android - Fragment container with Viewpager, tabs, and drawerlayout doesn't work -

i have drawerlayout, viewpager, , tablayout in activity_main.xml have 2 fragments homefragment , bookingfragment, i'm trying launch bookingfragment activity's on itemclick. have tried multiple solutions creating framelayout id container , put pager inside , user in fragment transaction , tried making empty framelayout same id , put above pager, didn't work.

here's code method i'm trying start fragment from

public void starttransaction(){         fragment newfragment = new bookingfragment();         fragmenttransaction transaction = getsupportfragmentmanager().begintransaction();         transaction.add(r.id.pager, newfragment);         transaction.addtobackstack(null);         transaction.commit();     } 

here's activity_main.xml

<android.support.v4.widget.drawerlayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     xmlns:tools="http://schemas.android.com/tools"     android:id="@+id/drawer_layout"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context="net.app.cairobus.cairobus.mainactivity">       <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"         xmlns:app="http://schemas.android.com/apk/res-auto"         xmlns:tools="http://schemas.android.com/tools"         android:layout_width="match_parent"         android:layout_height="match_parent"         android:orientation="vertical"         tools:context=".mainactivity">          <android.support.v7.widget.toolbar             android:id="@+id/app_bar"             android:layout_width="match_parent"             android:layout_height="wrap_content"             android:layout_alignparenttop="true"             android:background="?attr/colorprimary"             android:elevation="6dp"             android:minheight="?attr/actionbarsize"             android:theme="@style/themeoverlay.appcompat.dark.actionbar"             app:popuptheme="@style/themeoverlay.appcompat.light" />          <android.support.design.widget.tablayout             android:id="@+id/tab_layout"             android:layout_width="match_parent"             android:layout_height="wrap_content"             android:layout_below="@+id/app_bar"             android:background="?attr/colorprimary"             android:elevation="6dp"             android:minheight="?attr/actionbarsize"             android:theme="@style/themeoverlay.appcompat.dark.actionbar" />           <android.support.v4.view.viewpager             android:id="@+id/pager"             android:layout_width="match_parent"             android:layout_height="fill_parent"             android:layout_below="@id/tab_layout"             android:background="#fff" />       </linearlayout>      <android.support.design.widget.navigationview         android:id="@+id/main_drawer"         android:layout_width="wrap_content"         android:layout_height="match_parent"         android:layout_gravity="start"         android:background="#f2f2f2"         app:headerlayout="@layout/drawer_header"         app:itemicontint="@color/accent"         app:itemtextcolor="@color/secondary_text"         app:menu="@menu/menu_drawer" />   </android.support.v4.widget.drawerlayout> 

and here's fragment i'm trying start

public class bookingfragment extends fragment {      private static final string arg_param1 = "param1";     private static final string arg_param2 = "param2";     private string mparam1;     private string mparam2;     private onfragmentinteractionlistener mlistener;      public static bookingfragment newinstance(string param1, string param2) {         bookingfragment fragment = new bookingfragment();         bundle args = new bundle();         args.putstring(arg_param1, param1);         args.putstring(arg_param2, param2);         fragment.setarguments(args);         return fragment;     }      public bookingfragment() {}      @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         if (getarguments() != null) {             mparam1 = getarguments().getstring(arg_param1);             mparam2 = getarguments().getstring(arg_param2);         }       }      @override public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) {         return inflater.inflate(r.layout.fragment_booking, container, false);     }      public void onbuttonpressed(uri uri) {         if (mlistener != null) {             mlistener.onfragmentinteraction(uri);         }     }      @override     public void onattach(activity activity) {         super.onattach(activity);     }      @override     public void ondetach() {         super.ondetach();         mlistener = null;     }      public interface onfragmentinteractionlistener {         // todo: update argument type , name         public void onfragmentinteraction(uri uri);     }  } 

you can't programmatically add fragment viewpager. that's job of fragmentpageradapter.

so main activity has homefragment tab , bookingfragment tab. want navigate homefragment tripactivity, , navigate tripactivity bookingfragment.

to navigate homefragment tripactivity, use activity.startactivityforresult().

to navigate tripactivity bookingfragment, call activity.setresult() activity.finish(). in setresult(), can set result code means "open bookingfragment" , set other parameters need in data intent.

in mainactivity, override onactivityresult(). when receive result code bookingfragment, call setcurrentitem(page) on viewpager display bookingfragment.

if need set fields in bookingfragment, you'll need keep reference bookingfragment returned adapter.getitem() can call setters, etc.