我知道这个问题早先被问过（here，here和here），但提供的解决方案不起作用。因此，请不要将其标记为重复。我正在使用JFreeChart绘制折线图。然后我将这个图表放在一个JPanel中，然后放入tabbedPane。我知道将JPanel直接放在JFrame中可以调整大小，但我怎么能这样做呢？
public class DynamicLineAndTimeSeriesChart extends JPanel implements ActionListener {
private ArrayList<TimeSeries> Series = new ArrayList<TimeSeries>();
private ArrayList<Double> Last = new ArrayList<Double>();
private String Id1;
private Timer timer = new Timer(250, this);
public DynamicLineAndTimeSeriesChart(String id) {
Runtime runtime = Runtime.getRuntime();
int NoOfProc = runtime.availableProcessors();
for (int i = 0; i < NoOfProc; i++) {
Last.add(new Double(100.0));
Series.add(new TimeSeries("Core" + i, Millisecond.class));
}
Id1 = id;
final TimeSeriesCollection dataset = new TimeSeriesCollection();
for (int i = 0; i < NoOfProc; i++) {
dataset.addSeries(this.Series.get(i));
}
final JFreeChart chart = createChart(dataset);
timer.setInitialDelay(1000);
chart.setBackgroundPaint(Color.LIGHT_GRAY);
//Created JPanel to show graph on screen
final JPanel content = new JPanel(new GridLayout());
final ChartPanel chartPanel = new ChartPanel(chart);
content.add(chartPanel, BorderLayout.CENTER);
content.revalidate();
this.add(content);
timer.start();
}
createChart是JFreeChart类型的方法。这个类在另一个类中调用
JPanel main = new JPanel(new BorderLayout());
main.add(demo);
jTabbedPane1.add("Core", main);
demo.setVisible(true);
框架设计是使用NetBeans完成的。我已经尝试了所有解决方案，例如将布局从BorderLayout更改为GridBagLayout，甚至是提到的here。
当框架调整大小时，BorderLayout.CENTER应该让ChartPanel成长。我猜你有一个带有JPanel的FlowLayout，它继续使用图表面板的首选大小。由于FlowLayout是默认值，您可能需要查找它。
编辑：有一个完整的示例here，它将一个折线图添加到选项卡式窗格。
编辑：你的DynamicLineAndTimeSeriesChart有默认的FlowLayout;我想你想要一个GridLayout。
public DynamicLineAndTimeSeriesChart(String id) {
this.setLayout(new GridLayout());
…
}
没有看到你的所有代码，它只能是猜测。但是，作为一种解决方法，您可以让您的JPanel使用ComponentListener监听resize事件，如下所示：
content.addComponentListener(new ComponentAdapter(){
public void componentResized(ActionEvent e){
chartPanel.setSize(content.getSize());
}
});
我有同样的问题，我设法解决这个问题：（1）创建一个自定义类，扩展JPanel（2）以某种方式得到大小，你想传递给你的图表（3）创建一个返回一个方法“ChartPanel”对象是这样的：
ChartPanel chart() {
//... custom code here
JFreeChart chart = ChartFactory.createPieChart(title, pieDataset, false, false, false );`enter code here`
// Now: this is the trick to manage setting the size of a chart into a panel!:
return new ChartPanel(chart) {
public Dimension getPreferredSize() {
return new Dimension(width, height);
}
};
}
我准备了一个SSCCE让你知道它是如何工作的：
import java.awt.Dimension;
import java.util.ArrayList;
import javax.swing.JFrame;
import javax.swing.JPanel;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.data.general.DefaultPieDataset;
public class MyPieChart extends JPanel {
public static void main(String[] args) {
example1();
example2();
example3();
}
public static void example1() {
JPanel panel = new JPanel();
panel.setBounds(50, 80, 100, 100);
MyPieChart piePanel = new MyPieChart("Example 1", dataset(), panel);
panel.add(piePanel);
JFrame frame = new JFrame();
frame.setLayout(null);
frame.setBounds(10, 10, 200, 300);
frame.add(panel);
frame.setVisible(true);
}
public static void example2() {
MyPieChart piePanel = new MyPieChart("Example 2", dataset(), 30, 50, 100, 100);
JFrame frame = new JFrame();
frame.setLayout(null);
frame.setBounds(210, 10, 200, 300);
frame.add(piePanel);
frame.setVisible(true);
}
public static void example3() {
MyPieChart piePanel = new MyPieChart("Example 3", dataset(), 100, 100);
piePanel.setLocation(0,0);
JFrame frame = new JFrame();
frame.setLayout(null);
frame.setBounds(410, 10, 200, 300);
frame.add(piePanel);
frame.setVisible(true);
}
static ArrayList<ArrayList<String>> dataset() {
ArrayList<ArrayList<String>> dataset = new ArrayList<ArrayList<String>>();
dataset.add(row( "Tom", "LoggedIn", "Spain" ));
dataset.add(row( "Jerry", "LoggedOut", "England" ));
dataset.add(row( "Gooffy", "LoggedOut", "France" ));
return dataset;
}
static ArrayList<String> row(String name, String actualState, String country) {
ArrayList<String> row = new ArrayList<String>();
row.add(name); row.add(actualState); row.add(country);
return row;
}
ArrayList<ArrayList<String>> dataset;
DefaultPieDataset pieDataset = new DefaultPieDataset();
int width, height, posX, posY;
int colState = 1;
String title;
String LoggedIn = "LoggedIn";
String LoggedOut = "LoggedOut";
public MyPieChart(String title, ArrayList<ArrayList<String>> dataset, int...args) {
if(args.length==2) {
this.width = args[0];
this.height = args[1];
this.setSize(width, height);
}
else if(args.length==4) {
this.posX = args[0];
this.posY = args[1];
this.width = args[2];
this.height = args[3];
this.setBounds(posX, posY, width, height);
}
else {
System.err.println("Error: wrong number of size/position arguments");
return;
}
this.title = title;
this.dataset = dataset;
this.add(chart());
}
public MyPieChart(String title, ArrayList<ArrayList<String>> dataset, JPanel panel) {
this.title = title;
this.dataset = dataset;
this.width = panel.getWidth();
this.height = panel.getHeight();
this.setBounds(panel.getBounds());
this.add(chart());
}
ChartPanel chart() {
int totalLoggedIn = 0;
int totalLoggedOut = 0;
for(ArrayList<String> user : dataset) {
if(user.get(colState).equals(LoggedIn)) totalLoggedIn++;
else totalLoggedOut++;
}
pieDataset.clear();
pieDataset.setValue(LoggedIn +": "+ totalLoggedIn, totalLoggedIn);
pieDataset.setValue(LoggedOut +": "+ totalLoggedOut, totalLoggedOut);
JFreeChart chart = ChartFactory.createPieChart(title, pieDataset, false, false, false );
return new ChartPanel(chart) { // this is the trick to manage setting the size of a chart into a panel!
public Dimension getPreferredSize() {
return new Dimension(width, height);
}
};
}
}
我真的希望它有所帮助！