Android : How to refresh or update listview using BaseAdapter?

I have been trying to refresh to refresh the listview whenever I delete the row in it.I have used BaseAdapter for listview.I am not gettting how to refresh it.I used SQLite and while refreshing I am deleting the row in DataBAse as well.

public class MainActivity extends Activity {

DataBase md ;
ImageButton ib;
ListView notelist;
int i;
ArrayList<String> titles = new ArrayList<String>();
ArrayList<String> not = new ArrayList<String>();
ArrayList<String> date = new ArrayList<String>();
ArrayList<String> time = new ArrayList<String>();

ArrayList<String> Revtitles = new ArrayList<String>();
ArrayList<String> Revnot = new ArrayList<String>();
ArrayList<String> Revdate = new ArrayList<String>();
ArrayList<String> Revtime = new ArrayList<String>();


DataAdapter  adapter;

View view;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

md = new DataBase(this);

SQLiteDatabase sd = md.getReadableDatabase();

Cursor c = sd.query(md.TABLE_NAME,null,null,null,null,null,null);

while(c.moveToNext()){



    titles.add(c.getString(0));
    not.add(c.getString(1));
    date.add(c.getString(2));
    time.add(c.getString(3));


}

for(int i=titles.size()-1;i>=0;i--){


    Revtitles.add(titles.get(i));
    Revnot.add(not.get(i));
    Revdate.add(date.get(i));
    Revtime.add(time.get(i));

}






notelist = (ListView) findViewById(R.id.listView1);
ib= (ImageButton) findViewById(R.id.imageButton1);



adapter = new DataAdapter(this);
notelist.setAdapter(adapter);
//notelist.setStackFromBottom(true);
notelist.setOnItemClickListener(new OnItemClickListener() {

    @Override
    public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
            long arg3) {
        // TODO Auto-generated method stub
        Intent i = new Intent(MainActivity.this,Show.class);

        i.putExtra("TITLE", Revtitles.get(arg2));
        i.putExtra("NOTE", Revnot.get(arg2));

        startActivity(i);
        finish();

    }
});

notelist.setOnItemLongClickListener(new OnItemLongClickListener() {

    @Override
    public boolean onItemLongClick(AdapterView<?> parent, View v,
            final int pos, long arg3) {
        // TODO Auto-generated method stub
        final String st = Revtitles.get(pos);
        String st1 = Revnot.get(pos);


        AlertDialog.Builder ad = new AlertDialog.Builder(MainActivity.this);
        ad.setMessage("Are sure you want to delete?");
        ad.setCancelable(false);
        ad.setPositiveButton("Yes", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface arg0, int arg1) {
                // TODO Auto-generated method stub

            //sd.delete(md.TABLE_NAME, md.COL_ROLLNO+"=?", new String[]{st});


            //Intent i = new Intent(MainActivity.this,MainActivity.class);
            //startActivity(i);



        ///////PROBLEM LINES///////



                SQLiteDatabase sd = md.getWritableDatabase();

                sd.delete(md.TABLE_NAME,md.COL_TITLE+"=?", new String[]{st});


            Revtitles.remove(pos);
            Revnot.remove(pos);
            Revdate.remove(pos);
            Revtime.remove(pos);



             adapter.notifyDataSetChanged();
             adapter.notifyDataSetInvalidated();

             notelist.setAdapter(adapter);



            }



        });
        ad.setNegativeButton("No", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                // TODO Auto-generated method stub
                dialog.dismiss();
            }
        });

        AlertDialog adl =ad.create();
        adl.show();
        return true;
    }


});




ib.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View arg0) {
        // TODO Auto-generated method stub
    Intent i = new Intent(MainActivity.this,Add.class);
    startActivity(i);
    finish();
    }
});



}


class DataAdapter extends BaseAdapter{

    private Context con;
    LayoutInflater lat = getLayoutInflater();


    public DataAdapter(MainActivity mainActivity) {
        // TODO Auto-generated constructor stub
    this.con=mainActivity;
    }



    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return titles.size();
    }

    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public long getItemId(int arg0) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public View getView(int position, View convo, ViewGroup arg2) {
        // TODO Auto-generated method stub
        convo = lat.inflate(R.layout.mainlist, null);

        TextView tit = (TextView)convo.findViewById(R.id.inflatetitle);
        TextView datea = (TextView)convo.findViewById(R.id.inflatedate);
        String rtitle;


        int len = Revtitles.get(position).length();
        if(len<=20){
         rtitle = Revtitles.get(position);
        }
        else{

            rtitle = Revtitles.get(position).substring(0, 20)+"...";
        }
        tit.setText(rtitle);
        datea.setText(Revdate.get(position)+"\n"+Revtime.get(position));

        view = convo;
        return convo;
    }



}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    // TODO Auto-generated method stub
    if ((keyCode == KeyEvent.KEYCODE_BACK))
    {
        finish();
    }
    return super.onKeyDown(keyCode, event);
}

}