How to handle screen orientation change when progress dialog and background thread active

Question

My program does some network activity in a background thread  Before starting  it pops up a progress dialog  The dialog is dismissed on the handler  This all works fine  except when screen orientation changes while the dialog is up  and the background thread is going   At this point the app either crashes  or deadlocks  or gets into a weird stage where the app does not work at all until all the threads have been killed   How can I handle the screen orientation change gracefully   The sample code below matches roughly what my real program does   public class MyAct extends Activity implements Runnable       public ProgressDialog mProgress          UI has a button that when pressed calls send      public void send              mProgress   ProgressDialog show this   Please wait                           Please wait                          true  true           Thread thread   new Thread this           thread start               public void run             Thread sleep 10000           Message msg   new Message            mHandler sendMessage msg              private final Handler mHandler   new Handler              Override         public void handleMessage Message msg                mProgress dismiss                         Stack   E WindowManager   244   Activity MyAct has leaked window com android internal policy impl PhoneWindow DecorView 433b7150 that was originally added here E WindowManager   244   android view WindowLeaked  Activity MyAct has leaked window com android internal policy impl PhoneWindow DecorView 433b7150 that was originally added here E WindowManager   244       at android view ViewRoot  lt init gt  ViewRoot java 178  E WindowManager   244       at android view WindowManagerImpl addView WindowManagerImpl java 147  E WindowManager   244       at android view WindowManagerImpl addView WindowManagerImpl java 90  E WindowManager   244       at android view Window LocalWindowManager addView Window java 393  E WindowManager   244       at android app Dialog show Dialog java 212  E WindowManager   244       at android app ProgressDialog show ProgressDialog java 103  E WindowManager   244       at android app ProgressDialog show ProgressDialog java 91  E WindowManager   244       at MyAct send MyAct java 294  E WindowManager   244       at MyAct 4 onClick MyAct java 174  E WindowManager   244       at android view View performClick View java 2129  E WindowManager   244       at android view View onTouchEvent View java 3543  E WindowManager   244       at android widget TextView onTouchEvent TextView java 4664  E WindowManager   244       at android view View dispatchTouchEvent View java 3198    I have tried to dismiss the progress dialog in onSaveInstanceState  but that just prevents an immediate crash  The background thread is still going  and the UI is in partially drawn state  Need to kill the whole app before it starts working again

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I faced this same problem  and I came up with a solution that didn t invole using the ProgressDialog and I get faster results   What I did was create a layout that has a ProgressBar in it    lt  xml version  1 0  encoding  utf-8   gt   lt RelativeLayout xmlns android  http   schemas android com apk res android  android layout width  fill parent  android layout height  fill parent  gt   lt ProgressBar     android id    id progressImage      android layout width  wrap content      android layout height  wrap content      android layout centerInParent  true        gt   lt  RelativeLayout gt    Then in the onCreate method do the following  public void onCreate Bundle icicle        super onCreate icicle       setContentView R layout progress       Then do the long task in a thread  and when that s finished have a Runnable set the content view to the real layout you want to use for this activity   For example   mHandler post new Runnable     public void run             setContentView R layout my layout                This is what I did  and I ve found that it runs faster than showing the ProgressDialog and it s less intrusive and has a better look in my opinion   However  if you re wanting to use the ProgressDialog  then this answer isn t for you

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These days there is a much more distinct way to handle these types of issues  The typical approach is   1  Ensure your data is properly seperated from the UI   Anything that is a background process should be in a retained Fragment  set this with Fragment setRetainInstance    This becomes your  persistent data storage  where anything data based that you would like retained is kept  After the orientation change event  this Fragment will still be accessible in its original state through a FragmentManager findFragmentByTag   call  when you create it you should give it a tag not an ID as it is not attached to a View    See the Handling Runtime Changes developed guide for information about doing this correctly and why it is the best option   2  Ensure you are interfacing correctly and safely between the background processs and your UI   You must reverse your linking process  At the moment your background process attaches itself to a View - instead your View should be attaching itself to the background process  It makes more sense right  The View s action is dependent on the background process  whereas the background process is not dependent on the View This means changing the link to a standard Listener interface  Say your process  whatever class it is - whether it is an AsyncTask  Runnable or whatever   defines a OnProcessFinishedListener  when the process is done it should call that listener if it exists   This answer is a nice concise description of how to do custom listeners   3  Link your UI into the data process whenever the UI is created  including orientation changes    Now you must worry about interfacing the background task with whatever your current View structure is  If you are handling your orientation changes properly  not the configChanges hack people always recommend   then your Dialog will be recreated by the system  This is important  it means that on the orientation change  all your Dialog s lifecycle methods are recalled  So in any of these methods  onCreateDialog is usually a good place   you could do a call like the following     DataFragment f   getActivity   getFragmentManager   findFragmentByTag  BACKGROUND TAG    if  f    null        f mBackgroundProcess setOnProcessFinishedListener new OnProcessFinishedListener             public void onProcessFinished                 dismiss                           See the Fragment lifecycle for deciding where setting the listener best fits in your individual implementation     This is a general approach to providing a robust and complete solution to the generic problem asked in this question  There is probably a few minor pieces missing in this answer depending on your individual scenario  but this is generally the most correct approach for properly handling orientation change events

