android activity - Binary XML file line #11: Error inflating class fragment -

i getting 2 errors in code.

caused by: java.lang.illegalstateexception: fragment com.example.dfoley.write_to_file.topfragment did not create view.

caused by: android.view.inflateexception: binary xml file line #11: error inflating class fragment both pointing line mainactivity.java:21 following setcontentview(r.layout.activity_main);

bottomfragment

package com.example.dfoley.write_to_file; import android.app.listfragment; import android.os.bundle; import android.widget.arrayadapter;  import java.util.arraylist;  public class bottomfragment extends listfragment {     private arrayadapter<stateuser> adapter;      @override     public void onactivitycreated(bundle saveinstancestate){         arraylist<stateuser> flight = maincontoller.getinstance().getflights();         this.adapter = new arrayadapter<stateuser>(getactivity(), android.r.layout.simple_list_item_1, flight);         setlistadapter(this.adapter);         super.onactivitycreated(saveinstancestate);     }     public void refreshlist(){         this.adapter.notifydatasetchanged();     } } 

top fragment

package com.example.dfoley.write_to_file;  import android.app.activity; import android.app.fragment; import android.content.context; import android.os.bundle; import.android.util.log; import android.view.view; import.android.widget.button; import android.widget.edittext;  import java.io.ioexception;  import java.io.outputstreamwriter;    public class topfragment extends fragment{     private flightsearcher searcher;     edittext text1;      public interface flightsearcher {         public void refreshflightlist();     }      @override     public void onattach(activity activity) {         searcher = (flightsearcher) activity;         super.onattach(activity);     }      @override     public void onactivitycreated(bundle savedinstancestate){         setuplisteners();         super.onactivitycreated(savedinstancestate);     }      public void setuplisteners() {         button adduser = (button)getactivity().findviewbyid(r.id.button);         adduser.setonclicklistener(new view.onclicklistener() {             @override             public void onclick(view v) {                 writetofile();                 searcher.refreshflightlist();             }         });     }      private void writetofile() {         text1=(edittext)getactivity().findviewbyid(r.id.edittext);         string addusers = text1.gettext().tostring();         try {             outputstreamwriter outputstreamwriter = new outputstreamwriter(getactivity().openfileoutput("userlist", context.mode_private));             outputstreamwriter.write(addusers);             outputstreamwriter.close();         }         catch (ioexception e) {             log.e("exception", "file write failed: " + e.tostring());         }     } } 

main activity

package com.example.dfoley.write_to_file;  import android.app.fragmentmanager; import android.os.bundle; import android.support.v4.app.fragmentactivity; import android.view.menu; import android.view.menuitem;  public class mainactivity extends fragmentactivity implements topfragment.flightsearcher{      public void refreshflightlist() {         fragmentmanager mgr = getfragmentmanager();         bottomfragment bottomfragmentref =(bottomfragment) mgr.findfragmentbyid(r.id.bottom_fragment);         bottomfragmentref.refreshlist();     }      @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);     }      @override     public boolean oncreateoptionsmenu(menu menu) {         // inflate menu; adds items action bar if present.         getmenuinflater().inflate(r.menu.menu_main, menu);         return true;     }      @override     public boolean onoptionsitemselected(menuitem item) {         // handle action bar item clicks here. action bar         // automatically handle clicks on home/up button, long         // specify parent activity in androidmanifest.xml.         int id = item.getitemid();          //noinspection simplifiableifstatement         if (id == r.id.action_settings) {             return true;         }         return super.onoptionsitemselected(item);     } } 

activiy_main.xml

<relativelayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingleft="@dimen/activity_horizontal_margin" android:paddingright="@dimen/activity_horizontal_margin" android:paddingtop="@dimen/activity_vertical_margin" android:paddingbottom="@dimen/activity_vertical_margin" tools:context=".mainactivity">  <fragment     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:name="com.example.dfoley.write_to_file.topfragment"     android:id="@+id/top_fragment"     android:layout_weight="1"     android:layout_alignparenttop="true"     android:layout_alignparentleft="true"     android:layout_alignparentstart="true"     tools:layout="@layout/topfragment" />  <fragment     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:name="com.example.dfoley.write_to_file.bottomfragment"     android:id="@+id/bottom_fragment"     android:layout_weight="1"     android:layout_below="@+id/top_fragment"     android:layout_alignparentleft="true"     android:layout_alignparentstart="true"     tools:layout="@layout/bottomfragment" /> 

for both of fragments, not telling how create view. see using tools:layout tag, according tools doc, hint designer; not inflate layout:

"this attribute typically set in tag , used record layout want see rendered @ designtime (at runtime, determined actions of fragment class listed tag)."

thus need override oncreateview, inflate view hierarchy, , return that:

@override public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) {     return inflater.inflate(r.layout.topfragment, container, false); }