小编Ran*_*eet的帖子

我正在尝试绘制图形，JButton单击时应显示图形。为了创建数据集，我正在获取一些值JTextField，然后创建一个图表并绘制它。我有两个问题：

1. 调整窗口大小后图表变得可见，并且
2. 当我更改文本字段值时，图表不会刷新。

这是我的程序：

public class Test extends JFrame {

private JPanel contentPane;
private JTextField textField;
private ChartPanel chartPanel;

public Test() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);

JPanel panel = new JPanel();
contentPane.add(panel, BorderLayout.WEST);
panel.setLayout(new MigLayout("", "[][grow]", "[][][][][]"));

JLabel lblA = new JLabel("a");
panel.add(lblA, "cell 0 2,alignx trailing");

textField = new JTextField();
panel.add(textField, "cell 1 2,growx");
textField.setColumns(10);

JButton btn = new JButton("Plot");
btn.addActionListener(new …

我只想在鼠标点击后绘制圆圈.由于paintComponent方法调用了自己,所以第一个圆绘制没有单击.

public class DrawPanel extends JPanel implements MouseListener {
private static final long serialVersionUID = 1L;
int x, y;

public DrawPanel() {
    setBackground(Color.WHITE);
    addMouseListener(this);
}

public void paintComponent(Graphics g) {
    Graphics2D g2 = (Graphics2D) g;
    g2.setColor(Color.red);
    g2.fillOval(x, y, 20, 20);
}

@Override
public void mouseClicked(MouseEvent e) {
    x = e.getX();
    y = e.getY();
    repaint();
}

}