Question

我想从表中获取一些值并将它们存储在多线图中。当我只使用一列（胖）时，它会正确显示图形，但是当我添加另一列或两列时，它会给我一个错误说：数据集和渲染器不应为null，并且不应具有相同的系列数。你能帮我修一下这个错误吗？

  public XYMultipleSeriesDataset getFatDataset() {

    XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
    Cursor c = database.rawQuery("select * from dailystats;", null);
    float i = 1.0f;

    c.moveToFirst();
    XYSeries seriesFat = new XYSeries("Fat");
    while(!c.isAfterLast()) {
        seriesFat.add(i++, c.getDouble(2));

        c.moveToNext();
    }
    dataset.addSeries(seriesFat);

   i = 1.0f;
    c.moveToFirst();
    XYSeries seriesProtein = new XYSeries("Protein");
    while(!c.isAfterLast()) {

        seriesProtein.add(i++, c.getDouble(3));

        c.moveToNext();
    }
    dataset.addSeries(seriesProtein);

    c.moveToFirst();
    i = 1.0f;
    XYSeries seriesCarbs = new XYSeries("Carbs");
    while(!c.isAfterLast()) {

        seriesCarbs.add(i++, c.getDouble(4));
        c.moveToNext();
    }
    dataset.addSeries(seriesCarbs);

    return dataset;
}

以下是生成图表的代码：

public class ChartActivity {

public Intent getIntent(Context context)

{

XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();


XYMultipleSeriesRenderer mrenderer = new XYMultipleSeriesRenderer();
XYSeriesRenderer renderer = new XYSeriesRenderer();
mrenderer.addSeriesRenderer(renderer);

DatabaseAdapter dba = new DatabaseAdapter(context);
dba.open();


Intent intent = ChartFactory.getLineChartIntent(context, dba.getFatDataset(), mrenderer,"line graph");
dba.close();

return intent;

}

Answer 1

报告的错误非常明确：Dataset and renderer should not be null and should not have the same number of series表示您使用的是不同数量的系列和系列渲染器。事实上，您正在添加两个数据集：

//...
dataset.addSeries(seriesFat);
//....
dataset.addSeries(seriesCarbs);
//....

但您只有一个 XYSeriesRenderer()：

mrenderer.addSeriesRenderer(renderer);

在我看来，您的代码应该开始只是向XYMultipleSeriesRenderer()添加另一个渲染器，请尝试使用以下两行：

XYSeriesRenderer renderer2 = new XYSeriesRenderer();
mrenderer.addSeriesRenderer(renderer2);

AChartGraph有多条线

1 个答案: