Java 2D -文本垂直居中

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

public class VerticalCenteredText extends JPanel {
    private String text = "Hello, World!";

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;

        // 设置字体属性
        Font font = new Font("Arial", Font.PLAIN, 24);
        g2d.setFont(font);

        // 获取文本的尺寸
        FontMetrics fm = g2d.getFontMetrics();
        int textWidth = fm.stringWidth(text);
        int textHeight = fm.getHeight();

        // 计算文本的垂直居中位置
        int x = (getWidth() - textWidth) / 2;
        int y = (getHeight() - textHeight) / 2 + fm.getAscent();

        // 绘制文本
        g2d.drawString(text, x, y);
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("Vertical Centered Text");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 300);
        frame.setLocationRelativeTo(null);

        VerticalCenteredText panel = new VerticalCenteredText();
        frame.add(panel);

        frame.setVisible(true);
    }
}