安卓图表引擎AChartEngine(二) - 示例源码概述和分析

首先看一下示例中类之间的关系:
[img]https://img-my.csdn.net/uploads/201206/07/1339061960_2598.jpg[/img]
1. ChartDemo这个类是整个应用程序的入口,运行之后的效果显示一个list.

2. IDemoChart接口,这个接口定义了三个方法,

getName()返回值是listitem上显示的标题;

getDesc()返回值是listitem上显示的描述内容.

excute(context)返回值是一个Intent,当点击listitem后跳转到此Intent.

3. AbstractDemoChart类是一个抽象类,实现接口IDemoChart接口,这个类中封装了构建DataSet和renderer的方法,目的快速构建我们的dataset和renderer.这个类具体提供了哪些方法呢?见下图.至于为什么要进行这样的封装看完4中ChartFactory.get***Intent()方法的参数类型后您就明白了.
[img]https://img-my.csdn.net/uploads/201206/08/1339141260_4289.jpg[/img]
AbstractChartDemo.java:

package org.achartengine.chartdemo.demo.chart;

import java.util.Date;
import java.util.List;

import org.achartengine.chart.PointStyle;
import org.achartengine.model.CategorySeries;
import org.achartengine.model.MultipleCategorySeries;
import org.achartengine.model.TimeSeries;
import org.achartengine.model.XYMultipleSeriesDataset;
import org.achartengine.model.XYSeries;
import org.achartengine.renderer.DefaultRenderer;
import org.achartengine.renderer.SimpleSeriesRenderer;
import org.achartengine.renderer.XYMultipleSeriesRenderer;
import org.achartengine.renderer.XYSeriesRenderer;

public abstract class AbstractDemoChart implements IDemoChart {

  /**
   * 构建 XYMultipleSeriesDataset.
   * 
   * @param titles 每个序列的图例
   * @param xValues X轴的坐标
   * @param yValues Y轴的坐标
   * @return XYMultipleSeriesDataset
   */
  protected XYMultipleSeriesDataset buildDataset(String[] titles, List xValues,
      List yValues) {
    XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
    addXYSeries(dataset, titles, xValues, yValues, 0);
    return dataset;
  }

  //向DataSet中添加序列.
  public void addXYSeries(XYMultipleSeriesDataset dataset, String[] titles, List xValues,
      List yValues, int scale) {
    int length = titles.length;
    for (int i = 0; i < length; i++) {
      XYSeries series = new XYSeries(titles[i], scale); //这里注意与TimeSeries区别.
      double[] xV = xValues.get(i);
      double[] yV = yValues.get(i);
      int seriesLength = xV.length;
      for (int k = 0; k < seriesLength; k++) {
        series.add(xV[k], yV[k]);
      }
      dataset.addSeries(series);
    }
  }

  /**
   * 构建XYMultipleSeriesRenderer.
   * 
   * @param colors 每个序列的颜色
   * @param styles 每个序列点的类型(可设置三角,圆点,菱形,方块等多种)
   * @return XYMultipleSeriesRenderer
   */
  protected XYMultipleSeriesRenderer buildRenderer(int[] colors, PointStyle[] styles) {
    XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer();
    setRenderer(renderer, colors, styles);
    return renderer;
  }

  protected void setRenderer(XYMultipleSeriesRenderer renderer, int[] colors, PointStyle[] styles) {
    //整个图表属性设置
	//-->start
	renderer.setAxisTitleTextSize(16);//设置轴标题文字的大小
    renderer.setChartTitleTextSize(40);//设置整个图表标题文字的大小
    renderer.setLabelsTextSize(15);//设置轴刻度文字的大小
    renderer.setLegendTextSize(15);//设置图例文字大小
    renderer.setPointSize(5f);//设置点的大小(图上显示的点的大小和图例中点的大小都会被设置)
    renderer.setMargins(new int[] { 20, 30, 15, 20 });//设置图表的外边框(上/左/下/右)
    //-->end

    //以下代码设置没个序列的颜色.
    //-->start
    int length = colors.length;
    for (int i = 0; i < length; i++) {
      XYSeriesRenderer r = new XYSeriesRenderer();
      r.setColor(colors[i]);//设置颜色
      r.setPointStyle(styles[i]);
      renderer.addSeriesRenderer(r);
    }
    //-->end
  }

  /**
   * 设置renderer的一些属性.
   * 
   * @param renderer 要设置的renderer
   * @param title 图表标题
   * @param xTitle X轴标题
   * @param yTitle Y轴标题
   * @param xMin X轴最小值
   * @param xMax X轴最大值
   * @param yMin Y轴最小值
   * @param yMax Y轴最大值
   * @param axesColor X轴颜色
   * @param labelsColor Y轴颜色
   */
  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);
  }

