如何在Java中获得真正的字符串高度？

在Java中获得真正的字符串高度，可以使用以下方法：

使用FontMetrics类：

import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class StringHeight extends JPanel {
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;
        FontMetrics fm = g2d.getFontMetrics();
        String text = "Hello, World!";
        int stringHeight = fm.getHeight();
        System.out.println("String height: " + stringHeight);
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("String Height");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(new StringHeight());
        frame.setSize(300, 200);
        frame.setVisible(true);
    }
}

使用TextLayout类：

import java.awt.Font;
import java.awt.font.TextLayout;
import java.text.AttributedCharacterIterator;
import java.text.AttributedString;

public class StringHeight {
    public static void main(String[] args) {
        String text = "Hello, World!";
        Font font = new Font("Arial", Font.PLAIN, 12);
        AttributedString attributedString = new AttributedString(text);
        attributedString.addAttribute(TextAttribute.FONT, font);
        AttributedCharacterIterator iterator = attributedString.getIterator();
        TextLayout layout = new TextLayout(iterator);
        float stringHeight = layout.getAscent() + layout.getDescent() + layout.getLeading();
        System.out.println("String height: " + stringHeight);
    }
}

这两种方法都可以获得字符串的真实高度，可以根据实际需求选择使用。