sqlite - Android: ListView Load gives Null Pointer Exception -

i'm trying data sqlite listview followed example in answer in url make listview sqlite database

the customcursoradapter going

    public class customcursoradapter extends simplecursoradapter  {     private int layout;      private layoutinflater inflater;     private context context;      public customcursoradapter (context context, int layout, cursor c, string[] from, int[] to) {         super(context, layout, c, from, to);         this.layout = layout;         this.context = context;         inflater = layoutinflater.from(context);      }       @override     public view newview(context context, cursor cursor, viewgroup parent) {          view v = inflater.inflate(r.layout.topics, parent, false);          return v;     }      @override     public void bindview(view v, context context, cursor c) {                 //1 column you're getting data         string name = c.getstring(1);         /**          * next set name of entry.          */         textview name_text = (textview) v.findviewbyid(r.id.listlabel);         if (name_text != null) {             name_text.settext(name);         }        } } 

but oncreate have code

listview listview = (listview)findviewbyid(r.layout.topics);     connecttodb();     = new string[] { "topictitle" };     = new int[] { r.id.listlabel };      customcursoradapter adapter = new customcursoradapter(this,             r.layout.topics, cursor, from, to);     listview.setadapter(adapter); 

with xml follows

    <?xml version="1.0" encoding="utf-8"?>  <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:padding="5dp" >      <imageview         android:id="@+id/listlogo"         android:layout_width="50dp"         android:layout_height="50dp"         android:layout_marginleft="5dp"         android:layout_marginright="20dp"         android:layout_margintop="5dp"          >     </imageview>      <textview         android:id="@+id/listlabel"         android:layout_width="250dp"         android:layout_height="wrap_content"         android:text="@+id/label"         android:textsize="15sp" >     </textview>  </linearlayout> 

the problem .. listview null!! .. don't know why!!

you refering layout topics. should have listview defined in xml id. in activity oncreate() after setcontentview(r.layout.topics), fins id of listview , set adapter list.

in xml topics.xml

<?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical"  android:background="#0095ff">    <listview android:id="@+id/list"     android:layout_width="fill_parent"     android:layout_height="100dp"      android:id="@+id/lv">    </listview>     // other ui elements </linearlayout> 

then in activity oncreate()

   setcontentview(r.layout.topics);    listview listview = (listview)findviewbyid(r.id.lv);    connecttodb();    = new string[] { "topictitle" };    = new int[] { r.id.listlabel };      customcursoradapter adapter = new customcursoradapter(this,         r.layout.topics, cursor, from, to);     listview.setadapter(adapter); 

from discussion in chat

edit:

define main.xml

<?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical"  android:background="#0095ff">  <listview android:id="@+id/list" android:layout_width="fill_parent"   android:layout_height="0dip" android:focusableintouchmode="false" android:listselector="@android:color/transparent" android:layout_weight="2" android:headerdividersenabled="false" android:footerdividersenabled="false" android:dividerheight="8dp"  android:divider="#000000"  android:cachecolorhint="#000000" android:drawselectorontop="false"> </listview> </linearlayout> 

in activivity

 public class mainactivity extends activity {   listview lv;  customcursoradapter cus;  @override  public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.main);     lv = (listview) findviewbyid(r.id.list);     cus= new customcursoradapter(parameters);     lv.setadapter(cus);   }  } 

define customcursor adapter inflate custom layout. set image image view , text textview.