  /**
   * 构建和时间有关的XYMultipleSeriesDataset,这个方法与buildDataset在参数上区别是需要List作参数.
   * 
   * @param titles 序列图例
   * @param xValues X轴值
   * @param yValues Y轴值
   * @return XYMultipleSeriesDataset
   */
  protected XYMultipleSeriesDataset buildDateDataset(String[] titles, List xValues,
      List yValues) {
    XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
    int length = titles.length;
    for (int i = 0; i < length; i++) {
      TimeSeries series = new TimeSeries(titles[i]);//构建时间序列TimeSeries,
      Date[] xV = xValues.get(i);
      double[] yV = yValues.get(i);
      int seriesLength = xV.length;
      for (int k = 0; k < seriesLength; k++) {
        series.add(xV[k], yV[k]);
      }
      dataset.addSeries(series);
    }
    return dataset;
  }

  /**
   * 构建单个CategorySeries,可用于生成饼图,注意与buildMultipleCategoryDataset(构建圆环图)相区别.
   * 
   * @param titles the series titles
   * @param values the values
   * @return the category series
   */
  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;
  }

  /**
   * 构建MultipleCategorySeries,可用于构建圆环图(每个环是一个序列)
   * 
   * @param titles the series titles
   * @param values the values
   * @return the category series
   */
  protected MultipleCategorySeries buildMultipleCategoryDataset(String title,
      List titles, List values) {
    MultipleCategorySeries series = new MultipleCategorySeries(title);
    int k = 0;
    for (double[] value : values) {
      series.add(2007 + k + "", titles.get(k), value);
      k++;
    }
    return series;
  }

  /**
   * 构建DefaultRenderer.
   * 
   * @param colors 每个序列的颜色
   * @return DefaultRenderer
   */
  protected DefaultRenderer buildCategoryRenderer(int[] colors) {
    DefaultRenderer renderer = new DefaultRenderer();
    renderer.setLabelsTextSize(15);
    renderer.setLegendTextSize(15);
    renderer.setMargins(new int[] { 20, 30, 15, 0 });
    for (int color : colors) {
      SimpleSeriesRenderer r = new SimpleSeriesRenderer();
      r.setColor(color);
      renderer.addSeriesRenderer(r);
    }
    return renderer;
  }

  /**
   * 构建XYMultipleSeriesDataset,适用于柱状图.
   * 
   * @param titles 每中柱子序列的图列
   * @param values 柱子的高度值
   * @return XYMultipleSeriesDataset
   */
  protected XYMultipleSeriesDataset buildBarDataset(String[] titles, List values) {
    XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
    int length = titles.length;
    for (int i = 0; i < length; i++) {
      CategorySeries series = new CategorySeries(titles[i]);
      double[] v = values.get(i);
      int seriesLength = v.length;
      for (int k = 0; k < seriesLength; k++) {
        series.add(v[k]);
      }
      dataset.addSeries(series.toXYSeries());
    }
    return dataset;
  }

  /**
   * 构建XYMultipleSeriesRenderer,适用于柱状图.
   * 
   * @param colors 每个序列的颜色
   * @return XYMultipleSeriesRenderer
   */
  protected XYMultipleSeriesRenderer buildBarRenderer(int[] colors) {
    XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer();
    renderer.setAxisTitleTextSize(16);
    renderer.setChartTitleTextSize(20);
    renderer.setLabelsTextSize(15);
    renderer.setLegendTextSize(15);
    int length = colors.length;
    for (int i = 0; i < length; i++) {
      SimpleSeriesRenderer r = new SimpleSeriesRenderer();
      r.setColor(colors[i]);
      renderer.addSeriesRenderer(r);
    }
    return renderer;
  }

}

4. 其他的以*Chat结尾的类大都继承自AbstractDemoChart这个类实现了接口IDemoChart.我们可以重点看一下execute(context)方法,分析之后发现这个方法中构建Intent的步骤大同小异,第一步构建dataset,第二步构建renderer,第三步调用ChartFactory.get***Intent()方法或ChartFactory.get***View()方法,二者的区别在于一个返回Intent,这个intent可以启动一个特定的activity,另一个返回GraphicalView,对这个GraphicalView可以灵活设置也可以仅作为一部分显示在任何activity上.对于ChartFactory.get***Intent()上的参数activityTitle是指设置显示在activity上的标题.
[img]http://blog.csdn.net/lk_blog/article/details/7642751[/img]