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This is a very old question that came up on the sidebar for some reason   If the background task only needs to survive while the activity is in the foreground  the  new  solution is to host the background thread  or  preferably  AsyncTask  in a retained fragment  as described in this developer guide and numerous Q amp As   A retained fragment survives if the activity is destroyed for a configuration change  but not when the activity is destroyed in the background or back stack   Therefore  the background task should still be interrupted if isChangingConfigurations   is false in onPause

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I ve tried EVERYTHING  Spent days experimenting  I didn t want to block the activity from rotating  My scenario was    A progress dialog showing dynamic information to the user  E g    Connecting to server       Downloading data      etc  A thread doing the heavy stuff and updating the dialog Updating the UI with the results at the end    The problem was  when rotating the screen  every solution on the book failed  Even with the AsyncTask class  which is the correct Android way of dealing with this situations  When rotating the screen  the current Context that the starting thread is working with  is gone  and that messes up with the dialog that is showing  The problem was always the Dialog  no matter how many tricks I added to the code  passing new contexts to running threads  retaining thread states through rotations  etc      The code complexity at the end was always huge and there was always something that could go wrong   The only solution that worked for me was the Activity Dialog trick  It s simple and genius and it s all rotation proof    Instead of creating a Dialog and ask to show it  create an Activity that has been set in the manifest with android theme   android style Theme Dialog   So  it just looks like a dialog  Replace showDialog DIALOG ID  with startActivityForResult yourActivityDialog  yourCode   Use onActivityResult in the calling Activity to get the results from the executing thread  even the errors  and update the UI  On your  ActivityDialog   use threads or AsyncTask to execute long tasks and onRetainNonConfigurationInstance to save  dialog  state when rotating the screen    This is fast and works fine  I still use dialogs for other tasks and the AsyncTask for something that doesn t require a constant dialog on screen  But with this scenario  I always go for the Activity Dialog pattern   And  I didn t try it  but it s even possible to block that Activity Dialog from rotating  when the thread is running  speeding things up  while allowing the calling Activity to rotate

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Tried to implement jfelectron s solution because it is a  rock-solid solution to these issues that conforms with the  Android Way  of things  but it took some time to look up and put together all the elements mentioned  Ended up with this slightly different  and I think more elegant  solution posted here in it s entirety    Uses an IntentService fired from an activity to perform the long running task on a separate thread  The service fires back sticky Broadcast Intents to the activity which update the dialog  The Activity uses showDialog    onCreateDialog   and onPrepareDialog   to eliminate the need to have persistent data passed in the application object or the savedInstanceState bundle  This should work no matter how your application is interrupted   Activity Class   public class TesterActivity extends Activity   private ProgressDialog mProgressDialog  private static final int PROGRESS DIALOG   0    Override public void onCreate Bundle savedInstanceState        super onCreate savedInstanceState       setContentView R layout main        Button b    Button  this findViewById R id test button       b setOnClickListener new OnClickListener             public void onClick View v                buttonClick                         private void buttonClick        clearPriorBroadcast        showDialog PROGRESS DIALOG       Intent svc   new Intent this  MyService class       startService svc      protected Dialog onCreateDialog int id        switch id        case PROGRESS DIALOG          mProgressDialog   new ProgressDialog TesterActivity this           mProgressDialog setProgressStyle ProgressDialog STYLE HORIZONTAL           mProgressDialog setMax MyService MAX COUNTER           mProgressDialog setMessage  Processing               return mProgressDialog      default          return null            Override protected void onPrepareDialog int id  Dialog dialog        switch id        case PROGRESS DIALOG             setup a broadcast receiver to receive update events from the long running process         IntentFilter filter   new IntentFilter            filter addAction MyService BG PROCESS INTENT           registerReceiver new MyBroadcastReceiver    filter           break           public class MyBroadcastReceiver extends BroadcastReceiver       Override     public void onReceive Context context  Intent intent            if  intent hasExtra MyService KEY COUNTER                int count   intent getIntExtra MyService KEY COUNTER  0               mProgressDialog setProgress count               if  count  gt   MyService MAX COUNTER                   dismissDialog PROGRESS DIALOG                                          Sticky broadcasts persist and any prior broadcast will trigger in the     broadcast receiver as soon as it is registered     To clear any prior broadcast this code sends a blank broadcast to clear     the last sticky broadcast     This broadcast has no extras it will be ignored in the broadcast receiver     setup in onPrepareDialog       private void clearPriorBroadcast        Intent broadcastIntent   new Intent        broadcastIntent setAction MyService BG PROCESS INTENT       sendStickyBroadcast broadcastIntent        IntentService Class   public class MyService extends IntentService    public static final String BG PROCESS INTENT    com mindspiker Tester MyService TEST   public static final String KEY COUNTER    counter   public static final int MAX COUNTER   100   public MyService       super          Override protected void onHandleIntent Intent intent        for  int i   0  i  lt   MAX COUNTER  i              Log e  Service Example         i           try               Thread sleep 100             catch  InterruptedException e                e printStackTrace                       Intent broadcastIntent   new Intent            broadcastIntent setAction BG PROCESS INTENT           broadcastIntent putExtra KEY COUNTER  i           sendStickyBroadcast broadcastIntent              Manifest file entries   before application section   uses-permission android name  com mindspiker Tester MyService TEST  uses-permission android name  android permission BROADCAST STICKY    inside application section  service android name   MyService

