Setting launchMode="singleTask" vs setting activity launchMode="singleTop"

android android-activity android-manifest android-navigation
NSouth picture NSouth · Sep 10, 2014 · Viewed 48.9k times · Source

I have an app that is very hierarchical (activities are similar to League > Team > Position > Player) and so I've made each activity singleTop in order to keep navigation sensible and to prevent duplicate instances.

Now I'm making my second app and I've seen it suggested to declare my application to be singleTask to prevent duplicate instances. Could someone help explain the advantages of each approach?

My new app is just an activity with 3 fragments and then I'll probably add a settings activity and maybe a FAQ.

EDIT: I just realized that singleTask is NOT preventing duplicate instances of my app, as I had thought. Now looking for the right way to handle this...

Answer

CChi picture CChi · Sep 10, 2014

I think your definition of singleTop and singleTask is a little off. SingleTop could produce a duplicate instance. Lets use your example, League > Team > Position > Player. If there is a button in the player screen that will take you to the league screen, it will become League > Team > Position > Player > League.

Whereas singleTask guarantees that only one instance of the activity can exist.

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