vb.net - Back button closing app instead of going back on Windows Phone 8.1 -

i've created simple windows phone 8.1 app in visual studio 2013 , added 2 basic pages, along code navigate second screen when button on first screen clicked. going second screen works fine, when hardware button pressed, app closes. want app go first page when button pressed.

i have followed instructions in navigationhelper.vb , added sub new() initialization commands, button still not work. how can pressing work correctly? in advance.

here code:

basicpage1.xaml.vb:

imports app1.common  public notinheritable class basicpage1     inherits page      private withevents _navigationhelper new navigationhelper(me)     private readonly _defaultviewmodel new observabledictionary()      public readonly property navigationhelper navigationhelper                     return _navigationhelper         end     end property      sub new()          initializecomponent()          me._navigationhelper = new common.navigationhelper(me)         addhandler me._navigationhelper.loadstate, addressof navigationhelper_loadstate         addhandler me._navigationhelper.savestate, addressof navigationhelper_savestate     end sub      public readonly property defaultviewmodel observabledictionary                     return _defaultviewmodel         end     end property      private sub navigationhelper_loadstate(sender object, e loadstateeventargs) handles _navigationhelper.loadstate     end sub      private sub navigationhelper_savestate(sender object, e savestateeventargs) handles _navigationhelper.savestate     end sub  #region "navigationhelper registration"      protected overrides sub onnavigatedto(e navigationeventargs)         _navigationhelper.onnavigatedto(e)     end sub      protected overrides sub onnavigatedfrom(e navigationeventargs)         _navigationhelper.onnavigatedfrom(e)     end sub  #end region      private sub button_click(sender object, e routedeventargs) handles button.click         frame.navigate(gettype(basicpage2))     end sub end class 

basicpage2.xaml.vb:

imports app1.common  public notinheritable class basicpage2     inherits page      private withevents _navigationhelper new navigationhelper(me)     private readonly _defaultviewmodel new observabledictionary()      public readonly property navigationhelper navigationhelper                     return _navigationhelper         end     end property      sub new()          initializecomponent()          me._navigationhelper = new common.navigationhelper(me)         addhandler me._navigationhelper.loadstate, addressof navigationhelper_loadstate         addhandler me._navigationhelper.savestate, addressof navigationhelper_savestate     end sub      public readonly property defaultviewmodel observabledictionary                     return _defaultviewmodel         end     end property      private sub navigationhelper_loadstate(sender object, e loadstateeventargs) handles _navigationhelper.loadstate     end sub      private sub navigationhelper_savestate(sender object, e savestateeventargs) handles _navigationhelper.savestate     end sub  #region "navigationhelper registration"      protected overrides sub onnavigatedto(e navigationeventargs)         _navigationhelper.onnavigatedto(e)     end sub      protected overrides sub onnavigatedfrom(e navigationeventargs)         _navigationhelper.onnavigatedfrom(e)     end sub  #end region  end class 

the full solution here: https://github.com/orangeflash81/simplewpapp

i fixed problem myself adding event handler using addhandler , using frame.navigate go first page. added code:

sub new()     addhandler hardwarebuttons.backpressed, addressof backpressed end sub  sub backpressed(sender object, e backpressedeventargs)     e.handled = true     frame.navigate(gettype(basicpage1)) end sub