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I came up with a rock-solid solution for these issues that conforms with the  Android Way  of things  I have all my long-running operations using the IntentService pattern   That is  my activities broadcast intents  the IntentService does the work  saves the data in the DB and then broadcasts sticky intents  The sticky part is important  such that even if the Activity was paused during during the time after the user initiated the work and misses the real time broadcast from the IntentService we can still respond and pick up the data from the calling Activity  ProgressDialogs can work with this pattern quite nicely with onSaveInstanceState     Basically  you need to save a flag that you have a progress dialog running in the saved instance bundle  Do not save the progress dialog object because this will leak the entire Activity  To have a persistent handle to the progress dialog  I store it as a weak reference in the application object  On orientation change or anything else that causes the Activity to pause  phone call  user hits home etc   and then resume  I dismiss the old dialog and recreate a new dialog in the newly created Activity   For indefinite progress dialogs this is easy  For progress bar style  you have to put the last known progress in the bundle and whatever information you re using locally in the activity to keep track of the progress  On restoring the progress  you ll use this information to re-spawn the progress bar in the same state as before and then update based on the current state of things   So to summarize  putting long-running tasks into an IntentService coupled with judicious use of onSaveInstanceState   allows you to efficiently keep track of dialogs and restore then across the Activity life-cycle events  Relevant bits of Activity code are below  You ll also need logic in your BroadcastReceiver to handle Sticky intents appropriately  but that is beyond the scope of this   public void doSignIn View view        waiting true      AppClass app  AppClass  getApplication        String logingon getString R string signon       app Dialog new WeakReference lt ProgressDialog gt  ProgressDialog show AddAccount this      logingon  true                Override protected void onSaveInstanceState Bundle saveState        super onSaveInstanceState saveState       saveState putBoolean  waiting  waiting       Override public void onCreate Bundle savedInstanceState        super onCreate savedInstanceState       if savedInstanceState  null            restoreProgress savedInstanceState                        private void restoreProgress Bundle savedInstanceState        waiting savedInstanceState getBoolean  waiting        if  waiting            AppClass app  AppClass  getApplication            ProgressDialog refresher  ProgressDialog  app Dialog get            refresher dismiss            String logingon getString R string signon           app Dialog new WeakReference lt ProgressDialog gt  ProgressDialog show AddAccount this      logingon  true

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I have an implementation which allows the activity to be destroyed on a screen orientation change  but still destroys the dialog in the recreated activity successfully   I use    NonConfigurationInstance to attach the background task to the recreated activity   The normal Android framework handles recreating the dialog itself  nothing is changed there   I subclassed AsyncTask adding a field for the  owning  activity  and a method to update this owner   class MyBackgroundTask extends AsyncTask lt     gt      MyBackgroundTask  Activity a             super        this ownerActivity   a         public void attach Activity a        ownerActivity   a         protected void onPostExecute Integer result        super onPostExecute result       ownerActivity dismissDialog DIALOG PROGRESS                  In my activity class I added a field backgroundTask referring to the  owned  backgroundtask  and I update this field using onRetainNonConfigurationInstance and getLastNonConfigurationInstance   class MyActivity extends Activity     public void onCreate Bundle savedInstanceState                if  getLastNonConfigurationInstance      null          backgroundTask    MyBackgroundTask  getLastNonConfigurationInstance          backgroundTask attach this                void startBackgroundTask         backgroundTask   new MyBackgroundTask this            showDialog DIALOG PROGRESS       backgroundTask execute              public Object onRetainNonConfigurationInstance         if  backgroundTask    null  amp  amp  backgroundTask getStatus      Status FINISHED        return backgroundTask      return null                Suggestions for further improvement    Clear the backgroundTask reference in the activity after the task is finished to release any memory or other resources associated with it  Clear the ownerActivity reference in the backgroundtask before the activity is destroyed in case it will not be recreated immediately  Create a BackgroundTask interface and or collection to allow different types of tasks to run from the same owning activity

