Question

I want to pass data from my database DatabaseBon to a ListView. I want to do this without using a ListViewActivity.

I have found out that I should use cursorAdapter for this, but is there some other way(without ListViewActivity)? I implemented CursorAdapter but got a Null Pointer Exception.

My Activity looks like:

      public class BlackNumbersBlockDb extends Activity {
        String TAG;
       @Override
   protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.blocknumbersdb);
    @SuppressWarnings("unused")
    Button imBT= (Button)findViewById(R.id.importBL);
    DataBaseBON info= new DataBaseBON(this);
    info.open();
    Cursor cursor=info.getcursor();
    startManagingCursor(cursor);
    ContactCursorAdapter adapter = new ContactCursorAdapter(null, cursor);
    ListView contactLV = (ListView) findViewById(R.id.listviewblDB);
    contactLV.setAdapter(adapter);
    info.close();
        imBT.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Intent i= new Intent ("android.intent.action.IMPORTM");
            startActivity(i);   
        }
    });

My cursoradapter looks like:

            import vahid.engineer.com.DataBaseBON
            import android.content.Context;
            import android.database.Cursor;
            import android.view.LayoutInflater;
    public class ContactCursorAdapter extends CursorAdapter  {
  public ContactCursorAdapter(Context context, Cursor c) {  
    super(context, c);
}

@Override
public void bindView(View view, Context context, Cursor cursor) {
    TextView name = (TextView)view.findViewById(R.id.blacklistDB1);
    name.setText(cursor.getString(cursor.getColumnIndex(DataBaseBON.N_NAME)));
    TextView phone = (TextView)view.findViewById(R.id.blacklistDB2); 
    phone.setText(cursor.getString(cursor.getColumnIndex(DataBaseBON.KEY_NUMBER)));}

@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
    LayoutInflater inflater = LayoutInflater.from(context);
    View v = inflater.inflate(R.layout.lv, parent, false);
    bindView(v, context, cursor);
    return v;

My Xml File (block or not) is looks like

   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:orientation="vertical" >

  <ListView
      android:id="@+id/listviewblDB"
      android:layout_width="match_parent"
      android:layout_height="499dp"
      android:layout_weight="0.72" >
  </ListView>

  <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="129dp"
    android:gravity="bottom|center_horizontal|fill|top"
    android:orientation="horizontal" >

    <Button
        android:id="@+id/importBL"
        android:layout_width="100dp"
        android:layout_height="90dp"
        android:layout_marginLeft="10sp"
        android:layout_marginTop="20sp"
        android:ems="10"
        android:text="Import"
        android:textSize="20sp"/>

    </LinearLayout>

My xml file LV looks like :

            <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:orientation="vertical" >

  <TextView
          android:id="@+id/blacklistDB1"
          android:layout_width="33dp"
          android:layout_height="wrap_content"
          android:text="Large Text"
          />
   <TextView
        android:id="@+id/blacklistDB2"
        android:layout_width="19dp"
        android:layout_height="wrap_content"
        android:text="Large Text"
        />
   </LinearLayout>

My errors looks like

    FATAL EXCEPTION: main
    java.lang.NullPointerException
at android.view.LayoutInflater.from(LayoutInflater.java:171)
at vahid.engineer.com.ContactCursorAdapter.newView
at android.widget.CursorAdapter.getView(CursorAdapter.java:182)
at android.widget.AbsListView.obtainView(AbsListView.java:1315)
at android.widget.ListView.makeAndAddView(ListView.java:1727)
    at android.widget.ListView.fillDown(ListView.java:652)
at android.widget.ListView.fillFromTop(ListView.java:709)
at android.widget.ListView.layoutChildren(ListView.java:1580)
at android.widget.AbsListView.onLayout(AbsListView.java:1147)
at android.view.View.layout(View.java:7035)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:
at android.widget.LinearLayout.onLayout(LinearLayout.java:1042)
at android.view.View.layout(View.java:7035)

Answer 1

ContactCursorAdapter adapter = new ContactCursorAdapter(null, cursor);

that looks it’d have something to do with it. that parameter calls for your activity’s context, not null. You did it well for your database instantiation. The following should work.

ContactCursorAdapter adapter = new ContactCursorAdapter(BlackNumbersBlockDb.this, cursor);