public class Db1 extends ListActivity {
 static final String COL1="line";
 final Class[] classNames = {test.class, test2.class, test3.class};
 
 private SimpleCursorAdapter adapter;
 private TextView text;
 private EditText edit;
 public DBAdapter db;
   
 /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        db = new DBAdapter(this);
        db.open();
        
        text = (TextView)findViewById(R.id.text);
        edit = (EditText)findViewById(R.id.edit);
        
        ((Button)findViewById(R.id.add)).setOnClickListener(listener);
        ((Button)findViewById(R.id.del)).setOnClickListener(listener);
        ((Button)findViewById(R.id.detail)).setOnClickListener(listener);
        setEnabled(false);
    }
    
    protected void onResume() {
     super.onResume();
     
     Cursor c = db.fetchAllMemo();
     startManagingCursor(c);
     
     String[] from = new String[] { BaseColumns._ID, COL1 };
     int[] to = new int[] {R.id.id, R.id.memo};
     
     adapter = new SimpleCursorAdapter(
       this, R.layout.row, c, from, to);
     setListAdapter(adapter);
    }
    
    protected void onPause() {
     super.onPause();
     db.close();
    }
   
    protected void onListItemClick(ListView l, View v, int position, long id) {
     super.onListItemClick(l, v, position, id);
     
     TextView t = (TextView)v.findViewById(R.id.memo);
     edit.setText(t.getText());
     text.setText(Long.toString(id));
     setEnabled(true);
      //Intent intent = new Intent(Db1.this, classNames[position]);
      //startActivity(intent); 
    }    
    
    private void setEnabled(boolean enabled) {
     ((Button)findViewById(R.id.del)).setEnabled(enabled);
     ((Button)findViewById(R.id.detail)).setEnabled(enabled);
    }
    
    Button.OnClickListener listener = new View.OnClickListener() {
  @Override
  public void onClick(View v) {
   String id = text.getText().toString();
   String str = edit.getText().toString();
   
   switch(v.getId()) {
   case R.id.del:
    db.delMemo(id);
    break;
   case R.id.detail:
    //Intent intent = new Intent(Db1.this, classNames[]);
       //startActivity(intent);  
    if(str.length() !=0)
     db.modMemo(id, str);
    else
     db.delMemo(id);
    break;
   case R.id.add:
    if(str.length() !=0)
     db.addMemo(str);
    break;
   default:
    Toast.makeText(getBaseContext(), "Error!", Toast.LENGTH_LONG).show();
   }
   
   text.setText("");
   edit.setText("");
   setEnabled(false);
   
   Cursor c = db.fetchAllMemo();
   startManagingCursor(c);
   adapter.changeCursor(c);
   
  }
 };
    
}