java - Android: OutOfMemory error and the backstack

Question

the following sheet represents the working flow in the application this question is about.

I ran into problems with OutOfMemory Errors, mostly because users were able to switch from activity B to activity D multiple times (They are showing different content for every attempt), without the previous activity being destroyed. This led into a very large backstack resulting in an OutOfMemory error.

To avoid this, I followed the recommendation to add parent activites to the manifest and create new backstacks with the TaskStackBuilder class:

void openDFromB()
{
    Intent i = new Intent(this, ActivityD.class);
    TaskStackBuilder.create(this)
        .addParentStack(ActivityD.class)
        .addNextIntent(i)
        .startActivities();
}

If a user now switches from activity B to D, MainMenu, A and B are destroyed and a new Backstack (MainMenu, C, D) is created. This solves my memory problems for api level greater 10, but unfortunately the TaskStackBuilder does not create backstacks for devices pre api 11.

Any idea what to do in order to avoid users stacking infinite amounts of activities prior api 11? Is this even possible or should I try to free as many resources as possible in onPause to gain a maximum amount of stacked activities before OoM?

thanks in advance!

Answer 1

Try this-

Intent intent = new Intent(getApplicationContext(),yourActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);

Another solution is-

Setting android:noHistory="true" on the activity in your manifest file will remove an activity from the stack whenever it is navigated away from.

But the most appropriate way is to call finish() method whenever you start new activity like in the following sample code-

Intent intent = new Intent(this, yourActivity.class);
startActivity(intent);
finish();

You can also create custom Broadcast receiver and register it in every activity which can be fired on event of your choice. For more help you can check this link.