java - Android Resources$NotFoundException: Resource ID #0x0 -

right trying create activity edittext , button, , below listview can dynamically add strings list. i'm getting errors trying mock activity.

here main activity.

public class mainactivity extends activity {  private connection serverconnection; private arraylist<string> listitems = new arraylist<string>(); private arrayadapter<string> adapter;  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);       listview listview = (listview) findviewbyid(r.id.list);     adapter = new arrayadapter<string>(mainactivity.this, 0, listitems);     listview.setadapter(adapter);     serverconnection = new connection(mainactivity.this);  }    @override public boolean oncreateoptionsmenu(menu menu) {     // inflate menu; adds items action bar if present.     getmenuinflater().inflate(r.menu.main, menu);     return true; }  public void displaymessage(string string) {      listitems.add(string);      adapter.notifydatasetchanged();  }  } 

here xml main activity.

<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:paddingbottom="@dimen/activity_vertical_margin" android:paddingleft="@dimen/activity_horizontal_margin" android:paddingright="@dimen/activity_horizontal_margin" android:paddingtop="@dimen/activity_vertical_margin" tools:context=".mainactivity" >  <edittext     android:id="@+id/message_entry"     android:layout_width="0dp"     android:layout_height="wrap_content"     android:layout_alignleft="@+id/list"     android:layout_toleftof="@+id/send_button"     android:layout_weight="1"     android:hint="@string/enter_message" />      <listview         android:id="@+id/list"         android:layout_width="match_parent"         android:layout_height="match_parent"         android:layout_below="@+id/message_entry"         android:paddingtop="10dp" />      <button         android:id="@+id/send_button"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_alignbottom="@+id/message_entry"         android:layout_alignright="@+id/list"         android:layout_aligntop="@+id/message_entry" />  </relativelayout> 

here other class i'm going use connecting socket.

public class connection extends thread {  private socket client;  private objectoutputstream output; private objectinputstream input;  public connection(mainactivity mainactivity) {       mainactivity.displaymessage("test1");     mainactivity.displaymessage("test2");            mainactivity.displaymessage("test3");     mainactivity.displaymessage("test4");     mainactivity.displaymessage("test5");   } } 

this line gives error

adapter = new arrayadapter<string>(mainactivity.this, 0, listitems); 

the second parameter accepts layout resourceid can populate value (string) layout.

you can use layout of android framework android.r.layout.simple_list_item_1

adapter = new arrayadapter<string>(mainactivity.this, android.r.layout.simple_list_item_1, listitems);