java - How to change theme in app settings -

i working on app in user able pick list of color options in settings (all code shown below). when not change after settings activity. changes when leave activity(say home) , come back. believe because oncreate() not being called, problem if setcontentview() again whole app unresponsive. , if recreate() crashes because of music player (again code below). please leave answer if think work. in advance.

code: settingsactivity.java (also cant bar change on one)

    public class settingsactivity extends preferenceactivity {     @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         sharedpreferences settings = preferencemanager.getdefaultsharedpreferences(getapplicationcontext());         string themename = settings.getstring("theme", "darkblue");         int theme = mythemer.getthemeid(themename);         if(build.version.sdk_int > 20){             int themedark = mythemer.getcolorprimarydark(themename);             getwindow().setstatusbarcolor(getresources().getcolor(themedark));         }         settheme(theme);         addpreferencesfromresource(r.layout.settings_activity);          string themname = settings.getstring("theme", "darkblue");         int barcolor = mythemer.getcolorprimary(themname);          linearlayout root = (linearlayout)findviewbyid(android.r.id.list).getparent().getparent().getparent();         toolbar bar = (toolbar) layoutinflater.from(this).inflate(r.layout.settings_toolbar, root, false);         bar.setbackgroundcolor(getresources().getcolor(barcolor));         root.addview(bar, 0); // insert @ top         bar.setnavigationonclicklistener(new view.onclicklistener() {             @override             public void onclick(view v) {                 finish();             }         });     } } 

code: mainactivity.java

oncreate()

protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     settings = preferencemanager.getdefaultsharedpreferences(getapplicationcontext());     mysettheme();     setcontentview(r.layout.activity_game_over); 

settheme()

private void mysettheme(){     themename = settings.getstring("theme", "darkblue");     int theme = mythemer.getthemeid(themename);     settheme(theme);     if(build.version.sdk_int > 20){         int themedark = mythemer.getcolorprimarydark(themename);         getwindow().setstatusbarcolor(getresources().getcolor(themedark));     } } 

onresume()

public void onresume(){     super.onresume();     playmusic = settings.getboolean("playmusic", true);     if(playmusic){         backgroundmusicplayer = new backgroundmusicplayer();         backgroundmusicplayer.execute(getapplicationcontext());     } } 

onpause()

public void onpause(){     super.onpause();     if(playmusic){         backgroundmusicplayer.cancelmusic();         backgroundmusicplayer.cancel(true);     } } 

backgroundmusicplayer.java

public class backgroundmusicplayer extends asynctask<context, void, void>{      mediaplayer player;     @override     protected void doinbackground(context... params) {         player = mediaplayer.create(params[0], r.raw.background);         player.setlooping(true);         player.setvolume(50,50);         player.start();         return null;     }      public void cancelmusic(){         player.stop();         player.reset();         player.release();     } } 

just had replace finish();

intent home = new intent(getapplicationcontext(), mainactivity.class);                 startactivity(home); 

thank reading question.