pie chart not displayed in my application ,am using achartengine library for graph?

Am developing one apps in this i have to display pie chart , Am importing achartengine lib into my apps .the demo version of achartengine work fine it show the graph .But wen i use that into my apps nothing will displaying.anybody help me to solve this problem.

This is my code:

Main Activity:

public class HomeScreenPage extends Activity {
    public void onCreate(Bundle savedInstanceState)
    {
    super.onCreate(savedInstanceState);
 开发者_开发知识库   setContentView(R.layout.homescreenpage);

   PieChart achartIntent = new PieChart();
    achartIntent.execute(this);
    }

Piechart class :

import org.achartengine.ChartFactory;
import org.achartengine.model.CategorySeries;
import org.achartengine.renderer.DefaultRenderer;
import org.achartengine.renderer.SimpleSeriesRenderer;

import android.content.Context;
import android.content.Intent;
import android.graphics.Color;

public class PieChart {
    public Intent execute(Context context) {
        double[] values = new double[] {12, 14, 11, 10,2};
        int[] colors = new int[] {Color.BLUE, Color.GREEN, Color.MAGENTA, Color.YELLOW, Color.CYAN};
        DefaultRenderer renderer = buildCategoryRenderer(colors);
        renderer.setLabelsTextSize(10);
        return ChartFactory.getPieChartIntent(context, buildCategoryDataset("Project budget", values), renderer);
      }
    protected DefaultRenderer buildCategoryRenderer(int[] colors) {
        DefaultRenderer renderer = new DefaultRenderer();
        for (int color : colors) {
          SimpleSeriesRenderer r = new SimpleSeriesRenderer();
          r.setColor(color);
          renderer.addSeriesRenderer(r);
        }
        return renderer;
      }
    protected CategorySeries buildCategoryDataset(String title, double[] values) {
        CategorySeries series = new CategorySeries(title);
        int k = 0;
        for (double value : values) {
          series.add("Project " + ++k, value);
        }

        return series;
      }
}

Did you do all this

1:on your onCreate()

Intent achartIntent = new PieChart().execute(this);
    startActivity(achartIntent);

2: added below line in AndroidManifest.xml

<activity android:name="org.achartengine.GraphicalActivity">

3:Added the achart.*.jar as a reference library in your project's build path

You better start the activity after used .execute function in main, like this: startActivity(new PieChart().execute(this));