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POListActivity throws NullPointerException
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  1. POListActivity throws NullPointerException
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    copied!<p>Hey guys i have a ListActivity... a very simple at that... and it keeps throwing NullPointer Exception though i have done it exactly as the Sample List7 except that i have used the Layout inflater... below is the code... Can u plz comment the error i have done here??</p> <pre><code>import java.util.Vector; import android.app.Activity; import android.app.ListActivity; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.ListView; import android.widget.TextView; import android.widget.AdapterView.OnItemSelectedListener; public class CustomList extends ListActivity implements OnItemSelectedListener{ Vector&lt;String&gt; VTitle; Vector&lt;String&gt; VDescription; TextView display; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); VTitle.addElement("First Title"); VTitle.addElement("Second Title"); VTitle.addElement("Third Title"); VTitle.addElement("Fourth Title"); VDescription.addElement("1 Description"); VDescription.addElement("2 Description"); VDescription.addElement("3 Description"); VDescription.addElement("4 Description"); display = (TextView)findViewById(R.id.display); setListAdapter(new CustomAdapter(this)); } @Override protected void onListItemClick(ListView l, View v, int position, long id) { // TODO Auto-generated method stub display.setText(VTitle.elementAt(position)); } class CustomAdapter extends BaseAdapter { protected Activity mContext; public CustomAdapter(Activity context) { mContext = context; // TODO Auto-generated constructor stub } @Override public int getCount() { // TODO Auto-generated method stub return VTitle.size(); } @Override public Object getItem(int position) { // TODO Auto-generated method stub return position; } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub View row = convertView; if(row==null) { LayoutInflater inflater = mContext.getLayoutInflater(); row = inflater.inflate(R.layout.row,null); } TextView title = (TextView)row.findViewById(R.id.title); title.setText(VTitle.elementAt(position)); TextView description = (TextView)row.findViewById(R.id.description); description.setText(VDescription.elementAt(position)); ImageView image = (ImageView)row.findViewById(R.id.image); switch(position){ case 0: image.setImageResource(R.drawable.check); break; case 1: image.setImageResource(R.drawable.dos); break; case 2: image.setImageResource(R.drawable.smily); break; case 3: image.setImageResource(R.drawable.wrong); break; } return(row); } } @Override public void onItemSelected(AdapterView parent, View v, int position, long id) { // TODO Auto-generated method stub display.setText(VTitle.elementAt(position)); } @Override public void onNothingSelected(AdapterView&lt;?&gt; arg0) { // TODO Auto-generated method stub } } </code></pre> <p>And the xmls are like this....</p> <p>"main.xml"</p> <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt; &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" &gt; &lt;TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:id = "@+id/display" android:text="something" /&gt; &lt;ListView android:id="@android:id/list" android:layout_width="fill_parent" android:drawSelectorOnTop="false" android:layout_height="0px"&gt; &lt;/ListView&gt; &lt;/LinearLayout&gt; </code></pre> <p>"row.xml"</p> <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt; &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="wrap_content" android:layout_height="wrap_content"&gt; &lt;ImageView android:id="@+id/image" android:layout_width="wrap_content" android:layout_height="wrap_content"&gt; &lt;/ImageView&gt; &lt;TextView android:text="Title" android:id="@+id/title" android:layout_width="wrap_content" android:layout_height="wrap_content"&gt; &lt;/TextView&gt; &lt;TextView android:text="description" android:id="@+id/description" android:layout_width="wrap_content" android:layout_height="wrap_content"&gt; &lt;/TextView&gt; &lt;/LinearLayout&gt; </code></pre>
 

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