and did you use that constructor? because the code snippet shows you've used the default constructor
On Sunday, September 15, 2013 1:52:22 PM UTC+3, Greenhand wrote: > > Thanks for pointing out the mistakes. The whole code is too long to post > and maintain readability so I just put some snippet. The "MyAsyncTask > having a constructor named GetTokenAsyncTask" is a typo, the constructor > should named MyAsyncTask. > As for ProgressFragment, I use its toString() method to check using > Log.d(). They are the same across rotation. > > > > 2013/9/15 Piren <[email protected] <javascript:>> > >> It's hard to follow your code since it seems some of it is incorrect >> (like MyAsyncTask having a constructor named GetTokenAsyncTask) and some >> of it is missing... >> Either way you should verify you actually used that constructor (in the >> current code you don't, so the member "fragment" is null).Either case, you >> should also verify that the proper ProgressFragment is being set during >> onAttach of FragmentA since i assume a new one will be created after >> rotation (though i'm not sure about that). >> >> Since this isn't that much code, you should probably just find a tutorial >> on how to do that (there's a lot of those online) and start from scratch >> (just so you wouldn't miss something) >> >> On Sunday, September 15, 2013 1:30:20 PM UTC+3, Greenhand wrote: >>> >>> I use appcompat library to host some fragments for tabs. In a specific >>> fragment A, I need to do network operation. In order not to block the UI >>> thread, I use an AsyncTask and do the network operation in >>> doInBackGround(). >>> >>> To prevent messing around keep AsyncTask to survive rotation in the >>> fragment, I call setRetainInstance(true) in the fragment A oncreate(). >>> >>> It works fine but I need to prompt user something when the network >>> operation is in progress. Therefore, I use DialogFragment. In the >>> DialogFragment onCreateView(), it instantiates a ProgressDialog and returns. >>> >>> To be concrete, the following is the code snippets of FragmentA, >>> MyDialogFragment and AsyncTask : >>> public class FragmentA extends Fragment{ //as tab for actionbar >>> (appcompat) >>> private boolean isNetworkOperationCalled; >>> private MyDialogFragment myDialogFragment; >>> ... >>> public void showProgressDialog(){ //for MyAsyncTask#onPreExecute() >>> myDialogFragment = new MyDialogFragment(); >>> myDialogFragment.show(**getFragmentManager(), "mydialog"); >>> } >>> public void showProgressDialog(){ //for MyAsyncTask#onPostExecute() >>> myDialogFragment.dismiss(); >>> } >>> public void onResume() { >>> if(!**isNetworkOperationCalled){ >>> isNetworkOperationCalled=true; >>> new MyAsyncTask.execute();//do the network operation >>> } >>> } >>> ... >>> } >>> >>> >>> public class MyDialogFragment extends DialogFragment{ //ProgressDialog >>> for FragmentA >>> ... >>> public Dialog onCreateDialog(Bundle savedInstanceState) { >>> ProgressDialog progressDialog = new ProgressDialog(getActivity(),** >>> ProgressDialog.STYLE_SPINNER); >>> ... //set the dialog attributes >>> return progressDialog; >>> } >>> ... >>> } >>> public class MyAsyncTask extends AsyncTask<Void,Void,Void>{ //do network >>> operation >>> private Fragment fragment; >>> >>> public GetTokenAsyncTask(Fragment fragmentA){ >>> fragment = fragmentA; >>> } >>> protected void onPreExecute() { >>> fragment.showProgressDialog(**); //show progess dialog for users >>> } >>> protected String doInBackground(Void... arg0) { >>> ... >>> } >>> protected void onPostExecute() { //dismiss the dialog >>> fragment.**dismissProgressDialog(); >>> } >>> } >>> In a nutshell, fragment A triggers AsyncTask and AsyncTask call methods >>> of FragmentA to show/dismiss dialog. Fragment A use MyDialogFragment to >>> show the progress dialog. >>> >>> The code (method) above works if there is no rotataion occurs while >>> doInBackground() is executing. Nevertheless, if the rotation happens before >>> onPostExecute() is called, >>> the rotation is fine and the progress dialog is retained. Sadly, it >>> crashes when onPostExecute() finally be called when dismissing the dialog. >>> >>> E/AndroidRuntime(27493): FATAL EXCEPTION: main >>> E/AndroidRuntime(27493): java.lang.NullPointerException >>> E/AndroidRuntime(27493): at android.support.v4.app.**DialogFragment.** >>> dismissInternal(**DialogFragment.java:184) >>> E/AndroidRuntime(27493): at android.support.v4.app.** >>> DialogFragment.dismiss(**DialogFragment.java:155) >>> E/AndroidRuntime(27493): at com.example.FragmentA.** >>> dismissProgressDialog(**FragmentA.java:105) >>> E/AndroidRuntime(27493): at com.example.FragmentA.access$** >>> 1(FragmentA.java:103) >>> E/AndroidRuntime(27493): at com.example.FragmentA$**GetTokenAsyncTask.* >>> *onPostExecute(FragmentA.java:**40) >>> E/AndroidRuntime(27493): at com.example.FragmentA$**GetTokenAsyncTask.* >>> *onPostExecute(FragmentA.java:**1) >>> E/AndroidRuntime(27493): at android.os.AsyncTask.finish(** >>> AsyncTask.java:631) >>> E/AndroidRuntime(27493): at android.os.AsyncTask.access$** >>> 600(AsyncTask.java:177) >>> E/AndroidRuntime(27493): at android.os.AsyncTask$** >>> InternalHandler.handleMessage(**AsyncTask.java:644) >>> E/AndroidRuntime(27493): at android.os.Handler.** >>> dispatchMessage(Handler.java:**99) >>> E/AndroidRuntime(27493): at android.os.Looper.loop(Looper.**java:137) >>> E/AndroidRuntime(27493): at android.app.ActivityThread.** >>> main(ActivityThread.java:4875) >>> E/AndroidRuntime(27493): at java.lang.reflect.Method.**invokeNative(Native >>> Method) >>> E/AndroidRuntime(27493): at java.lang.reflect.Method.** >>> invoke(Method.java:511) >>> E/AndroidRuntime(27493): at com.android.internal.os.**ZygoteInit$** >>> MethodAndArgsCaller.run(**ZygoteInit.java:804) >>> E/AndroidRuntime(27493): at com.android.internal.os.** >>> ZygoteInit.main(ZygoteInit.**java:571) >>> E/AndroidRuntime(27493): at dalvik.system.NativeStart.**main(Native >>> Method) >>> >>> How can I solve the problem so that the dialog can dismiss correctly >>> after rotation? >>> >> -- >> You received this message because you are subscribed to the Google >> Groups "Android Developers" group. >> To post to this group, send email to >> [email protected]<javascript:> >> To unsubscribe from this group, send email to >> [email protected] <javascript:> >> For more options, visit this group at >> http://groups.google.com/group/android-developers?hl=en >> --- >> You received this message because you are subscribed to a topic in the >> Google Groups "Android Developers" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/android-developers/Nzwk2PBQtAQ/unsubscribe >> . >> To unsubscribe from this group and all its topics, send an email to >> [email protected] <javascript:>. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > -- You received this message because you are subscribed to the Google Groups "Android Developers" group. 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