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I faced the same situation  What I did was get only one instance for my progress dialog in the entire application   First  I created a DialogSingleton class to get only one instance  Singleton pattern   public class DialogSingleton       private static Dialog dialog       private static final Object mLock   new Object        private static DialogSingleton instance       private DialogSingleton                     public static DialogSingleton GetInstance                 synchronized  mLock                        if instance    null                                instance   new DialogSingleton                               return instance                       public void DialogShow Context context  String title                if    Activity context  isFinishing                          dialog   new ProgressDialog context  2                dialog setCanceledOnTouchOutside false                dialog setTitle title                dialog show                         public void DialogDismiss Context context                if    Activity context  isFinishing    amp  amp  dialog isShowing                          dialog dismiss                        As I show in this class  I have the progress dialog as attribute  Every time I need to show a progress dialog  I get the unique instance and create a new ProgressDialog    DialogSingleton GetInstance   DialogShow this   My title here       When I am done with the background task  I call again the unique instance and dismiss its dialog   DialogSingleton GetInstance   DialogDismiss this     I save the background task status in my shared preferences  When I rotate the screen  I ask if I have a task running for this activity   onCreate   if Boolean parseBoolean preference GetValue IS TASK NAME EXECUTED KEY   boolean   toString           DialogSingleton GetInstance   DialogShow this   Checking credentials          preference object gets the info from shared preferences  my own implementation to get and put data to shared preferences  and IS TASK NAME EXECUTED KEY is the key to save this flag  flag to know if this activity has a background task already running     When I start running a background task   preference AddValue IS TASK NAME EXECUTED KEY  true   boolean     DialogSingleton GetInstance   DialogShow this   My title here       When I finish running a background task   preference AddValue IS TASK NAME EXECUTED KEY  false   boolean     DialogSingleton GetInstance   DialogDismiss ActivityName this     I hope it helps

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I am a fresher in android and I tried this and it s worked   public class loadTotalMemberByBranch extends AsyncTask lt Void  Void Void gt            ProgressDialog progressDialog   new ProgressDialog Login this           int ranSucess 0           Override         protected void onPreExecute                    TODO Auto-generated method stub             super onPreExecute                progressDialog setTitle                      progressDialog isIndeterminate                progressDialog setCancelable false               progressDialog show                setRequestedOrientation ActivityInfo SCREEN ORIENTATION NOSENSOR                       Override         protected Void doInBackground Void    params                   TODO Auto-generated method stub              return null                     Override         protected void onPostExecute Void result                   TODO Auto-generated method stub             super onPostExecute result               progressDialog dismiss                setRequestedOrientation ActivityInfo SCREEN ORIENTATION NOSENSOR

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i have found and easier solution to handle threads when orientation change  You can just keep an static reference to your activity fragment and verify if its null before acting on the ui  I suggest using a try catch too    public class DashListFragment extends Fragment        private static DashListFragment ACTIVE INSTANCE         Override      public void onCreate Bundle savedInstanceState            super onCreate savedInstanceState            ACTIVE INSTANCE   this           new Handler   postDelayed new Runnable                 public void run                     try                           if  ACTIVE INSTANCE    null                                setAdapter       this method do something on ui or use context                                                             catch  Exception e                                1500l                Override     public void onDestroy             super onDestroy             ACTIVE INSTANCE   null

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The original perceived problem was that the code would not survive a screen orientation change  Apparently this was  solved  by having the program handle the screen orientation change itself  instead of letting the UI framework do it  via calling onDestroy       I would submit that if the underlying problem is that the program will not survive onDestroy    then the accepted solution is just a workaround that leaves the program with serious other problems and vulnerabilities   Remember that the Android framework specifically states that your activity is at risk for being destroyed almost at any time due to circumstances outside your control  Therefore  your activity must be able to survive onDestroy   and subsequent onCreate   for any reason  not just a screen orientation change   If you are going to accept handling screen orientation changes yourself to solve the OP s problem  you need to verify that other causes of onDestroy   do not result in the same error  Are you able to do this   If not  I would question whether the  accepted  answer is really a very good one

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If you create a background Service that does all the heavy lifting  tcp requests response  unmarshalling   the View and Activity can be destroyed and re-created without leaking window or losing data  This allows the Android recommended behavior  which is to destroy an Activity on each configuration change  eg  for each orientation change     It is a bit more complex  but it is the best way for invoking server request  data pre post-processing  etc   You may even use your Service to queue each request to a server  so it makes it easy and efficient to handle those things    The dev guide has a full chapter on Services

