安卓中用谷歌开源AchartEngineActivity引擎绘制柱状图、曲线图

1.简介

  AChartEngine(简称ACE)是Google的一个开源图表库(for Android)。。该项目地址位于: http://code.google.com/p/achartengine/。它功能强大,支持散点图、折线图、饼图、气泡图、柱状图、短棒图、仪表图等多种图表

2.开发步骤

1)在工程中新建一个文件夹比如lib,用于存放ACE Libraries,把achartegine-0.5.0.jar包复制到lib里面。然后把这个jar的路径添加到项目的Build Path中。

2)修改AndroidManifest.xml

  主要是加入一个:

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

3)绘制柱状图

public class main extends ListActivity {  
  private static final int SERIES_NR = 2;  
    /** Called when the activity is first created. */ 
  private ArrayList<Map<String,String>> maps = new ArrayList<Map<String,String>>();  
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super .onCreate(savedInstanceState);  
//        setContentView(R.layout.main);  
        // 加入 ListItem “ 调度查询 ”  
        HashMap<String,String> map= new HashMap<String,String>();  
        map.put( "name" , " 柱状图 " );  
        map.put( "desc" , " 显示柱状图 " );  
        maps .add(map);  
        // 构建 listView 的适配器  
        SimpleAdapter adapter= new SimpleAdapter( this , maps ,  
        android.R.layout. simple_list_item_2 , // SDK 库中提供的一个包含两个 TextView 的 layout  
        new String\[\]{ "name" , "desc" }, // maps 中的两个 key  
        new int \[\]{android.R.id. text1 ,android.R.id. text2 } // 两个 TextView 的 id        
        );  
        this .setListAdapter(adapter);  
          
    }  
    // ListItem 监听器方法  
    protected void onListItemClick(ListView l, View v, int position, long id) {  
        super .onListItemClick(l, v, position, id);  
        XYMultipleSeriesRenderer renderer = getBarDemoRenderer();  
        Intent intent = ChartFactory.getBarChartIntent ( this , getBarDemoDataset(), renderer, Type. DEFAULT );  
        startActivity(intent);  
    }  
    private XYMultipleSeriesDataset getBarDemoDataset() {  
        XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();  
        final int nr = 10;  
        Random r = new Random();  
        for ( int i = 0; i < SERIES_NR ; i++) {  
          CategorySeries series = new CategorySeries( "Demo series " + (i + 1));  
          for ( int k = 0; k < nr; k++) {  
            series.add(100 + r.nextInt() % 100);  
          }  
          dataset.addSeries(series.toXYSeries());  
        }  
        return dataset;  
      }  
    public XYMultipleSeriesRenderer getBarDemoRenderer() {  
        XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer();  
        SimpleSeriesRenderer r = new SimpleSeriesRenderer();  
        r.setColor(Color. BLUE );  
        renderer.addSeriesRenderer(r);  
        r = new SimpleSeriesRenderer();  
        r.setColor(Color. GREEN );  
        renderer.addSeriesRenderer(r);  
        setChartSettings(renderer);  
        return renderer;  
      }  
    
       private void setChartSettings(XYMultipleSeriesRenderer renderer) {  
        renderer.setChartTitle( "Chart demo" );  
        renderer.setXTitle( "x values" );  
        renderer.setYTitle( "y values" );  
        renderer.setXAxisMin(0.5);  
        renderer.setXAxisMax(10.5);  
        renderer.setYAxisMin(0);  
        renderer.setYAxisMax(210);  
      }  
}

  代码说明:在 onListItemClick 方法中,当用户点击了“显示图表”之后,构造一个intent对象,然后用startActivity发送消息到前面AndroidManifest.xml申明的那个activity( 即 GraphicalActivity )。于是图表就显示出来了。关键是intent的构造方法 ChartFactory.getBarChartIntent。

