How to replace an Android fragment with another fragment inside a ViewPager? -

i have view pager consisting of 4 tabs. each tab holds own fragment.

how able use fragment transaction replace fragment in tab 3 new fragment?

i've tried lot of things, have not been able come solution @ all. i've tried looking around on google , stackoverflow, no success.

i assume fragment has button put in center. clicking on it, can change layout stays under of button. content/layout of first fragment mentioned should replaced wrappera , content/layout of second 1 should replaced wrapperb. put simple red background wrappera distinguish wrapperb, wrapperb green due same reason. hope want:

public class switchingfragment extends fragment {      button switchfragsbutton;     relativelayout wrappera, wrapperb;     view rootview;      @override     public view oncreateview(layoutinflater inflater, final viewgroup container, bundle savedinstancestate) {         rootview = inflater.inflate(r.layout.layout_switch, container, false);         wrappera = (relativelayout) rootview.findviewbyid(r.id.wrappera);         wrapperb = (relativelayout) rootview.findviewbyid(r.id.wrapperb);          switchfragsbutton = (button) rootview.findviewbyid(r.id.switchfragsbutton);         switchfragsbutton.setonclicklistener(new view.onclicklistener() {             @override             public void onclick(view arg0) {                 if (wrapperb.getvisibility() == view.gone) {                     wrapperb.setvisibility(view.visible);                     // there no need change visibility of wrappera since stays behind when wrapperb visible.                     // wrappera.setvisibility(view.gone);                 }                 else {                     wrapperb.setvisibility(view.gone);                     // again, there no need.                     // wrappera.setvisibility(view.visible);                 }             }         });          return rootview;     } } 

the layout:

<?xml version="1.0" encoding="utf-8"?> <relativelayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:layout_gravity="center"     android:orientation="vertical">      <!-- content of first fragment should in "wrappera". -->     <relativelayout         android:id="@+id/wrappera"         android:layout_width="match_parent"         android:layout_height="match_parent"         android:background="@color/red"         android:visibility="visible">      </relativelayout>      <!-- content of second fragment should in "wrapperb". -->     <relativelayout         android:id="@+id/wrapperb"         android:layout_width="match_parent"         android:layout_height="match_parent"         android:background="@color/green"         android:visibility="gone">      </relativelayout>      <!-- said, assume layout switcher button stable          , should in front of switching layouts. -->     <button         android:id="@+id/switchfragsbutton"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_centerhorizontal="true"         android:layout_centervertical="true"         android:background="@color/black"         android:text="switch"         android:textsize="20sp"         android:textstyle="bold"         android:textcolor="@color/white"/>  </relativelayout> 

alternatively, can try change fragment directly notifying fragmentpageradapter described in link: replace fragment fragment inside viewpager