问题
I have 3 activities A, B and C. A leads to B which leads to C. I would like to be able to move back and forth between A and B but I want to finish both A and B once C gets started. I understand how to close B when starting C via the intent but how do I also close A when C gets started?
回答1:
In your onCreate()
method assign a static instance to a variable to create a Singleton:
public static ActivityA instance = null;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
instance = this;
}
@Override
public void finish() {
super.finish();
instance = null;
}
then in C:
public void onCreate(Bundle savedInstanceState) {
if(ActivityA.instance != null) {
try {
ActivityA.instance.finish();
} catch (Exception e) {}
}
}
(Repeat above code for B as well as A)
I would say this is NOT elegant and is bound to introduce strange lifecycle bugs.
It would be better if you could tweak your requirement - if you can't you could perhaps use a single Activity and change A, B and C into Fragments
?
I would have suggested a Broadcast but as I understand it you can't have instance level broadcast receivers on "non resumed" Activities.
Using a Service
to bind to the Activities seems like overkill - but you might want to consider that if the above doesn't work.
Good luck!
回答2:
((Activity)context_of_another_activity).finish();
回答3:
When you start C from B, do it in this way:
Intent intent = new Intent(this, A.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
Now, C starts, but A and B are gone.
However, I think it is better if you can rethink your design such that C does not depend on A being finished or not.
来源:https://stackoverflow.com/questions/15792014/finish-activity-from-another-activity