  ChartFactory提供了许多有用的工厂方法,如果你需要生成一个折线图,可以用它的 getLineChartIntent 方法。

  getBarChartIntent 方法有点复杂,需要我们准备很多参数传入。其中一个是 XYMultipleSeriesDataset 类型的对象,用于提供图表需要表示的数据集,这里我们用     getBarDemoDataset 来得到它。另外一个是 XYMultipleSeriesRenderer 类型的对象,用于提供图表展现时的一些样式,这里我们用 getBarDemoRenderer 方法来得到它。

  getLineChartIntent 方法很无聊,使用了一些随机数来作为图表数据。注意柱状图是支持多系列的,这里生成了两个系列的数据。

  getBarDemoRenderer 方法构建了一个 XYMultipleSeriesRenderer 用来设置2个系列各自的颜色,然后调用 setChartSettings 方法设置了下坐标轴样式。

4)**绘制曲线``` import java.util.ArrayList;   import java.util.List;      import org.achartengine.ChartFactory;   import org.achartengine.chart.PointStyle;   import org.achartengine.model.XYMultipleSeriesDataset;   import org.achartengine.model.XYSeries;   import org.achartengine.renderer.XYMultipleSeriesRenderer;   import org.achartengine.renderer.XYSeriesRenderer;      import android.app.Activity;   import android.graphics.Color;   import android.os.Bundle;   import android.view.View;      public class chartDemo extends Activity {                @Override       public void onCreate(Bundle savedInstanceState) {           super.onCreate(savedInstanceState);              String[] titles = new String[] { "First", "Second"};              List x = new ArrayList();           List y = new ArrayList();              x.add(new double[] { 1, 3, 5, 7, 9, 11} );           x.add(new double[] { 0, 2, 4, 6, 8, 10} );              y.add(new double[] { 3, 14, 5, 30, 20, 25});           y.add(new double[] { 18, 9, 21, 15, 10, 6});              XYMultipleSeriesDataset dataset = buildDataset(titles, x, y);              int[] colors = new int[] { Color.BLUE, Color.GREEN};           PointStyle[] styles = new PointStyle[] { PointStyle.CIRCLE, PointStyle.DIAMOND};           XYMultipleSeriesRenderer renderer = buildRenderer(colors, styles, true);              setChartSettings(renderer, "Line Chart Demo", "X", "Y", -1, 12, 0, 35 , Color.WHITE, Color.WHITE);              View chart = ChartFactory.getLineChartView(this, dataset, renderer);              setContentView(chart);       }          protected XYMultipleSeriesDataset buildDataset(String[] titles,                                                      List xValues,                                                      List yValues)       {           XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();              int length = titles.length;                  //有几条线            for (int i = 0; i < length; i++)           {               XYSeries series = new XYSeries(titles[i]);    //根据每条线的名称创建                 double[] xV = xValues.get(i);                 //获取第i条线的数据                 double[] yV = yValues.get(i);               int seriesLength = xV.length;                 //有几个点                    for (int k = 0; k < seriesLength; k++)        //每条线里有几个点                 {                   series.add(xV[k], yV[k]);               }                  dataset.addSeries(series);           }              return dataset;       }          protected XYMultipleSeriesRenderer buildRenderer(int[] colors, PointStyle[] styles, boolean fill)       {           XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer();           int length = colors.length;           for (int i = 0; i < length; i++)           {               XYSeriesRenderer r = new XYSeriesRenderer();               r.setColor(colors[i]);               r.setPointStyle(styles[i]);               r.setFillPoints(fill);               renderer.addSeriesRenderer(r);           }           return renderer;       }          protected void setChartSettings(XYMultipleSeriesRenderer renderer, String title,                                   String xTitle,String yTitle, double xMin,                                   double xMax, double yMin, double yMax,                                   int axesColor,int labelsColor)       {           renderer.setChartTitle(title);           renderer.setXTitle(xTitle);           renderer.setYTitle(yTitle);           renderer.setXAxisMin(xMin);           renderer.setXAxisMax(xMax);           renderer.setYAxisMin(yMin);           renderer.setYAxisMax(yMax);           renderer.setAxesColor(axesColor);           renderer.setLabelsColor(labelsColor);       }   }

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