CODEWITHSUNDEEP
androidback-stackactivity-stack
azzits
azzits

Reputation: 705

How to find back stack activities in an android application?

I have an application with activities back stack A -> B -> C -> D -> E. Now at activity E, I want to know the back stack activities that I navigated from. How do I find this??

Upvotes: 21

Views: 34904

Answers (8)

Amit_dash_234
Amit_dash_234

Reputation: 101

The most obvious answer would be keeping a reference somewhere safe like in a utility class as a static variables in certain order, like in a list, but this can be dangerous as it can lead to a memory leak, so make sure you manually handle it and dispose them when needed.

Upvotes: 0

Karan Bhandari
Karan Bhandari

Reputation: 506

I recommend you to utilize startActivityForResult instead of startActivity, then in order to retrieve the origin/source activity- call getCallingActivity().getClassName().

How will A know it came from home? Use getIntent() its

getAction() -> android.intent.action.MAIN

and

getCategories() -> android.intent.category.LAUNCHER

Upvotes: 1

android developer
android developer

Reputation: 116332

I think you can do it by listening to the changes of the activities, via this API of registerActivityLifecycleCallbacks :

https://developer.android.com/reference/android/app/Application.html#registerActivityLifecycleCallbacks(android.app.Application.ActivityLifecycleCallbacks)

https://developer.android.com/reference/android/app/Application.ActivityLifecycleCallbacks.html

This will help you to add to a stack of your own classes, and see the full state as you wish.

Upvotes: 1

Gianluca P.
Gianluca P.

Reputation: 1551

As getRunningTasks(..) has been deprecated or if you don't want to add special permissions to your app here is an alternative solution if all activities are yours: you can mark an identifier (not the activity itself is it may be in need to be garbage collected) in a singleton Stack, LinkedList or LinkedHashSet: in onPause() add the identifier to the stack and remove it in onResume().

You can check the contents of that stacks to know if there is any activity and the sequence they have been created.

You can clean up your code and forget to do that manually if all your activities derive from a common base activity for your app.

Upvotes: 1

suresh
suresh

Reputation: 123

You can use "adb shell dumpsys activity activities" command

for reference http://www.onsandroid.com/2015/01/find-back-stack-activities-in-android.html

Upvotes: 4

Mikonos
Mikonos

Reputation: 159

actually, you can get the task id from the runningtaskinfo using getRunningTasks and then, get the recenttaskinfo using getRecentTasks by compare the task id. now you can restart that activity using startactivity, with the baseintent in the recenttaskinfo.

Upvotes: 0

Rajdeep Dua
Rajdeep Dua

Reputation: 11230

The code below can be used to extract all the tasks and the top activity within each task in the back stack

ActivityManager m = (ActivityManager) ctx.getSystemService( ctx.ACTIVITY_SERVICE );
List<RunningTaskInfo> runningTaskInfoList =  m.getRunningTasks(10);
Iterator<RunningTaskInfo> itr = runningTaskInfoList.iterator();
while(itr.hasNext()){
    RunningTaskInfo runningTaskInfo = (RunningTaskInfo)itr.next();
    int id = runningTaskInfo.id;
    CharSequence desc= runningTaskInfo.description;
    int numOfActivities = runningTaskInfo.numActivities;
    String topActivity = runningTaskInfo.topActivity.getShortClassName();
}

Upvotes: 6

Quentin DOMMERC
Quentin DOMMERC

Reputation: 876

I'm not sure i get it well...You want to go back to the previous activity ? If so, finish the current activity you'll get back to the previous one.

Upvotes: 0

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