将JFreeChart添加到JPanel

Question

我正在创建一个swing应用程序，并希望将JfreeChart添加到JPanel中。我创建了一个方法，在该方法中我创建了如下所示的图表：

创建了一个全局变量：

JFreeChart chart;

public void createChart(){
        XYSeries series = new XYSeries("XYGraph");
           series.add(1, 1);
           series.add(1, 2);
           series.add(2, 1);
           series.add(3, 9);
           series.add(4, 10);

        // Add the series to your data set
           XYSeriesCollection dataset = new XYSeriesCollection();
           dataset.addSeries(series);

        // Generate the graph
           chart = ChartFactory.createXYLineChart(
           "XY Chart", // Title
           "x-axis", // x-axis Label
           "y-axis", // y-axis Label
           dataset, // Dataset
           PlotOrientation.VERTICAL, // Plot Orientation
           true, // Show Legend
           true, // Use tooltips
           false // Configure chart to generate URLs?
        );

    }

JPanel reporting = new JPanel();
ChartPanel CP = new ChartPanel(chart);
reporting.add(CP,BorderLayout.CENTER);
reporting.validate();
reporting.setBounds(47, 59, 921, 439);
frame.getContentPane().add(reporting);
reporting.setLayout(new BorderLayout(0, 0));

JButton btnReporting = new JButton("Reporting");
        btnReporting.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                createChart();
            }
        });

由于某种原因，当我点击按钮时，图表没有显示出来。

Answer 1

一堆断章取义的代码并不能让你很容易地理解你在做什么，但类似于...

首先，您需要删除之前从UI中显示的任何内容，否则您将在屏幕上显示多个图表，这可能会导致其他问题。

接下来，当您创建图表时，您需要实际添加到屏幕中。它不会仅仅因为你创建了一个新的图表就“神奇地”更新

// import free chart classes
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private JPanel reportingPane;

        public TestPane() {
            setLayout(new BorderLayout());
            reportingPane = new JPanel(new BorderLayout());
            JButton btnReporting = new JButton("Reporting");
            btnReporting.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent arg0) {
                    JFreeChart chart = createChart();
                    reportingPane.removeAll();
                    reportingPane.add(new ChartPanel(chart));
                    revalidate();
                    repaint();
                }
            });
            add(reportingPane);
            add(btnReporting, BorderLayout.SOUTH);
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }

        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            g2d.dispose();
        }

    }

    public JFreeChart createChart() {
        XYSeries series = new XYSeries("XYGraph");
        series.add(1, 1);
        series.add(1, 2);
        series.add(2, 1);
        series.add(3, 9);
        series.add(4, 10);

        // Add the series to your data set
        XYSeriesCollection dataset = new XYSeriesCollection();
        dataset.addSeries(series);

        // Generate the graph
        JFreeChart chart = ChartFactory.createXYLineChart(
                        "XY Chart", // Title
                        "x-axis", // x-axis Label
                        "y-axis", // y-axis Label
                        dataset, // Dataset
                        PlotOrientation.VERTICAL, // Plot Orientation
                        true, // Show Legend
                        true, // Use tooltips
                        false // Configure chart to generate URLs?
        );

        return chart;

    }

}

至少应该证明基本的概念...