饼图未显示在android中

Question

我想要显示饼图。为此，我有以下代码：

public class Piechart extends Activity
{

  GraphicalView mChartView = null;
  private DefaultRenderer mRenderer = new DefaultRenderer();
  private CategorySeries mSeries = new CategorySeries("Expenses");
  private static int[] COLORS = new int[]{    Color.GREEN, Color.BLUE, Color.MAGENTA, Color.YELLOW, Color.RED, Color.DKGRAY, Color.BLACK};

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

    Cursor cursor; 
    int count = cursor.getCount();
    double[] values = new double[count];
    String[] categoryNames = new String[count];
    for(int i = 0; i < count; i++) 
    {   
        cursor.moveToNext();  
        values[i] = cursor.getDouble(1);
        categoryNames[i] = cursor.getString(0);
    }
    int i = 0;
    mSeries.add(categoryNames[i], values[i]);
    SimpleSeriesRenderer renderer = new SimpleSeriesRenderer();
    renderer.setColor(COLORS[(mSeries.getItemCount() - 1) % COLORS.length]);
    renderer.setDisplayChartValues(true);
    mRenderer.addSeriesRenderer(renderer);
    i++;
    mChartView = ChartFactory.getPieChartView(this, mSeries, mRenderer);

    RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
    mChartView.setLayoutParams(params);
    RelativeLayout layout = (RelativeLayout) findViewById(R.id.chartsRelativeLayout);
    layout.addView(mChartView);
  }

但是在下面的代码中我有一个错误。错误是“方法setDisplayChartValues（boolean）未定义类型SimpleSeriesRenderer”。

 renderer.setDisplayChartValues(true);

我正在关注此链接中的教程。 http://mukeshsoni.wordpress.com/2012/09/18/how-to-setup-achartengine-within-an-activity/

你能帮帮我吗？