I have an app that could be launched by a user or by the system (based on its main activity intent). So, in some cases there might be two instances of the app running at the same time.
Is there a way to limit the app to a single instance?
Thanks.
Add android:launchMode= "singleInstance" to your activity.
Hope it helps.
Related
What are the ways to starts a android activity in different process .
one I know is Adding in the manifest
android:process=":YourProcessName">
is there any other method while starting Activity using intent etc?
is there any other method while starting Activity using intent etc?
No, sorry.
Note that running activities in separate processes is usually unnecessary.
I write application on android which will be runnig all the time on background. There will be only one starting view on first run. I want to user run instance of my app only once, and cant run any other instance at the time. When he try to run this app when one instance of this app is running already he sould see some warning notification. My problem is I dont know how to prevent user from multiple start of my app. Is this possible? If it is possible, how can I do it? Thanks for any help.
For background processing I would recommend to consider Services. Services are created to deal with longterm background tasks. I think foreground service(like Skype) may be interesting for you.
As Phil suggested you can you launch mode to control your activity behaviour. Consider using launchMode = "singleTop"
You need to pick a launchmode that will best fit your needs (probably singleInstance or singleTask). As for popping a notification, you can handle that in onCreate or onResume, however it doesn't have anything to do directly with how many instances are running.
I have a UI flow that has activities launched via intents in separate applications. For example, the first screen would be an activity in application B, launched from my application, the second from application C etc.
To control this flow I was thinking of using a service. Is this the correct approach? Or would it be better to use light weight activities with no UI to launch the external activities?
Not sure to understand correctly what you are trying to achieve, but
I think that startActivityForResult may be useful to you.
While application will be started, I want to launch one activity if some condition is satisfied else want to launch another activity. How to do this?
Start the one, and in onCreate() check the condition. If it is not satisfied start your another activity.
you must do it handling all conditions in an initial activity, which will check your rules and start the other activitys.
I don't know much about your particular use case, but if your application has to launch different activities depending on the task it is supposed to do, you should consider having appropriate intent-filters for each, and sending an Intent that's in accordance to the intended effect. That will make the correct activity be launched depending on the Intent, which is one of the great features of Android.
But of course, if you can only decide which activity is best once you launch your app, this approach doesn't work, and you have to launch an initial activity to decide which one to call next.
If it's highly likely that one activity will be launched, you might consider launching it as the first activity and then testing whether you need to launch another instead. That's probably cleaner than having a separate activity just to make the decision about which other activity to launch.
Bruno Oliveira, Developer Programs Engineer, Google
I need to guarantee that my Android application won't be launched twice. How to do it? I mean in ideal I would need in case of second launch just switch to primary copy.
Consider using android:launchMode More on that here
According to the Android activity lifecycle, it shouldn't be possible to start a second copy on an activity. If it isn't terminated, it will resume the running instance.
That is the normal behavior of app launching. You don't need to do anything special. (And definitely do not at all use the android:launchMode="singleInstance" option. That is a very special behavior that is probably not what you want.)