activity ,use moveTaskToBack(true) to hide the intent.But remember to check whether the app is running background or foreground.you can refer to this.

If understand correctly, I suggest this:
User leaves your app, and when user come back to your app you want to show another activity instead of .MainActivity
define another activity as Main and with NoDisplay theme.
<activity
android:name=".MainActivity"
android:theme="#android:style/Theme.NoDisplay">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
then define your normal activities. In MainActivity class define a static variable. for example
public static boolean appRun = false;
onCreate() of SecondActivity change its value to true.
class SecondActivity extends Activity{
#Override
protected void onCreate(Bundle Saved){
super.onCreate(Saved);
MainActivity.appRun = true;
}
}
and onPause set this.finish(); to avoid not resuming to SecondActivity and force to start from MainActivity.
then onCreate() or onResume() of MainActivity check it s value and navigate to another activity.
if(appRun == true){
/*it means user went to SecondActivity and you want to display another*/
startActivity(new Intent(context, NewActivity.class));
}
else{
//this is first time so navigate to SecondActivity
}
Also If you can use Fragments this solution can work for that too.

Exclude current activity from Recent Tasks

My app, running in background, at some point displays activity to purposefully interrupt user's flow. My activity starts a new task, which appears in "Recent Tasks" lists while being in foreground. Is there any way it could be prevented? Setting android:excludeFromRecents does not work - activity is not presented anymore in "Recent Tasks" only after is has been paused.
Manifest looks like:
<activity
android:name="com.example.recenttasks.MainActivity"
android:excludeFromRecents="true">
</activity>
and activity is started this way:
#Override
public void onReceive(Context context, Intent intent) {
Intent i = new Intent(context, MainActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);
}

The key thing you mentioned is
appears in "Recent Tasks" lists while being in foreground
I think you can't change that behavior. I just tested on my app and the same thing happens. If I press the "recent tasks" button while having my activity in the foreground, it appears listed there. The moment I move out of it to another activity or to my phone's main screen, the activity is not listed anymore.
I also tested this on the built-in DeskClock app that comes with recent Android versions and the same behavior is present there when a new alarm is triggered. Note that the AlarmAlertFullscreen activity of that app has the same parameters you mentioned in your question.
I'm not sure you can circumvent this or why you would need to in the first place since the activity is not listed anymore once it loses the focus.

you are defined it in manifest that is enough but it is not coming..
ok..try add this flag also to your Intnet and start the Activity..
intnet.addFlags(Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);

Should the user be able to return to it? (Meaning if it shows and user clicks recents, have they lost their chance to see the hidden activity or should it still be there?)
If they cannot return to it anyway then the best action would be to finish() the activity onPause(). This will mean that as long as you have used android:excludeFromRecents and android:noHistory="true", there will be no item in recents.
If however you do wish to return to the 'interruption' activity (but do not want a recents entry) you could consider still finishing the activity onPause - but also recording a preference flag (something like IS_INTERSTITIAL). Your other activities can then check this preference in onResume and, if it is true, send an Intent to restart the Interstitial instead - To the user it will just appear they are resuming the app in the same state as they left it (interstitial)
Edit: If the screen needs to stay (rather than be re-instantiated) it may be possible to use a DialogFragment, although then you must worry about configuration changes. There is one hack you could try (explained in this answer) -
Set your label empty By using android:label="" your recent task is excluded. however this is a definite hack which may produce inconsistent results (as I haven't tested it to be sure)

More than one instance of activity due to intent

For an App I am developing, I override the back button to make it act like the home button so that the state of the main activity is preserved even when the app is exited. Now, I also send a notification to the user from time to time using a service. When this notification is pressed I want to open the main activity again. I noticed though that this creates a second instance of the app, which creates major problems. I am trying to make the main activity go to the front again, without calling oncreate again like so:
Intent to launch main activity again:
Intent notificationIntent = new Intent(this, MainActivity.class);
notificationIntent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
This doesn't work though. I still end up with two instances of my main activity. Does anybody know how to fix this?
By the way, I already have android:launchMode="singleInstance" in my manifest.

There's a way to force the OS to create only one instance of an activity and thats using the tag launchMode in the Manifest as shown below:
<activity android:name="YourActivity"
android:launchMode="singleInstance"/>
Hope this Helps...
Regards

Try adding this flag to the intent .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP), works for me.

Continuing the same activity when user clicks on Notification

i am making an application in which Broadcast listener is starting an activity and notification is displayed.
when a user clicks on home button it goes to the home screen.
But if user clicks on Notification icon then activity state is lost :( .
Please help me how to continue with my activity when user clicks on notification.

I don't display a notification if the application that is doing the notifying is in the foreground; I just update the UI of the activity and let it be self-evident.

Try this:
Intent resultIntent = this.getIntent();
It gets the started intent from main activity. Worked for me.

I suggest using an alert dialog for notifications link here. This will keep your notification on the same screen and in the same activity.
If you want to keep any information when you press home you may use android storage for that and here is the link for that. Storage will be able to hold data that you need from other activity classes.
I hope this helps you.

When building your Intent for the PendingIntent you send with the notification, add the flag Intent.FLAG_ACTIVITY_NEW_TASK.
If the activity is already on the history stack, it will be resumed and a call to onNewIntent() will be triggered. If it's not, the activity will be started with a blank slate.

Try this
Intent.FLAG_ACTIVITY_TASK_ON_HOME

android - launchMode=singleTask and Notifications?

I know there's been a few posts for what I'm about to ask but I can't find any with the right answer.
From my understanding, if your main activity's (let's call it A) launchMode is set to singleTask, and A has initiated activity B then a click to the home button will destroy the history stack and re-launching the application will take you back to A and not B.
I have launchMode set to singleTask because I have a persistent notification and I don't want to have multiple instances of the main activity to appear whenever the user clicks on the notification.
Is there something I'm missing that would allow me to cater for both?
So I'm asking if there's a way I can ensure that whenever the user wishes to launch the app, from the notification or not, to take him back to the last (current) activity.
If I change launchMode to singleTop it works but I get multiple instances of the main activity whenever I launch it.
Thanks
Andreas

Have you tried setting launchMode to singleTop to all the activities in your app?? Because what i get from your query is that the main activity isn't singleTop, so that might lead to another instance of the main activity being called once the main activity is launched from the activity that was launched from the notification activity.
Or you can specify the launchMode as an attribute to the application tag itself in the manifest.

I use the following code to avoid multiple instances of the activity
Intent intent=new Intent(this,RICO.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP|Intent.FLAG_ACTIVITY_SINGLE_TOP);
PendingIntent contentIntent = PendingIntent.getActivity(this, 0, intent, 0);
Changing manifest doesn't look appropriate to me

I'm having issues with both the approches.
The notification works flawless only in this condition:
- using the back button in the main activity (with the history containing only the that activity)
- not using the Home button
- not using the notification IF the activity you are calling is on top and active
In any other case, the notification cannot anymore call on the foreground the activity by using "new Intent(...)"

I've found the alchemical combination of manifest options and intent's flags for getting what I needed:
Intent intent= new Intent(this, YaampActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
using these options
android:launchMode="singleTask"
android:taskAffinity=""
android:excludeFromRecents="true"
inside the element.
Now I've a notification which spawns the main activity (if that activity is not already in the foreground) and its behavior is correct even if the activity is "closed" by pressing the home button and/or the back one.