Android 如何使用aChartEngine api制作折线图？

我正在尝试使用aChartEngine api包装一个折线图，但它不会出现，尽管我已经遵循了这些步骤。这里我给出了我的申请的完整代码

主类

public class MainActivity extends ActionBarActivity {

private GraphicalView mChart;


private String[] mMonth = new String[] {
          "Jan", "Feb" , "Mar", "Apr", "May", "Jun",

          "Jul", "Aug" };

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

        OpenChart();
    }

 private void OpenChart()
    {

     int z[]={0,1,2,3,4,5,6,7};


       int x[]={10,18,32,21,48,60,53,80};


      // Create XY Series for X Series.
     XYSeries xSeries=new XYSeries("X Series");


     //  Adding data to the X Series.
     for(int i=0;i<z.length;i++)
     {
      xSeries.add(z[i],x[i]);

     }

        // Create a Dataset to hold the XSeries.

     XYMultipleSeriesDataset dataset=new XYMultipleSeriesDataset();

      // Add X series to the Dataset.   
 dataset.addSeries(xSeries);


      // Create XYSeriesRenderer to customize XSeries

     XYSeriesRenderer Xrenderer=new XYSeriesRenderer();
     Xrenderer.setColor(Color.GREEN);
     Xrenderer.setPointStyle(PointStyle.DIAMOND);
     Xrenderer.setDisplayChartValues(true);
     Xrenderer.setLineWidth(2);
     Xrenderer.setFillPoints(true);

     // Create XYMultipleSeriesRenderer to customize the whole chart

     XYMultipleSeriesRenderer mRenderer=new XYMultipleSeriesRenderer();

     mRenderer.setChartTitle("X Vs Y Chart");
     mRenderer.setXTitle("X Values");
     mRenderer.setYTitle("Y Values");
     mRenderer.setZoomButtonsVisible(true);
     mRenderer.setXLabels(0);
     mRenderer.setPanEnabled(false);

     mRenderer.setShowGrid(true);

     mRenderer.setClickEnabled(true);

     for(int i=0;i<z.length;i++)
     {
      mRenderer.addXTextLabel(i, mMonth[i]);
     }

       // Adding the XSeriesRenderer to the MultipleRenderer. 
     mRenderer.addSeriesRenderer(Xrenderer);


     LinearLayout chart_container=(LinearLayout)findViewById(R.id.Chart_layout);

   // Creating an intent to plot line chart using dataset and multipleRenderer

     mChart=(GraphicalView)ChartFactory.getLineChartView(getBaseContext(), dataset, mRenderer);

     //  Adding click event to the Line Chart.

     mChart.setOnClickListener(new View.OnClickListener() {

   @Override
   public void onClick(View arg0) {
    // TODO Auto-generated method stub

    SeriesSelection series_selection=mChart.getCurrentSeriesAndPoint();

    if(series_selection!=null)
    {
     int series_index=series_selection.getSeriesIndex();

     String select_series="X Series";
     if(series_index==0)
     {
      select_series="X Series";
     }else
     {
      select_series="Y Series";
     }

     String month=mMonth[(int)series_selection.getXValue()];

     int amount=(int)series_selection.getValue();

     Toast.makeText(getBaseContext(), select_series+"in" + month+":"+amount, Toast.LENGTH_LONG).show();
    }
   }
  });

// Add the graphical view mChart object into the Linear layout .
     chart_container.addView(mChart);


    }



}

公共类MainActivity扩展了ActionBarActivity{
private GraphicalView mChart；
私有字符串[]mMonth=新字符串[]{
“一月”、“二月”、“三月”、“四月”、“五月”、“六月”，
“七月”、“八月”}；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
OpenChart（）；
}
私有void OpenChart（）
{
intz[]={0,1,2,3,4,5,6,7}；
int x[]={10,18,32,21,48,60,53,80}；
//为X系列创建XY系列。
XYSeries X系列=新的XYSeries（“X系列”）；
//向X系列添加数据。
对于（int i=0；我能有人帮我吗？？？我不能理解04-25 07:18:49.804:E/AndroidRuntime（1763）：java.lang.NoClassDefFoundError:org.achartengine.model.XYSeries 04-25 07:18:49.804:E/AndroidRuntime（1763）：在com.example.jj.MainActivity.OpenChart（MainActivity.java:5检查您是否正确添加了achartengine jar
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.jj.MainActivity" >

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

<LinearLayout 
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:id="@+id/Chart_layout"
    android:orientation="vertical">

</LinearLayout>

</LinearLayout>

</menu>