android - Handling back key for navigation drawer and fragment page -

i working on app have few fragment pages have navigation drawer menu.

when on fragments page , click on key, application exit dialog working fine. when on fragment page , @ same time if click navigation menu, navigation menu top position. if click on key, application exit button coming want navigation menu should disappear first not exit dialogue box.

code onbackpressed():

public void onbackpressed()  {         final fragmentmanager fm = getsupportfragmentmanager();         if(fm.getbackstackentrycount() != 1){            super.onbackpressed();          }         else         {              alertdialog.builder alertdialogbuilder = new alertdialog.builder(this);             alertdialogbuilder.settitle("exit application?");             alertdialogbuilder                     .setmessage("click yes exit!")                     .setcancelable(false)                     .setpositivebutton("yes",                             new dialoginterface.onclicklistener() {                                 public void onclick(dialoginterface dialog, int id) {                                     movetasktoback(true);                                     android.os.process.killprocess(android.os.process.mypid());                                     system.exit(1);                                 }                             })                      .setnegativebutton("no", new dialoginterface.onclicklistener() {                         public void onclick(dialoginterface dialog, int id) {                              dialog.cancel();                         }                     });              alertdialog alertdialog = alertdialogbuilder.create();             alertdialog.show();         }     } 

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code ondraweritemclick():  private void ondraweritemclick(final int item) {         userservice userservice = new userservice(this);         switch (item) {             case test1:                 test1();                 break;             case test2:                 test2();                 break;             case logout:                 userservice.logout();                 finish();                 toast.maketext(menuactivity.this, "logout", toast.length_short).show();                 break;         }         mdrawerlayout.closedrawer(gravitycompat.start);     } 

 @override public void onbackpressed() {     drawerlayout drawer = (drawerlayout) findviewbyid(r.id.drawerlayout);     assert drawer != null;     if (drawer.isdraweropen(gravitycompat.start)) {         drawer.closedrawer(gravitycompat.start);     } else {         super.onbackpressed();     } }