java - JFreeChart:使用 ChartMouseEvent 在散点图上显示数据

Question

我的目标是使用 JFreeChart XY 散点图显示一些数据，以便在按下 jButton 时显示该图，并且还应该可以单击该图上的数据点并查看有关它们的一些附加信息。按下 jButton 后，将从外部数据文件导入数据点并创建散点图。绘图按预期工作，但绘图不会对鼠标单击使用react。

我尝试将 ChartMouseListener 添加到包含散点图的图表面板，但似乎它没有记录鼠标单击或对单击没有反应。

这是代码的一部分:

    ChartPanel chapa = new ChartPanel(scatterchart);

    chapa.addChartMouseListener(new ChartMouseListener(){

          @Override
          public void chartMouseClicked(ChartMouseEvent event){

                ChartEntity entity = event.getEntity();

                if (entity != null && entity instanceof XYItemEntity) {
                        XYItemEntity ent = (XYItemEntity) entity;

                        int serindex = ent.getSeriesIndex();
                        int itemindex = ent.getItem();

                        JOptionPane.showMessageDialog(null, serindex);
                        System.out.println(serindex);
                }
         }
         @Override
         public void chartMouseMoved(ChartMouseEvent cme) {}
    });

    jPanel2.setLayout(new java.awt.BorderLayout());
    jPanel2.add(chapa, BorderLayout.CENTER);
    jPanel2.validate();

在该部分之上创建了散点图。所有这些代码都位于 jButtonActionPerformed 方法内，并由 try 和 catch block 包围(用于捕获处理图表数据所需的 BiffException、IOException 和 SQLException)。

当点击散点图上的数据点时，应该出现一个消息窗口，其中包含包含该数据点的 XY 系列索引，并且该索引也应该由 System.out.println 传递，但实际上当单击数据点。代码中有什么问题？感谢您的帮助。

Answer 1

我设法找到了解决方案。代码没问题，有一个更简单的错误 - 程序包含许多生成散点图的 jButton，但并非每个 jButton 都使用 ChartMouseListener 创建图表。运行程序时，按下了一个这样的 jButton，而不是右侧的 jButton，因此散点图不会对点击使用react，因为它没有 ChartMouseListener...

在寻找解决方案并尝试不同的选项时，我写了一个更简单的代码(只有一个 jButton 和一个 jPanel)，具有相同的想法。它创建一个简单的散点图并打印出单击的数据点的 x 坐标。我将其发布在这里，也许它可以作为某人的示例(复制并将其另存为“graphclick”):

import java.awt.BorderLayout;
import javax.swing.JOptionPane;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartMouseEvent;
import org.jfree.chart.ChartMouseListener;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.ChartEntity;
import org.jfree.chart.entity.XYItemEntity;
import org.jfree.chart.plot.XYPlot;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;

public class graphclick extends javax.swing.JFrame {

    public graphclick() {
        initComponents();
    }

    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        jButton1 = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 0, Short.MAX_VALUE)
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 421, Short.MAX_VALUE)
        );

        jButton1.setText("jButton1");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addContainerGap())
            .addGroup(layout.createSequentialGroup()
                .addGap(365, 365, 365)
                .addComponent(jButton1)
                .addContainerGap(383, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(18, 18, 18)
                .addComponent(jButton1)
                .addContainerGap(59, Short.MAX_VALUE))
        );

        pack();
    }

    // HERE IS THE MAIN ACTION TAKING PLACE
    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         

        XYSeriesCollection impser = new XYSeriesCollection();
        try {
        XYSeries series1 = new XYSeries("Series1");
        series1.add(1.0, 2.0);
        series1.add(2.0, 2.5);
        series1.add(3.0, 2.0);

        impser.addSeries(series1);
        JFreeChart scatterchart = ChartFactory.createScatterPlot("", "X", "Y", impser);

        XYPlot xyplot = scatterchart.getXYPlot();
        ValueAxis domainAxis = xyplot.getDomainAxis(); // x-axis
        ValueAxis rangeAxis = xyplot.getRangeAxis();

        domainAxis.setRange(0.0, impser.getDomainUpperBound(false) + 1.0);
        rangeAxis.setRange(0.0, impser.getRangeUpperBound(true) + 1.0);

        jPanel1.removeAll();
        ChartPanel chapa = new ChartPanel(scatterchart);

        chapa.addChartMouseListener(new ChartMouseListener(){
            @Override
            public void chartMouseClicked(ChartMouseEvent event){

                ChartEntity entity = event.getEntity();

                if (entity != null && entity instanceof XYItemEntity) {
                    XYItemEntity ent = (XYItemEntity) entity;

                    int sindex = ent.getSeriesIndex();
                    int iindex = ent.getItem();

                    XYSeries ser = impser.getSeries(sindex);

                    System.out.println(impser.getX(sindex, iindex));

                }
            }
            @Override
            public void chartMouseMoved(ChartMouseEvent cme) {}
        });

        jPanel1.setLayout(new java.awt.BorderLayout());
        jPanel1.add(chapa, BorderLayout.CENTER);
        jPanel1.validate();

        } catch (Exception e) {
            JOptionPane.showMessageDialog(null, "Error: " + e.getMessage());
        }
    }                                        

    public static void main(String args[]) {

        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(graphclick.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(graphclick.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(graphclick.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(graphclick.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new graphclick().setVisible(true);
            }
        });
    }

    private javax.swing.JButton jButton1;
    private javax.swing.JPanel jPanel1;               

}