title: android call log
body: <p>With the following codes, the call log displayed is empty.Why is that soo??</p>
  
  <pre><code>package fypj.c;
  
  import java.security.Provider;
  import java.util.ArrayList;   
  import android.app.Activity;
  import android.app.ListActivity;
  import android.database.Cursor;
  import android.net.Uri;
  import android.os.Bundle;
  import android.provider.CallLog;
  import android.provider.ContactsContract;
  import android.provider.ContactsContract.Data;
  import android.provider.ContactsContract.CommonDataKinds.Phone;
  import android.widget.ListAdapter;
  import android.widget.ListView;
  import android.widget.SimpleCursorAdapter;
  import android.widget.TextView;
  
  public class c extends ListActivity {
      private SimpleCursorAdapter myAdapter; 
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.main);   
  
          String[] column = new String[] {android.provider.CallLog.Calls.CACHED_NAME, android.provider.CallLog.Calls.DURATION, android.provider.CallLog.Calls.TYPE};         
          int[] names = new int[] {R.id.CLName, R.id.CLDuration, R.id.CLType};         
          myAdapter = new SimpleCursorAdapter(this,android.R.layout.simple_list_item_2, cursor, column, names);         
          setListAdapter(myAdapter);  
      }
  }
  </code></pre>
  
  <hr>
  
  <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;ListView
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:id="@android:id/list"
      /&gt;
      &lt;TextView  
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
  
      android:id="@+id/CLName"
      /&gt;
      &lt;TextView  
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
  
      android:id="@+id/CLType"
      /&gt;
      &lt;TextView  
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
  
      android:id="@+id/CLDuration"
      /&gt;
  &lt;/LinearLayout&gt;
  </code></pre>