java - AchartEngine TemperatureChart 带有单（一个）折线图线

Question

我遇到了一些问题，如果我只有一条图表线，如果我尝试显示一条图表线，那么图表线将不可见。就像显示任何行的最小值是两个。这是我的代码：

package com.achartengine.chart;
import static com.CommonUtilities.DEBUG;
import static com.CommonUtilities.TAG;

import java.util.ArrayList;

import org.achartengine.ChartFactory;
import org.achartengine.chart.BarChart.Type;
import org.achartengine.model.RangeCategorySeries;
import org.achartengine.model.XYMultipleSeriesDataset;
import org.achartengine.renderer.SimpleSeriesRenderer;
import org.achartengine.renderer.XYMultipleSeriesRenderer;

import com.work;
import com.workSummary;
import com.worksDataSource;
import com.worksSummaryDataSource;

import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.Paint.Align;
import android.util.Log;

/**
 * Temperature demo range chart.
 */
public class TemperatureChart extends AbstractDemoChart {

  /**
   * Returns the chart name.
   * 
   * @return the chart name
   */
  public String getName() {
    return "Temperature range chart";
  }

  /**
   * Returns the chart description.
   * 
   * @return the chart description
   */
  public String getDesc() {
    return "The monthly temperature (vertical range chart)";
  }

  /**
   * Executes the chart demo.
   * 
   * @param context the context
   * @return the built intent
   */
  public Intent execute(Context context) {
      if (DEBUG) Log.i(TAG, "TemperatureChart Intent execute");


        worksSummaryDataSource worksSummaryDataSource;

        worksSummaryDataSource = new worksSummaryDataSource(context);
        worksSummaryDataSource.open();

        ArrayList<workSummary> workSummaries = new ArrayList<workSummary>();
        workSummaries = worksSummaryDataSource.getAllworksSummary();

          if (DEBUG) Log.i(TAG, "TemperatureChart Intent execute got workSummaries");



    XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
    RangeCategorySeries series = new RangeCategorySeries("works");

    int[] colors = new int[] { Color.CYAN };
    XYMultipleSeriesRenderer renderer = buildBarRenderer(colors);

    worksDataSource datasource = new worksDataSource(context);
    datasource.open();

    work work = new work();
    worksDataSource worksDataSource = new worksDataSource(context);
    worksDataSource.open();


    int w = 0;
    if (DEBUG) Log.i(TAG, "workSummaries.size(): "+workSummaries.size());
    for (int i = 0; i < workSummaries.size(); i++) {
      if (DEBUG) Log.i(TAG, "TemperatureChart Intent execute workSummaries id: "+String.valueOf(workSummaries.get(i).work_id));
          for (int j = 0; j < workSummaries.get(i).summary.size(); j++) {
              w++;
              Double  down = workSummaries.get(i).summary.get(j).uptime - 100;
              Double  up = workSummaries.get(i).summary.get(j).uptime;
            series.add(down.intValue(), up.intValue());

            work = worksDataSource.getByworkId(String.valueOf(workSummaries.get(i).work_id));

            renderer.addXTextLabel(w, work.getTitle() + " - " + workSummaries.get(i).summary.get(j).service_name);
              if (DEBUG) Log.i(TAG, "TemperatureChart Intent execute workSummaries service_name: "+workSummaries.get(i).summary.get(j).service_name);
              if (DEBUG) Log.i(TAG, "TemperatureChart Intent execute workSummaries result: "+down +" "+ up);
          }
    }
    if(w == 1){
        series.add(0, 0);
    }
    worksDataSource.close();

    dataset.addSeries(series.toXYSeries());
//    setChartSettings(renderer, title, xTitle, yTitle, xMin, xMax, yMin, yMax, axesColor, labelsColor)
    setChartSettings(renderer, "Daily works Report", "", "Percentage", 0.5, 12.5, -100, 100, Color.GRAY, Color.LTGRAY);

    renderer.setBarSpacing(0.5);

    renderer.setXLabels(0);
    renderer.setYLabels(10);

    renderer.setXLabelsAngle(-55);
    renderer.setXLabelsAlign(Align.RIGHT);

    renderer.setMargins(new int[] {30, 70, 220, 10});

    renderer.setYLabelsAlign(Align.RIGHT);

    SimpleSeriesRenderer r = renderer.getSeriesRendererAt(0);

    r.setDisplayChartValues(false); //if true: display the Y values right above the chart line

    r.setChartValuesTextSize(12);
    r.setChartValuesSpacing(3);
    r.setGradientEnabled(true);
    r.setGradientStart(-20, Color.BLUE);
    r.setGradientStop(20, Color.GREEN);

    if (DEBUG) Log.i(TAG, "TemperatureChart Intent execute end");
    return ChartFactory.getRangeBarChartIntent(context, dataset, renderer, Type.DEFAULT, "Uptime/ Downtime");
  }

}

我正在使用作为解决方案：

    if(w == 1){
        series.add(0, 0);
    }

还有其他更好的方法吗