JFreeChart - 将图表线的 SeriesStroke 从实线更改为虚线

Question

此处接受的答案 (JFreechart(Java) - How to draw lines that is partially dashed lines and partially solid lines?) 帮助我开始了更改图表上的系列笔划线的道路。在单步执行我的代码并观察更改后，我看到我的系列笔画实际上在它应该更改为“dashedStroke”时（在某个日期“dashedAfter”之后），但是当图表被渲染时，整个系列线是虚线.如何让系列线一开始是实线，在设定的日期之后是虚线？

/* 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

我认为你做对了，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 2 条线而不是 1 条线。你的第二条线将从你的第一条线结束的地方开始。如果您想大量更改笔画并且您想根据条件在循环的每次迭代中更改它，那可能会变得混乱，您的代码可能会变得更加复杂。或者只是为每个画一条新线。

Answer 2

您是否尝试过实现AbstractRenderer#getItemStroke？

在这个例子中，我对系列​​ 2 使用 x > 4 的虚线：

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);

虽然此示例使用和 XYSeries 而不是您应该能够根据需要修改它的日期。

这是完整的例子

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 3

我仍然遇到同样的问题，即线条没有从实线变为虚线，而是其中之一。

setDrawSeriesLineAsPath() 方法“控制是否将每个系列绘制为单个路径。”这排除了动态更改Stroke，因为getItemStroke() 在每个系列中只会被调用一次。

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