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I going to contribute my approach to handling this rotation issue  This may not be relevant to OP as he s not using AsyncTask  but maybe others will find it useful  It s pretty simple but it seems to do the job for me   I have a login activity with a nested AsyncTask class called BackgroundLoginTask   In my BackgroundLoginTask I don t do anything out of the ordinary except to add a null check upon calling ProgressDialog s dismiss    Override protected void onPostExecute Boolean result        if  pleaseWaitDialog    null              pleaseWaitDialog dismiss              This is to handle the case where the background task finishes while the Activity is not visible and  therefore  the progress dialog has already been dismissed by the onPause   method   Next  in my parent Activity class  I create global static handles to my AsyncTask class and my ProgressDialog  the AsyncTask  being nested  can access these variables    private static BackgroundLoginTask backgroundLoginTask  private static ProgressDialog pleaseWaitDialog    This serves two purposes  First  it allows my Activity to always access the AsyncTask object even from a new  post-rotated activity  Second  it allows my BackgroundLoginTask to access and dismiss the ProgressDialog even after a rotate   Next  I add this to onPause    causing the progress dialog to disappear when our Activity is leaving the foreground  preventing that ugly  force close  crash        if  pleaseWaitDialog    null      pleaseWaitDialog dismiss      Finally  I have the following in my onResume   method   if   backgroundLoginTask    null   amp  amp   backgroundLoginTask getStatus      Status RUNNING                        if  pleaseWaitDialog    null               pleaseWaitDialog show                This allows the Dialog to reappear after the Activity is recreated   Here is the entire class   public class NSFkioskLoginActivity extends NSFkioskBaseActivity       private static BackgroundLoginTask backgroundLoginTask      private static ProgressDialog pleaseWaitDialog      private Controller cont          This is the app entry point          Called when the activity is first created          Override     public void onCreate Bundle savedInstanceState            super onCreate savedInstanceState            if  CredentialsAvailableAndValidated                        Go to main menu and don t run rest of onCreate method              gotoMainMenu                return                    setContentView R layout login           populateStoredCredentials                    Save current progress to options when app is leaving foreground      Override     public void onPause                 super onPause            saveCredentialsToPreferences false             Get rid of progress dialog in the event of a screen rotation  Prevents a crash          if  pleaseWaitDialog    null          pleaseWaitDialog dismiss                Override     public void onResume                 super onResume            if   backgroundLoginTask    null   amp  amp   backgroundLoginTask getStatus      Status RUNNING                        if  pleaseWaitDialog    null               pleaseWaitDialog show                                    Go to main menu  finishing this activity             private void gotoMainMenu                 startActivity new Intent getApplicationContext    NSFkioskMainMenuActivity class            finish                                   param setValidatedBooleanTrue If set true  method will set CREDS HAVE BEEN VALIDATED to true in addition to saving username password              private void saveCredentialsToPreferences boolean setValidatedBooleanTrue                SharedPreferences settings   getSharedPreferences APP PREFERENCES  MODE PRIVATE           SharedPreferences Editor prefEditor   settings edit            EditText usernameText    EditText  findViewById R id editTextUsername           EditText pswText    EditText  findViewById R id editTextPassword           prefEditor putString USERNAME  usernameText getText   toString             prefEditor putString PASSWORD  pswText getText   toString             if  setValidatedBooleanTrue          prefEditor putBoolean CREDS HAVE BEEN VALIDATED  true           prefEditor commit                          Checks if user is already signed in             private boolean CredentialsAvailableAndValidated             SharedPreferences settings   getSharedPreferences APP PREFERENCES                  MODE PRIVATE           if  settings contains USERNAME   amp  amp  settings contains PASSWORD   amp  amp  settings getBoolean CREDS HAVE BEEN VALIDATED  false     true           return true             else         return false               Populate stored credentials  if any available     private void populateStoredCredentials                 SharedPreferences settings   getSharedPreferences APP PREFERENCES              MODE PRIVATE           settings getString USERNAME              EditText usernameText    EditText  findViewById R id editTextUsername          usernameText setText settings getString USERNAME               EditText pswText    EditText  findViewById R id editTextPassword          pswText setText settings getString PASSWORD                              Validate credentials in a seperate thread  displaying a progress circle in the meantime        If successful  save credentials in preferences and proceed to main menu activity        If not  display an error message             public void loginButtonClick View view                if  phoneIsOnline                      EditText usernameText    EditText  findViewById R id editTextUsername           EditText pswText    EditText  findViewById R id editTextPassword                Call background task worker with username and password params            backgroundLoginTask   new BackgroundLoginTask               backgroundLoginTask execute usernameText getText   toString    pswText getText   toString                       else                     Display toast informing of no internet access         String notOnlineMessage   getResources   getString R string noNetworkAccessAvailable           Toast toast   Toast makeText getApplicationContext    notOnlineMessage  Toast LENGTH SHORT           toast show                                            Takes two params  username and password                    public class BackgroundLoginTask extends AsyncTask lt Object  String  Boolean gt                      private Exception e   null           Override        protected void onPreExecute                       cont   Controller getInstance                 Show progress dialog            String pleaseWait   getResources   getString R string pleaseWait              String commWithServer   getResources   getString R string communicatingWithServer               if  pleaseWaitDialog    null                pleaseWaitDialog  ProgressDialog show NSFkioskLoginActivity this  pleaseWait  commWithServer  true                       Override         protected Boolean doInBackground Object    params                    try                 Returns true if credentials were valid  False if not  Exception if server could not be reached              return cont validateCredentials  String params 0    String params 1              catch  Exception e                this e e              return false                                              result is passed from doInBackground  Indicates whether credentials were validated                       Override         protected void onPostExecute Boolean result                      Hide progress dialog and handle exceptions           Progress dialog may be null if rotation has been switched         if  pleaseWaitDialog    null                             pleaseWaitDialog dismiss                    pleaseWaitDialog   null                          if  e    null                       Show toast with exception text                 String networkError   getResources   getString R string serverErrorException                   Toast toast   Toast makeText getApplicationContext    networkError  Toast LENGTH SHORT               toast show                      else                       if  result    true                            saveCredentialsToPreferences true               gotoMainMenu                              else                           String toastText   getResources   getString R string invalidCredentialsEntered                   Toast toast   Toast makeText getApplicationContext    toastText  Toast LENGTH SHORT               toast show                                                  I am by no means a seasoned Android developer  so feel free to comment

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If you maintain two layouts  all UI thread should be terminated    If you use AsynTask  then you can easily call  cancel   method inside onDestroy   method of current activity    Override protected void onDestroy         removeDialog DIALOG LOGIN ID      remove loading dialog     if  loginTask    null           if  loginTask getStatus      AsyncTask Status FINISHED              loginTask cancel true     cancel AsyncTask           super onDestroy        For AsyncTask  read more in  Cancelling a task  section at here   Update  Added condition to check status  as it can be only cancelled if it is in running state  Also note that the AsyncTask can only be executed one time

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When you change orientations   Android kill that activity and created new activity   I suggest to use retrofit with Rx java   which handle crashes automatically    Use these method when retrofit call    subscribeOn Schedulers io     observeOn AndroidSchedulers mainThread

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Move the long task to a seperate class  Implement it as a subject-observer pattern  Whenever the activity is created register and while closing unregister with the task class  Task class can use AsyncTask

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I have done it like this       package com palewar      import android app Activity      import android app ProgressDialog      import android os Bundle      import android os Handler      import android os Message       public class ThreadActivity extends Activity             static ProgressDialog dialog          private Thread downloadThread          final static Handler handler   new Handler                   Override             public void handleMessage Message msg                     super handleMessage msg                    dialog dismiss                                        protected void onDestroy         super onDestroy                if  dialog    null  amp  amp  dialog isShowing                      dialog dismiss                    dialog   null                                        Called when the activity is first created              Override         public void onCreate Bundle savedInstanceState                super onCreate savedInstanceState               setContentView R layout main                downloadThread    Thread  getLastNonConfigurationInstance                if  downloadThread    null  amp  amp  downloadThread isAlive                      dialog   ProgressDialog show ThreadActivity this                               Signing in      false                              dialog   ProgressDialog show ThreadActivity this                           Signing in       false                downloadThread   new MyThread                downloadThread start                   processThread                          Save the thread          Override         public Object onRetainNonConfigurationInstance                 return downloadThread                      static public class MyThread extends Thread                Override             public void run                      try                          Simulate a slow network                     try                           new Thread   sleep 5000                         catch  InterruptedException e                            e printStackTrace                                              handler sendEmptyMessage 0                      finally                                                       You can also try and let me know it works for you or not

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When you switch orientations  Android will create a new View   You re probably getting crashes because your background thread is trying to change the state on the old one    It may also be having trouble because your background thread isn t on the UI thread   I d suggest making that mHandler volatile and updating it when the orientation changes

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This is my proposed solution    Move the AsyncTask or Thread to a retained Fragment  as explained here  I believe it is a good practice to move all network calls to fragments  If you are already using fragments  one of them could be made responsible for the calls  Otherwise  you can create a fragment just for doing the request  as the linked article proposes  The fragment will use a listener interface to signal the task completion failure  You don t have to worry for orientation changes there  The fragment will always have the correct link to the current activity and progress dialog can be safely resumed  Make your progress dialog a member of your class  In fact you should do that for all dialogs  In the onPause method you should dismiss them  otherwise you will leak a window on the configuration change  The busy state should be kept by the fragment  When the fragment is attached to the activity  you can bring up the progress dialog again  if the call is still running  A void showProgressDialog   method can be added to the fragment-activity listener interface for this purpose

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The simplest and most flexible solution is to use an AsyncTask with a static reference to ProgressBar  This provides an encapsulated and thus reusable solution to orientation change problems  This solution has served me well for varying asyncronous tasks including internet downloads  communicating with Services  and filesystem scans  The solution has been well tested on multiple android versions and phone models  A complete demo can be found here with specific interest in DownloadFile java  I present the following as a concept example  public class SimpleAsync extends AsyncTask lt String  Integer  String gt        private static ProgressDialog mProgressDialog   null      private final Context mContext       public SimpleAsync Context context            mContext   context          if   mProgressDialog    null                 onPreExecute                          Override     protected void onPreExecute             mProgressDialog   new ProgressDialog  mContext            mProgressDialog show                Override     protected void onPostExecute String result            if   mProgressDialog    null                 mProgressDialog dismiss                mProgressDialog   null                        Override     protected void onProgressUpdate Integer    progress            mProgressDialog setProgress  progress 0                 Override     protected String doInBackground String    sUrl               Do some work here         publishProgress 1           return null             public void dismiss             if   mProgressDialog    null                 mProgressDialog dismiss                        Usage in an Android Activity is simple  public class MainActivity extends Activity       DemoServiceClient mClient   null      DownloadFile mDownloadFile   null        Override     public void onCreate Bundle savedInstanceState            super onCreate  savedInstanceState            setContentView  R layout main            mDownloadFile   new DownloadFile  this             Button downloadButton    Button  findViewById  R id download file button            downloadButton setOnClickListener  new View OnClickListener                  Override             public void onClick View view                    mDownloadFile execute   http   www textfiles com food bakebred txt                                          Override     public void onPause             super onPause            mDownloadFile dismiss

