I have a problem like the above question. I want to know when all views will load on MainActivity and after loading I will start running Service. Is there any way? Thank you.
You can start the service in onResume() of your MainActivity. Based on the documentation:
This is where the lifecycle components can enable any functionality
that needs to run while the component is visible and in the
foreground, such as starting a camera preview.
If lifecycle of your service is tied to that of Activity, then remember to call stopService() in onPause(). Otherwise, you have to do some condition checking beforestating the Service to avoid calling startService multiple times.
I have one service and two activities. I from one Activity go to another, and in the onStop method, do unbindService.
When I came in the second Activivity the service destroyed.
When the second activity calls the bindservice, a new service is created.
How to make so that the service is not destroyed?
If you want that service should not stop when migrating to next activtiy,then you should use IntentService instead of Service.
InetntService don't have any UI,so it will contiously runs in the background without user interaction and when it finishes then you have to store its data somewhere (or you can use the broadcast reciver )and populate that data in the next actvity if you need.
Let's assume I have 2 activities: Activity 1, Activity 2. I am starting Activity 2 from Activity 1. Activity 2 - is activity with image and progress bar to display the progress of executing some background task in it which is started in service.
When I try to press hardware Back button from Activity 2 it brings me back to Activity 1, so I can start Activity 2 again even if there is service still running.
So the question is such: How can I prevent such behaviour. I need to start Activity 2 only 1 time and not exit from it while the work is not finished?? And another case is that I can stop my application from Task manager, but service will be working and after that I can run application again - with new service, while old will be still running? What mechanisms are there to prevent such behaviour? Thanks.
You can bind to a local service from your Activity class when it is starting up. Once bound, your Activity can call any public methods declared by that service. This would allow your Activity to bind to the service, then check to see if the service is currently doing any work. You might make a method like isRunning() or similar. If the service is not currently doing any work, you might want to start a new job. If it is already executing some task, you could then display the current progress of that task.
You should read the Local Service Sample article on the Android developer site to get an idea how to do this.
I have a toggle button in my main activity. I want a service to start when the toggle button is on and stop when it is off. The activity may be closed at any time. I want the activity to 'remember' the service it had started before the activity was closed and the activity should be able to close this service it had started on its previous run.
What should I do?
Read this Service first, then use these guys to control it: startService() and stopService(). About remember, you can use static variable to check the status of service, and change it on onCreate and onDestroy of your service, it's like one of the solutions.
I have a Service which tracks the location of the user. Currently, the Service boots when the application starts and stops when the application terminates. Unfortunately, if users keep the application in the background, the Service never stops and drains battery.
I would like the Service to stop when my application is not in the foreground. I was hoping the Application class would let me Override onPause and onResume handlers, but it does not have them. Is there another way I can accomplish this?
I haven't tested this yet, but it looks like if you use Context#bindService() (instead of Context#startService()), the service should stop when no more activities are bound to it. (see Service lifecycle).
Then use onPause()/onResume() in each activity to bind/unbind from the service.
Alternatively, you could add a pair of methods on your service which tell it to start/stop listening for location updates and call it from each activity's onResume()/onPause(). The service would still be running, but the location updates wouldn't be draining the battery.
Reading all the above answers I would suggest Simply add a boolean global flag for each activity & put it in your onResume & onPause & also while launching an Activity Something like this
public void onPause()
{
super.onPause();
activity1IsResumed = true;
}
&same for onResume
& similarly when launching a new Activity
startActivityForResult(myintent ,0);
activity2IsResumed = true;
activity1IsResumed = false;
then in your Service simply check
if(activity1IsResumed || activity2IsResumed || activity3IsResumed)
{
//your logic
}
else
{
//another logic
//or dont run location tracker
}
& you are done!
You should override the onPause and onResume methods on your Activity. If you have multiple activities you may want to have a common base class for them and put the start/stop logic into the base class.
I have not tried this approach but I think you can override the home key of android device by using KeyEvent.KEYCODE_HOME and you can use stopService(Intent) to stop your service and when again application resumes, you can write startService(Intent) in the onResume() method of your Activity.
This way I think your service will only stop when user explicitly presses home button to take application in the background and not when he switches from one activity to another.
What I would suggest is overriding the onPause/onReume methods as others have said. Without knowing more about the flow of your application and interactions between Activities, I can't give much more information beyond guesswork.
If your Activities are persistent, however, my recommendation would be to utilize the Intents better when switching between Activities.
For instance, each Activity should have a boolean "transition" flag. So, when you move from one Activity to the next, you set up an Intent extra:
intent.putExtra("transition",true);
Followed in the receiving Activity by: (in onCreate)
intent.getBooleanExtra("transition",false);
This way, for each Activity that launches, you can know whether it has come from another Activity, or if it has been launched from a home screen launcher. Thus, if it gets a true transition, then onPause should NOT stop the service--that means you will be returning to the previous Activity after it returns. If it receives no "transition" extra, or a false transition, then you can safely assume there is no Activity underneath it waiting to take over for the current one.
On the first Activity, you will simply need to stop the service if you are switching to another Activity, which you should be able to figure out programmatically if one Activity is started from another.
It sounds like the real problem is how to only stop the service when you go to an activity that isn't one of your own? One way would be to in your onPause method to stop the activity. Do this for all your activities. Then override your startActivity method. And in here do a conditional test to confirm that you are purposefully navigating to one of your own. If your are set a flag to true.
Now go back to your on pause overridden method. And only stop your service if the flag is not equal to true. Set the flag to false.
All events that navigate away will close your service. Navigating to your own will leave it intact.
Do the overriding in a base class that all your activities extend.
Writeen in my andolroid. Will post ezaple later.
Try using the Bound Services technique to accomplish this.
Bound Services | Android Developers
You can use bound services in a way such that the service will stop when no activities are bound to it. This way, when the app is not in the foreground, the service will not be running. When the user brings the app back to the foreground, the Activity will bind to the service and the service will resume.
Create methods registerActivity() and unRegisterActivity() in your Application object and implement first method in all you acts onResume() and second in acts onPause().
First method add activity to List<Activity> instance in your app object, unRegisterActivity() checks size of list in every call if==0 stopService();.