Clear the entire history stack and start a new activity on Android

Question

Is it possible to start an activity on the stack  clearing the entire history before it   The situation  I have an activity stack that either goes A- B- C or B- C  screen A selects the users token  but many users only have a single token     In screen C the user may take an action which makes screen B invalid  so the application wants to take them to screen A  regardless of whether it is already in the stack  Screen A should then be the only item on the stack in my application   Notes  There are many other similar questions  but I haven t found anything that answers this exact question  I tried calling getParent   finish   - this always results in a null pointer exception  FLAG ACTIVITY CLEAR TOP only works if the activity is already on the stack

User · Answer

With Android s Newer Version    API 16 use finishAffinity    approach is suitable for    API 16   Intent mIntent   new Intent mContext MainActivity class   finishAffinity    startActivity mIntent      Its is same as starting new Activity  and clear all stack   OR Restart to MainActivity FirstActivity

User · Answer

I spent a few hours on this too     and agree that FLAG ACTIVITY CLEAR TOP sounds like what you d want  clear the entire stack  except for the activity being launched  so the Back button exits the application  Yet as Mike Repass mentioned  FLAG ACTIVITY CLEAR TOP only works when the activity you re launching is already in the stack  when the activity s not there  the flag doesn t do anything   What to do  Put the activity being launching in the stack with FLAG ACTIVITY NEW TASK  which makes that activity the start of a new task on the history stack  Then add the FLAG ACTIVITY CLEAR TOP flag   Now  when FLAG ACTIVITY CLEAR TOP goes to find the new activity in the stack  it ll be there and be pulled up before everything else is cleared   Here s my logout function  the View parameter is the button to which the function s attached   public void onLogoutClick final View view        Intent i   new Intent this  Splash class       i setFlags Intent FLAG ACTIVITY NEW TASK   Intent FLAG ACTIVITY CLEAR TASK       startActivity i       finish

User · Answer

Immediately after you start a new activity  using startActivity  make sure you call finish   so that the current activity is not stacked behind the new one

User · Answer

For me none of the above methods not work   Just do this to clear all previous activity   finishAffinity      if you are in fragment use activity finishAffinity   Intent intent   new Intent this  DestActivity class      with all flags you want startActivity intent

User · Answer

Intent i   new Intent MainPoliticalLogin this  MainActivity class   i setFlags Intent FLAG ACTIVITY NEW TASK   Intent FLAG ACTIVITY CLEAR TASK   startActivity i

User · Answer

Case 1 Only two activity A and B    Here Activity flow is A- B  On clicking backbutton from B we need to close the application then while starting Activity B from A just call finish   this will prevent android from storing Activity A in to the Backstack eg for activity A is Loding Splash screen of application   Intent newIntent   new Intent A this  B class   startActivity newIntent   finish      Case 2 More than two activitiy    If there is a flow like A- B- C- D- B and on clicking back button in Activity B while coming from Activity D In that case we should use   Intent newIntent   new Intent D this B class   newIntent addFlags Intent FLAG ACTIVITY CLEAR TOP    newIntent addFlags Intent FLAG ACTIVITY NEW TASK   startActivity newIntent     Here Activity B will be started from the backstack rather than a new instance because of Intent FLAG ACTIVITY CLEAR TOP and Intent FLAG ACTIVITY NEW TASK clears the stack and makes it the top one So when we press back button the whole application will be terminated

User · Answer

In API level 11 a new Intent Flag was added just for this  Intent FLAG ACTIVITY CLEAR TASK Just to clarify  use this  Java intent setFlags Intent FLAG ACTIVITY NEW TASK   Intent FLAG ACTIVITY CLEAR TASK     Kotlin intent flags   Intent FLAG ACTIVITY NEW TASK or Intent FLAG ACTIVITY CLEAR TASK   Unfortunately for API lvl  lt   10  I haven t yet found a clean solution to this  The  quot DontHackAndroidLikeThis quot  solution is indeed pure hackery  You should not do that     Edit  As per  Ben Pearson s comment  for API  lt  10 now one can use IntentCompat class for the same  One can use IntentCompat FLAG ACTIVITY CLEAR TASK flag to clear task  So you can support pre API level 11 as well

User · Answer

Advanced Reuseable Kotlin   You can set the flag directly using setter method  In Kotlin or is the replacement for the Java bitwise or     intent flags   FLAG ACTIVITY NEW TASK or FLAG ACTIVITY CLEAR TASK   If you plan to use this regularly  create an Intent extension function  fun Intent clearStack         flags   Intent FLAG ACTIVITY NEW TASK or Intent FLAG ACTIVITY CLEAR TASK     You can then directly call this function before starting the intent  intent clearStack     If you need the option to add additional flags in other situations  add an optional param to the extension function   fun Intent clearStack additionalFlags  Int   0        flags   additionalFlags or Intent FLAG ACTIVITY NEW TASK or Intent FLAG ACTIVITY CLEAR TASK

User · Answer

Sometimes your android emulator might fails to connect eclipse DDMS tool and ask for adb to start manually  In that case you can start or stop the adb using the command prompt

User · Answer

I found too simple hack just do this add new element in  AndroidManifest as -    lt activity android name   activityName            android label   string app name            android noHistory  true   gt    the android noHistory will clear your unwanted activity from Stack

User · Answer

Try this   Intent logout intent   new Intent DashboardActivity this  LoginActivity class   logout intent setFlags Intent FLAG ACTIVITY CLEAR TOP   logout intent setFlags Intent FLAG ACTIVITY NEW TASK   logout intent setFlags Intent FLAG ACTIVITY NO HISTORY   startActivity logout intent   finish

User · Answer

You shouldn t change the stack  Android back button should work as in a web browser   I can think of a way to do it  but it s quite a hack    Make your Activities singleTask by adding it to the AndroidManifest Example    lt activity android name   activities A            android label   string A title            android launchMode  singleTask   gt    lt activity android name   activities B            android label   string B title            android launchMode  singleTask   gt   Extend Application which will hold the logic of where to go    Example   public class DontHackAndroidLikeThis extends Application      private Stack lt Activity gt  classes   new Stack lt Activity gt        public Activity getBackActivity         return classes pop           public void addBackActivity Activity activity        classes push activity           From A to B   DontHackAndroidLikeThis app    DontHackAndroidLikeThis  getApplication    app addBackActivity A class    startActivity this  B class     From B to C   DontHackAndroidLikeThis app    DontHackAndroidLikeThis  getApplication    app addBackActivity B class    startActivity this  C class     In C   If   shouldNotGoBackToB         DontHackAndroidLikeThis app    DontHackAndroidLikeThis  getApplication      app pop        and handle the back button to pop   from the stack   Once again  you shouldn t do this

User · Answer

Try below code   Intent intent   new Intent ManageProfileActivity this  LoginActivity class   intent addFlags Intent FLAG ACTIVITY CLEAR TOP                  Intent FLAG ACTIVITY CLEAR TASK                   Intent FLAG ACTIVITY NEW TASK   startActivity intent

[android] Clear the entire history stack and start a new activity on Android

Examples related to android

Examples related to android-activity

Examples related to back-stack