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Seems far too  quick and dirty  to be true so please point out the flaws but what I found worked was     Within the onPostExecute method of my AsyncTask  I simply wrapped the   dismiss  for the progress dialog in a try catch block  with an empty catch  and then simply ignored the exception that was raised  Seems wrong to do but appears there are no ill effects  at least for what I am doing subsequently which is to start another activity passing in the result of my long running query as an Extra

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I discovered a solution to this that I haven t yet seen elsewhere  You can use a custom application object that knows if you have background tasks going  instead of trying to do this in the activity that gets destroyed and recreated on orientation change  I blogged about this in here

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The trick is to show dismiss the dialog within AsyncTask during onPreExecute onPostExecute as usual  though in case of orientation-change create show a new instance of the dialog in the activity and pass its reference to the task   public class MainActivity extends Activity       private Button mButton      private MyTask mTask   null        Override     public void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout main            MyTask task    MyTask  getLastNonConfigurationInstance            if task    null               mTask   task              mTask mContext   this              mTask mDialog   ProgressDialog show this          true                              mButton    Button  findViewById R id button1           mButton setOnClickListener new View OnClickListener                public void onClick View v                   mTask   new MyTask MainActivity this                   mTask execute                                           Override     public Object onRetainNonConfigurationInstance             String str    null           if mTask    null               str   mTask toString                mTask mDialog dismiss                      Toast makeText this  str  Toast LENGTH SHORT  show            return mTask               private class MyTask extends AsyncTask lt Void  Void  Void gt           private ProgressDialog mDialog          private MainActivity mContext            public MyTask MainActivity context               super                mContext   context                      protected void onPreExecute                 mDialog   ProgressDialog show MainActivity this          true                      protected void onPostExecute Void result                mContext mTask   null              mDialog dismiss                         Override         protected Void doInBackground Void    params                SystemClock sleep 5000               return null

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Edit  Google engineers do not recommend this approach  as described by Dianne Hackborn  a k a  hackbod  in this StackOverflow post  Check out this blog post for more information     You have to add this to the activity declaration in the manifest   android configChanges  orientation screenSize    so it looks like   lt activity android label   string app name           android configChanges  orientation screenSize keyboardHidden           android name   your package  gt    The matter is that the system destroys the activity when a change in the configuration occurs  See ConfigurationChanges   So putting that in the configuration file avoids the system to destroy your activity  Instead it invokes the onConfigurationChanged Configuration  method

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My solution was to extend the ProgressDialog class to get my own MyProgressDialog  I redefined show   and dismiss   methods to lock the orientation before showing the Dialog and unlock it back when Dialog is dismissed  So when the Dialog is shown and the orientation of the device changes  the orientation of the screen remains until dismiss   is called  then screen-orientation changes according to sensor-values device-orientation  Here is my code  public class MyProgressDialog extends ProgressDialog       private Context mContext       public MyProgressDialog Context context            super context           mContext   context             public MyProgressDialog Context context  int theme            super context  theme           mContext   context                 public void show             if  mContext getResources   getConfiguration   orientation    Configuration ORIENTATION PORTRAIT                Activity  mContext  setRequestedOrientation ActivityInfo SCREEN ORIENTATION PORTRAIT           else               Activity  mContext  setRequestedOrientation ActivityInfo SCREEN ORIENTATION LANDSCAPE           super show                   public void dismiss             super dismiss              Activity  mContext  setRequestedOrientation ActivityInfo SCREEN ORIENTATION SENSOR

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I met the same problem  My activity needs to parse some data from a URL and it s slow  So I create a thread to do so  then show a progress dialog  I let the thread post a message back to UI thread via Handler when it s finished  In Handler handleMessage  I get the data object  ready now  from thread and populate it to UI  So it s very similar to your example   After a lot of trial and error it looks like I found a solution  At least now I can rotate screen at any moment  before or after the thread is done  In all tests  the dialog is properly closed and all behaviors are as expected   What I did is shown below  The goal is to fill my data model  mDataObject  and then populate it to UI  Should allow screen rotation at any moment without surprise   class MyActivity        private MyDataObject mDataObject   null      private static MyThread mParserThread   null     static  or make it singleton      OnCreate                         Object retained   this getLastNonConfigurationInstance            if retained    null                   data is already completely obtained before config change                by my previous self                 no need to create thread or show dialog at all             mDataObject    MyDataObject  retained              populateUI              else if mParserThread    null  amp  amp  mParserThread isAlive                    note  mParserThread is a static member or singleton object                 config changed during parsing in previous instance  swap handler                then wait for it to finish              mParserThread setHandler new MyHandler               else                  no data and no thread  likely initial run                create thread  show dialog             mParserThread   new MyThread      new MyHandler                 mParserThread start                showDialog DIALOG PROGRESS                           http   android-developers blogspot com 2009 02 faster-screen-orientation-change html     public Object onRetainNonConfigurationInstance                my future self can get this without re-downloading            if it s already ready          return mDataObject                use Activity showDialog instead of ProgressDialog show        so the dialog can be automatically managed across config change      Override     protected Dialog onCreateDialog int id               show progress dialog here               inner class of MyActivity     private class MyHandler extends Handler           public void handleMessage msg                mDataObject   mParserThread getDataObject                populateUI                dismissDialog DIALOG PROGRESS                      class MyThread extends Thread       Handler mHandler      MyDataObject mDataObject          constructor with handler param     public MyHandler      Handler h                        mHandler   h             public void setHandler Handler h    mHandler   h       for handler swapping after config change     public MyDataObject getDataObject     return mDataObject       return data object  completed  to caller      public void run             mDataObject   new MyDataObject               do the lengthy task to fill mDataObject with data         lengthyTask mDataObject              done  notify activity         mHandler sendEmptyMessage 0      tell activity  i m ready  come pick up the data            That s what works for me  I don t know if this is the  correct  method as designed by Android -- they claim this  destroy recreate activity during screen rotation  actually makes things easier  so I guess it shouldn t be too tricky   Let me know if you see a problem in my code  As said above I don t really know if there is any side effect

