java - How to use webview in Android xml? -

i have created layout.xml.

    <?xml version="1.0" encoding="utf-8"?>     <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"         android:layout_width="match_parent"         android:layout_height="match_parent"         android:orientation="vertical" >          <webview             android:id="@+id/mwebview"             android:layout_width="fill_parent"             android:layout_height="fill_parent" />      </linearlayout> 

this in activity. m getting web-view can not resolved or not field , getting nullpointerexception.here code.

     @override             protected void oncreate(bundle savedinstancestate) {                 super.oncreate(savedinstancestate);                  setcontentview(r.layout.main);                 mwebview=(webview)findviewbyid(r.id.mwebview);                  new getcontactstask().execute();              } 

change java code:

setcontentview(r.layout.layout) //true 

instead of:

setcontentview(r.layout.main);  //false