Java repaint()混淆

SwingUtilities.invokeLater(new Runnable() {
    public void run() {
        myComponent.repaint();
    }
});

myComponent.repaint(10, 10, 50, 50); // 重绘组件左上角 50x50 的区域

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class RepaintExample extends JFrame {
    private JLabel label;

    public RepaintExample() {
        setTitle("Repaint Example");
        setSize(300, 200);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        label = new JLabel("Hello, World!", SwingConstants.CENTER);
        add(label, BorderLayout.CENTER);

        JButton button = new JButton("Change Text");
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                label.setText("Text Changed!");
                label.repaint(); // 请求重绘标签
            }
        });
        add(button, BorderLayout.SOUTH);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new RepaintExample().setVisible(true);
            }
        });
    }
}