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If you re struggling with detecting orientation change events of a dialog INDEPENDENT OF AN ACTIVITY REFERENCE  this method works excitingly well   I use this because I have my own dialog class that can be shown in multiple different Activities so I don t always know which Activity it s being shown in   With this method you don t need to change the AndroidManifest  worry about Activity references  and you don t need a custom dialog  as I have   You do need  however  a custom content view so you can detect the orientation changes using that particular view  Here s my example   Setup  public class MyContentView extends View      public MyContentView Context context           super context               Override     public void onConfigurationChanged Configuration newConfig           super onConfigurationChanged newConfig              DO SOMETHING HERE    D           Implementation 1 - Dialog  Dialog dialog   new Dialog context     set up dialog dialog setContentView new MyContentView context    dialog show      Implementation 2 - AlertDialog Builder  AlertDialog Builder builder   new AlertDialog Builder context     set up dialog builder builder setView new MyContentView context             Can use this method builder setCustomTitle new MycontentView context       or this method builder build   show      Implementation 3 - ProgressDialog   AlertDialog  ProgressDialog progress   new ProgressDialog context     set up progress dialog progress setView new MyContentView context             Can use this method progress setCustomTitle new MyContentView context       or this method progress show

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This is my solution when I faced it  ProgressDialog is not a Fragment child  so my custom class  ProgressDialogFragment  can extend DialogFragment instead in order to keep the dialog shown for configuration changes   import androidx annotation NonNull  import android app Dialog  import android app ProgressDialog  import android os Bundle   import androidx fragment app DialogFragment  import androidx fragment app FragmentManager           Usage     To display the dialog          gt  gt  gt  ProgressDialogFragment showProgressDialogFragment                  getSupportFragmentManager                      fragment tag                     my dialog title                     my dialog message                        To hide the dialog         gt  gt  gt  ProgressDialogFragment hideProgressDialogFragment           public class ProgressDialogFragment extends DialogFragment        private static String sTitle  sMessage      private static ProgressDialogFragment sProgressDialogFragment       public ProgressDialogFragment                private ProgressDialogFragment String title  String message            sTitle   title          sMessage   message               NonNull      Override     public Dialog onCreateDialog Bundle savedInstanceState            return ProgressDialog show getActivity    sTitle  sMessage              public static void showProgressDialogFragment FragmentManager fragmentManager  String fragmentTag  String title  String message            if  sProgressDialogFragment    null                sProgressDialogFragment   new ProgressDialogFragment title  message               sProgressDialogFragment show fragmentManager  fragmentTag              else      case of config change  device rotation              sProgressDialogFragment    ProgressDialogFragment  fragmentManager findFragmentByTag fragmentTag      sProgressDialogFragment will try to survive its state on configuration as much as it can  but when calling  dismiss   it returns NPE  so we have to reset it on each config change             sTitle   title              sMessage   message                        public static void hideProgressDialogFragment             if  sProgressDialogFragment    null                sProgressDialogFragment dismiss                           The challenge was to retain the dialog title  amp  message while screen   rotation as they reset to the default empty string  although the dialog still shown   There are 2 approaches to solve this   First approach   Make the activity that utilizes the dialog to retain state during config change in manifest file   android configChanges  orientation screenSize keyboardHidden    This approach is not preferred by Google   Second approach  on the activity s onCreate   method  you need to retain your DialogFragment by rebuilding the ProgressDialogFragment again with the title  amp  message as follows if the savedInstanceState is not null    Override protected void onCreate Bundle savedInstanceState     super onCreate savedInstanceState    setContentView R layout activity deal     if  savedInstanceState    null          ProgressDialogFragment saveProgressDialog    ProgressDialogFragment  getSupportFragmentManager                  findFragmentByTag  fragment tag          if  saveProgressDialog    null              showProgressDialogFragment getSupportFragmentManager     fragment tag    my dialog title    my dialog message

[android] How to handle screen orientation change when progress dialog and background thread active?

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