login - My Android alert appears twice after logging in -

i'm testing out notification tells user of android app whether or not there internet connection. have inserted code onresume function, seen below:

@override protected void onresume(){     super.onresume();     alertdialog.builder builder = new alertdialog.builder(this);     builder.setpositivebutton(r.string.ok, new dialoginterface.onclicklistener() {            public void onclick(dialoginterface dialog, int id) {                dialog.dismiss();            }        });     if(isnetworkconnected()){         builder.setmessage(r.string.yes_internet)            .settitle(r.string.title);     }     else{         builder.setmessage(r.string.no_internet)            .settitle(r.string.title);     }     alertdialog dialog = builder.create();     dialog.show(); }  private boolean isnetworkconnected() {       connectivitymanager cm = (connectivitymanager) getsystemservice(context.connectivity_service);       networkinfo ni = cm.getactivenetworkinfo();       if (ni == null) {           // there no active networks.           return false;       }       else{           return true;       } } 

which works fine. except part after log in, see alert, , dismiss it, identical alert appears. happens after logging in, not happen if leave app , come it. login activity (which 1 automatically generated eclipse) called oncreate, run when app launched. so, appear login activity causing onresume called twice. have no idea be.

here code login activity:

/**  * activity displays login screen user, offering registration  * well.  */ public class loginactivity extends activity { /**  * dummy authentication store containing known user names , passwords.  * todo: remove after connecting real authentication system.  */ private static final string[] dummy_credentials = new string[] {         "foo@example.com:hello", "bar@example.com:world" };  /**  * default email populate email field with.  */ public static final string extra_email = "com.example.android.authenticatordemo.extra.email";  /**  * keep track of login task ensure can cancel if requested.  */ private userlogintask mauthtask = null;  // values email , password @ time of login attempt. private string memail; private string mpassword;  // ui references. private edittext memailview; private edittext mpasswordview; private view mloginformview; private view mloginstatusview; private textview mloginstatusmessageview;  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);      setcontentview(r.layout.activity_login);      // set login form.     memail = getintent().getstringextra(extra_email);     memailview = (edittext) findviewbyid(r.id.email);     memailview.settext(memail);      mpasswordview = (edittext) findviewbyid(r.id.password);     mpasswordview             .setoneditoractionlistener(new textview.oneditoractionlistener() {                 @override                 public boolean oneditoraction(textview textview, int id,                         keyevent keyevent) {                     if (id == r.id.login || id == editorinfo.ime_null) {                         attemptlogin();                         return true;                     }                     return false;                 }             });      mloginformview = findviewbyid(r.id.login_form);     mloginstatusview = findviewbyid(r.id.login_status);     mloginstatusmessageview = (textview) findviewbyid(r.id.login_status_message);      findviewbyid(r.id.sign_in_button).setonclicklistener(             new view.onclicklistener() {                 @override                 public void onclick(view view) {                     attemptlogin();                 }             }); }  @override public boolean oncreateoptionsmenu(menu menu) {     super.oncreateoptionsmenu(menu);     getmenuinflater().inflate(r.menu.login, menu);     return true; }  /**  * attempts sign in or register account specified login form.  * if there form errors (invalid email, missing fields, etc.),  * errors presented , no actual login attempt made.  */ public void attemptlogin() {     if (mauthtask != null) {         return;     }      // reset errors.     memailview.seterror(null);     mpasswordview.seterror(null);      // store values @ time of login attempt.     memail = memailview.gettext().tostring();     mpassword = mpasswordview.gettext().tostring();      boolean cancel = false;     view focusview = null;      // check valid password.     if (textutils.isempty(mpassword)) {         mpasswordview.seterror(getstring(r.string.error_field_required));         focusview = mpasswordview;         cancel = true;     } else if (mpassword.length() < 4) {         mpasswordview.seterror(getstring(r.string.error_invalid_password));         focusview = mpasswordview;         cancel = true;     }      // check valid email address.     if (textutils.isempty(memail)) {         memailview.seterror(getstring(r.string.error_field_required));         focusview = memailview;         cancel = true;     } else if (!memail.contains("@")) {         memailview.seterror(getstring(r.string.error_invalid_email));         focusview = memailview;         cancel = true;     }      if (cancel) {         // there error; don't attempt login , focus first         // form field error.         focusview.requestfocus();     } else {         // show progress spinner, , kick off background task         // perform user login attempt.         mloginstatusmessageview.settext(r.string.login_progress_signing_in);         showprogress(true);         mauthtask = new userlogintask();         mauthtask.execute((void) null);     } }  /**  * shows progress ui , hides login form.  */ @targetapi(build.version_codes.honeycomb_mr2) private void showprogress(final boolean show) {     // on honeycomb mr2 have viewpropertyanimator apis, allow     // easy animations. if available, use these apis fade-in     // progress spinner.     if (build.version.sdk_int >= build.version_codes.honeycomb_mr2) {         int shortanimtime = getresources().getinteger(                 android.r.integer.config_shortanimtime);          mloginstatusview.setvisibility(view.visible);         mloginstatusview.animate().setduration(shortanimtime)                 .alpha(show ? 1 : 0)                 .setlistener(new animatorlisteneradapter() {                     @override                     public void onanimationend(animator animation) {                         mloginstatusview.setvisibility(show ? view.visible                                 : view.gone);                     }                 });          mloginformview.setvisibility(view.visible);         mloginformview.animate().setduration(shortanimtime)                 .alpha(show ? 0 : 1)                 .setlistener(new animatorlisteneradapter() {                     @override                     public void onanimationend(animator animation) {                         mloginformview.setvisibility(show ? view.gone                                 : view.visible);                     }                 });     } else {         // viewpropertyanimator apis not available, show         // , hide relevant ui components.         mloginstatusview.setvisibility(show ? view.visible : view.gone);         mloginformview.setvisibility(show ? view.gone : view.visible);     } }  /**  * represents asynchronous login/registration task used authenticate  * user.  */ public class userlogintask extends asynctask<void, void, boolean> {     @override     protected boolean doinbackground(void... params) {         // todo: attempt authentication against network service.          try {             // simulate network access.             thread.sleep(2000);         } catch (interruptedexception e) {             return false;         }          (string credential : dummy_credentials) {             string[] pieces = credential.split(":");             if (pieces[0].equals(memail)) {                 // account exists, return true if password matches.                 return pieces[1].equals(mpassword);             }         }          // todo: register new account here.         return true;     }      @override     protected void onpostexecute(final boolean success) {         mauthtask = null;         showprogress(false);          if (success) {             finish();         } else {             mpasswordview                     .seterror(getstring(r.string.error_incorrect_password));             mpasswordview.requestfocus();         }     }      @override     protected void oncancelled() {         mauthtask = null;         showprogress(false);     } } 

i think possible scenario mainactivity's onresume called twice, assume start loginactivity in mainactivity's oncreate:

1. mainactivity created , loginactivity launched. mainactivity still continues lifecycle - onresume called (and onpause right after etc..)...
2. when finish loginactivity, mainactivity resumed again - onresume called second time.

you can consider saving boolean value (or whole dialog) preserve showing dialog second time, or can change workflow mainactivity started after successful login.