Android: Clear Activity History

Question

I've faced with one problem - clearing activity history. I have the following consequence where my problem appears:

A(SplashScreen)->B(GuestScreen)->C(Screen for signed users)->Press Home Button->A->B->Press Back Button->C->Press Back BUtton->B->Press Back Button->exit from the app.

I tried different ways to solve it and found only one quite strange solution throughout setting almost all activities to singleInstance and setting all intent flags to CLEAR_TOP and NEW_TASK but all activities are presenting some strange(not as normally, I mean, firstly, there appears empty black screen with actionBar and after ~1 second appears my real layout) and with a bit delay as I already said. I didn't like this solution in spite of that everything closes correctly and in correct consequences. Now, I'm trying to get it work normally without this delay and strange black screen on a moment. I tried to play with intent flags like CLEAR_TASK, CLEAR_TOP too. Tried to use clearTaskOnLaunh for root activity and finishOnLaunch in manifest file for others where it`s necessary, doesn't help. How to fix it?

EDIT:

Trying set clearTaskOnLaunch to A again. I see next log when start app first time(A has already called B without any flags):

  Main stack:
    TaskRecord{42610648 #869 A }
    Intent { flg=0x10000000 cmp=/.activities.SplashActivity }
      Hist #4: ActivityRecord{413cf8f8 /.activities.GuestActivity}
        Intent { cmp=/.activities.GuestActivity }
        ProcessRecord{414fdf60 15651:/10103}

// Guest Activity(B) calls UserActivity(C):

    Intent { flg=0x10000000 cmp=/.activities.SplashActivity }
  Hist #3: ActivityRecord{415c86f0 /.activities.UserActivity}
    Intent { cmp=/.activities.UserActivity }
    ProcessRecord{414fdf60 15651:/10103}

//Press Home Button and launch app again(A has called B):

    TaskRecord{42610648 #869 A cashongo.app.peachy}
Intent { flg=0x10000000 cmp=c/.activities.SplashActivity }
  Hist #5: ActivityRecord{42127398/.activities.GuestActivity}
    Intent { cmp=/.activities.GuestActivity }
    ProcessRecord{414fdf60 15651:/10103}
  Hist #4: ActivityRecord{415c86f0 /.activities.UserActivity}
    Intent { cmp=/.activities.UserActivity }
    ProcessRecord{414fdf60 15651:/10103}

The same problem again, last activity in history. If I press back button I`ll get UserActivity.

Answer 1

I didn't understand your question 100%

I think you are facing problem with activity stack and CLEAR_TOP

so use startActivityForResult instead of startActivity

Answer 2

It seems I have managed to fix it but it is still a bit strange. I have set launchMode=singleInstance to A and B activities. And call any activities without any flags. No black screen with 1 second delay between activity`s calling. A bit strange solution because google not recommend use singleInstance or singleTask for general situations, I think it's general. If someone will find a better solution you are welcome.

UPDATE: One more very important thing when build and start apk via IDE. Some kind of IDE start app wrongly see this post. Due to it stack behaviour can be changed.

Answer 3

The way we fixed it is taking a static boolean variable in the immediate first activity .Say your first activity is A,In A declare variable as below

public static boolean closeAllActivities=false;

Then in rest of all activities place the below code in onResume()

protected void onResume() {
super.onResume();
if(A.closeAllActivities)
{       
    finish();   
}
else
{
    // TODO your requirement inside onResume
}
      }

And wherever u would like to exit the application set as

A.closeAllActivities=true;//It exits all the activities one after other.