Question

这里接受的答案（JFreechart(Java) - How to draw lines that is partially dashed lines and partially solid lines?）帮助我开始改变我的图表上的系列线条。单步执行我的代码并观察更改后，我发现我的seriesstroke实际上确实改为“dashedStroke”（当某个日期之后为“dashedAfter”），但是当渲染图表时整个系列行都是虚线。如何让系列线首先绘制为实线并在设定的日期之后变为虚线？

/* series line modifications */
final Number dashedAfter = timeNowDate.getTime();

XYLineAndShapeRenderer render = new XYLineAndShapeRenderer() {
  Stroke regularStroke = new BasicStroke();
  Stroke dashedStroke = new BasicStroke(
                            1.0f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND,
                            1.0f, new float[] {10.0f, 6.0f}, 0.0f );
  @Override
  public Stroke getItemStroke(int row, int column) {
    Number xVal = cd.getXValue(row, column);
    if (xVal.doubleValue() > dashedAfter.doubleValue()) { 
      return dashedStroke; 
    } else { 
      return regularStroke; 
    }
  }
};
render.setBaseShapesVisible(false);
render.setBaseShapesFilled(true);
render.setDrawSeriesLineAsPath(true);
plot.setRenderer(render);

Answer 1

您是否尝试过实施AbstractRenderer#getItemStroke？

enter image description here

在这个例子中，我使用虚线表示x> 4系列2：

XYLineAndShapeRenderer renderer = new XYLineAndShapeRenderer(){
    Stroke soild = new BasicStroke(2.0f);
    Stroke dashed =  new BasicStroke(1.0f,BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER, 10.0f, new float[] {10.0f}, 0.0f);
    @Override
    public Stroke getItemStroke(int row, int column) {
if (row == 2){
  double x = dataset.getXValue(row, column);
  if ( x > 4){
    return dashed;
  } else {
    return soild;
  } 
} else
  return super.getItemStroke(row, column);
    }
  };
  renderer.setBaseShapesVisible(true);
  renderer.setBaseShapesFilled(true);
  renderer.setBaseStroke(new BasicStroke(3));
  plot.setRenderer(renderer);

虽然这个示例正在使用和XYSeries而不是日期，但您可以根据需要修改它。

以下是完整示例

import java.awt.BasicStroke;
import java.awt.Stroke;

import javax.swing.JPanel;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.data.xy.XYDataset;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RefineryUtilities;

public class LineChartDemo2 extends ApplicationFrame {

    public LineChartDemo2(String title) {
        super(title);
        JPanel chartPanel = createDemoPanel();
        chartPanel.setPreferredSize(new java.awt.Dimension(500, 270));
        setContentPane(chartPanel);
    }

    private static JFreeChart createChart(final XYDataset dataset) {

        JFreeChart chart = ChartFactory.createXYLineChart(
            "Line Chart Demo: XYLineAndShapeRenderer",     
            "X",                     
            "Y",                     
            dataset,              
            PlotOrientation.VERTICAL,
            false,                     
            false,                 
            false             
        );

        XYPlot plot = (XYPlot) chart.getPlot();
        plot.setDomainPannable(true);
        plot.setRangePannable(true);

        XYLineAndShapeRenderer renderer = new XYLineAndShapeRenderer(){
            Stroke soild = new BasicStroke(2.0f);
            Stroke dashed =  new BasicStroke(1.0f,BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER, 10.0f, new float[] {10.0f}, 0.0f);
            @Override
            public Stroke getItemStroke(int row, int column) {
                if (row == 2){
                    double x = dataset.getXValue(row, column);
                    if ( x > 4){
                        return dashed;
                    } else {
                        return soild;
                    } 
                } else
                    return super.getItemStroke(row, column);
            }
        };

        renderer.setBaseShapesVisible(true);
        renderer.setBaseShapesFilled(true);
        renderer.setBaseStroke(new BasicStroke(3));
        plot.setRenderer(renderer);
        return chart;
    }

    public static JPanel createDemoPanel() {
        JFreeChart chart = createChart(createDataset());
        ChartPanel panel = new ChartPanel(chart);
        panel.setMouseWheelEnabled(true);
        return panel;
    }

    public static void main(String[] args) {
        LineChartDemo2 demo = new LineChartDemo2(
                "JFreeChart");
        demo.pack();
        RefineryUtilities.centerFrameOnScreen(demo);
        demo.setVisible(true);
    }

    private static XYDataset createDataset() {

        XYSeries series1 = new XYSeries("First");
        series1.add(1.0, 1.0);
        series1.add(2.0, 4.0);
        series1.add(3.0, 3.0);
        series1.add(4.0, 5.0);
        series1.add(5.0, 5.0);
        series1.add(6.0, 7.0);
        series1.add(7.0, 7.0);
        series1.add(8.0, 8.0);

        XYSeries series2 = new XYSeries("Second");
        series2.add(1.0, 5.0);
        series2.add(2.0, 7.0);
        series2.add(3.0, 6.0);
        series2.add(4.0, 8.0);
        series2.add(5.0, 4.0);
        series2.add(6.0, 4.0);
        series2.add(7.0, 2.0);
        series2.add(8.0, 1.0);

        XYSeries series3 = new XYSeries("Third");
        series3.add(3.0, 4.0);
        series3.add(4.0, 3.0);
        series3.add(5.0, 2.0);
        series3.add(6.0, 3.0);
        series3.add(7.0, 6.0);
        series3.add(8.0, 3.0);
        series3.add(9.0, 4.0);
        series3.add(10.0, 3.0);

        XYSeriesCollection dataset = new XYSeriesCollection();
        dataset.addSeries(series1);
        dataset.addSeries(series2);
        dataset.addSeries(series3);

        return dataset;

    }


}

Answer 2

我仍然有同样的问题，这条线不是从固体变为虚线，而是一个或另一个。

setDrawSeriesLineAsPath()方法“控制是否将每个系列绘制为单个路径。”这样就无法动态更改Stroke，因为getItemStroke()每个系列只会调用一次。

附录：验证这一点的简单方法是在@ GrahamA的示例中调用setDrawSeriesLineAsPath()并在调试器中查看drawFirstPassShape()。

Answer 3

我认为你做得对，如果它不起作用，也许它不可能？我只是在这里猜测，但你可以画出2行代替1.你的第二行将从你的第一行结束开始。如果你想改变笔划很多，那么你可能会变得很乱，因为你想根据条件在每次迭代循环中改变它，你的代码可能会变得更复杂。或者只为每个画一条新线。

JFreeChart - 将图表行的SeriesStroke从实线更改为虚线

3 个答案: