jfreechar.getParent()没有这个方法

非常抱歉，我犯了一个错误。JFreeChart没有getParent()方法。如果你想获取ChartPanel对象，你可以在创建ChartPanel时将JFreeChart对象作为参数传递进去，例如：

ChartPanel chartPanel = new ChartPanel(chart);

这样，你就可以通过chartPanel对象访问JFreeChart对象的各种属性，例如获取宽度和高度：

int width = chartPanel.getWidth();
int height = chartPanel.getHeight();

请注意，这里的chart是你的JFreeChart对象。如果你已经创建了JFreeChart对象，你可以将它替换为你的对象。

相关问题

生成一个曲线图JFreechar对象

好的，以下是在Java中创建曲线图JFreeChart对象的示例代码：

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.category.DefaultCategoryDataset;

import javax.swing.*;
import java.awt.*;

public class LineChart extends JFrame {

    public LineChart(String title) {
        super(title);
        JFreeChart chart = createChart();
        ChartPanel chartPanel = new ChartPanel(chart);
        chartPanel.setPreferredSize(new Dimension(500, 270));
        setContentPane(chartPanel);
    }

    private JFreeChart createChart() {
        DefaultCategoryDataset dataset = new DefaultCategoryDataset();
        dataset.addValue(1.0, "Series 1", "Category 1");
        dataset.addValue(4.0, "Series 1", "Category 2");
        dataset.addValue(3.0, "Series 1", "Category 3");
        dataset.addValue(5.0, "Series 1", "Category 4");
        dataset.addValue(5.0, "Series 1", "Category 5");
        dataset.addValue(7.0, "Series 1", "Category 6");
        dataset.addValue(7.0, "Series 1", "Category 7");
        dataset.addValue(8.0, "Series 1", "Category 8");

        JFreeChart chart = ChartFactory.createLineChart(
                "Line Chart",
                "Category",
                "Value",
                dataset,
                PlotOrientation.VERTICAL,
                true,
                true,
                false
        );

        return chart;
    }

    public static void main(String[] args) {
        LineChart chart = new LineChart("Line Chart");
        chart.pack();
        RefineryUtilities.centerFrameOnScreen(chart);
        chart.setVisible(true);
    }
}

这个示例代码创建了一个简单的曲线图，并在窗口中显示出来。你可以根据你的需要对代码进行修改和扩展。

创建一个动态曲线图JFreechar对象

好的，以下是在Java中创建动态曲线图JFreeChart对象的示例代码：

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.XYPlot;
import org.jfree.data.time.Second;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;
import org.jfree.data.xy.XYDataset;

import javax.swing.*;
import java.awt.*;

public class DynamicLineChart extends JFrame {

    private TimeSeries series;

    public DynamicLineChart(String title) {
        super(title);
        series = new TimeSeries("Random Data");
        TimeSeriesCollection dataset = new TimeSeriesCollection(series);
        JFreeChart chart = createChart(dataset);
        ChartPanel chartPanel = new ChartPanel(chart);
        chartPanel.setPreferredSize(new Dimension(500, 270));
        setContentPane(chartPanel);
    }

    private JFreeChart createChart(XYDataset dataset) {
        JFreeChart chart = ChartFactory.createTimeSeriesChart(
                "Dynamic Line Chart",
                "Time",
                "Value",
                dataset,
                true,
                true,
                false
        );

        XYPlot plot = chart.getXYPlot();
        plot.setBackgroundPaint(Color.lightGray);
        plot.setDomainGridlinePaint(Color.white);
        plot.setRangeGridlinePaint(Color.white);

        return chart;
    }

    public void addData(double data) {
        series.add(new Second(), data);
    }

    public static void main(String[] args) {
        DynamicLineChart chart = new DynamicLineChart("Dynamic Line Chart");
        chart.pack();
        RefineryUtilities.centerFrameOnScreen(chart);
        chart.setVisible(true);

        while (true) {
            double data = Math.random() * 100;
            chart.addData(data);
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

这个示例代码创建了一个动态曲线图，并在窗口中显示出来。通过addData方法可以向图表中添加数据，示例代码中每隔一秒钟随机生成一个数据点并添加到图表中。你可以根据你的需要对代码进行修改和扩展。