android - error RecyclerView: No adapter attached; skipping layout when running program -

i have tried answer @ stackoverflow relate problem. wanna show data firebase in imageview , textview. there's error recyclerview: no adapter attached; skipping layout. coding :

menumanajemenkendaraanfragment.java

public class menumanajemenkendaraanfragment extends fragment {  private recyclerview recyclerview; private menumanajemenkendaraanadapter adapter; private databasereference mdatabase; //private progressdialog progressdialog; private list<datakendaraan> datakendaraan;   @override public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) {     getactivity().settitle("manajemen kendaraan");     view v = inflater.inflate(r.layout.fragment_menu_manajemen_kendaraan, container, false);     floatingactionbutton fab_tambah_kendaraan = (floatingactionbutton) v.findviewbyid(r.id.fab);      mdatabase = firebasedatabase.getinstance().getreference();      recyclerview = (recyclerview) v.findviewbyid(r.id.listviewkendaraan);     recyclerview.sethasfixedsize(true);      final fragmentactivity c = getactivity();     linearlayoutmanager layoutmanager = new linearlayoutmanager(c);     recyclerview.setlayoutmanager(layoutmanager);      datakendaraan = new arraylist<>();     mdatabase = firebasedatabase.getinstance().getreference(constants.database_path_uploads);      mdatabase.addvalueeventlistener(new valueeventlistener() {         @override         public void ondatachange(datasnapshot datasnapshot) {                 //dismissing progress dialog                  //iterating through values in database                 (datasnapshot postsnapshot : datasnapshot.getchildren()) {                     datakendaraan upload = postsnapshot.getvalue(datakendaraan.class);                     datakendaraan.add(upload);                 }             adapter = new menumanajemenkendaraanadapter(getactivity(), datakendaraan);             //adding adapter recyclerview             recyclerview.setadapter(adapter);         } 

fragment_menu_manajemen_kendaraan.xml

<framelayout 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.support.v7.widget.recyclerview     android:layout_width="match_parent"     android:layout_height="match_parent"     android:layout_alignparenttop="true"     android:cliptopadding="false"     android:padding="5dp"     android:scrollbars="vertical"     android:id="@+id/listviewkendaraan"> </android.support.v7.widget.recyclerview>  <android.support.design.widget.floatingactionbutton     android:id="@+id/fab"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_margin="16dp"     android:clickable="true"     app:fabsize="normal"     android:src="@drawable/ic_add_fab"     android:layout_gravity="end|bottom"/>  </framelayout> 

menumanajemenkendraanadapter.java

public class menumanajemenkendaraanadapter extends recyclerview.adapter<menumanajemenkendaraanadapter.viewholder> {  private context context; private list<datakendaraan> datakendaraan;  public menumanajemenkendaraanadapter(context context, list<datakendaraan> datakendaraan) {     this.datakendaraan = datakendaraan;     this.context = context; }    @override public viewholder oncreateviewholder(viewgroup parent, int viewtype) {     view v = layoutinflater.from(parent.getcontext())             .inflate(r.layout.adapter_menu_manajemen_kendaraan, parent, false);     viewholder viewholder = new viewholder(v);     return viewholder; }  @override public void onbindviewholder(viewholder holder, int position) {     datakendaraan data = datakendaraan.get(position);       holder.tipekendaraan.settext(data.gettipekendaraan());     glide.with(context).load(data.geturifotokendaraan()).into(holder.fotokendaraan);   }  @override public int getitemcount() {     return datakendaraan.size(); }  class viewholder extends recyclerview.viewholder {      public textview tipekendaraan;     public imageview fotokendaraan;      public viewholder(view itemview) {         super(itemview);          tipekendaraan = (textview)itemview.findviewbyid(r.id.tipe_kendaraan);      } } 

adapter_menu_manajemen_kendaraan.xml

<android.support.v7.widget.cardview xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="90dp" android:layout_margin="5dp"> <framelayout xmlns:android="http://schemas.android.com/apk/res/android"     android:id="@+id/fragment_frame"     android:layout_width="match_parent"     android:layout_height="match_parent"> </framelayout>  <linearlayout     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:padding="10dp">  <imageview     android:id="@+id/imageviewfotokendaraan"     android:layout_width="0dp"     android:layout_height="match_parent"     android:layout_weight="2"     android:layout_marginright="10dp"/> <linearlayout     android:layout_width="0dp"     android:layout_height="match_parent"     android:orientation="vertical"     android:layout_weight="5">     <textview         android:text="tipe kendaraan"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:fontfamily="sans-serif-black"         android:textcolor="@color/coloraccent"         android:paddingbottom="2dp"         android:id="@+id/tipe_kendaraan"         android:textsize="16sp"/> </linearlayout> </linearlayout> 

thank help.

 view v = layoutinflater.from(context) .inflate(r.layout.adapter_menu_manajemen_kendaraan, parent, false); viewholder viewholder = new viewholder(v); return viewholder;