由于可以使用 html 文本创建多行按钮，因此我尝试了 html 的 line-height 属性，使用小数、像素和百分比值来更改垂直行距。但徒劳无功。
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class LineSpacing extends JFrame {
public static final long serialVersionUID = 100L;
public LineSpacing() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(480, 240);
setLayout(new FlowLayout());
setLocationRelativeTo(null);
add(createBox("Decimal", new String[]{"0.8", "0.9", "1.1"}));
add(createBox("px", new String[]{"10px", "12px", "15px"}));
add(createBox("%", new String[]{"85%", "95%", "110%"}));
setVisible(true);
}
static public void main(String args[]) {
EventQueue.invokeLater(LineSpacing::new);
}
private Box createBox(String header, String[] values) {
Box box= Box.createVerticalBox();
JPanel p= new JPanel();
p.add(new JLabel(header, SwingConstants.CENTER));
box.add(p);
for (int i=0; i<3; i++) {
JButton b= new JButton("<html><center><span style='line-height:"+
values[i]+"'>First line<br>and the second</span></html>");
b.setPreferredSize(new Dimension(130, 40));
b.setMargin(new Insets(0,0,0,0));
box.add(b);
}
return box;
}
}
Swing 的 HTML 支持基于 HTML 3.2 的子集，并且不完全支持 CSS 样式，其中包括所有形式的 line-height 属性。
如果 Swing 中的 HTML 渲染引擎能够识别，则
line-height将
<span><div>line-heightdivline-height
JButton b = new JButton("<html><center><div style='line-height:" +
values[i] + "'>First line<br>and the second</div></html>");
如果 line-height 属性仍然不起作用，请使用显式间距方法，例如填充或添加带有内联字体大小的
<br>不要依赖 HTML 样式，而是使用自定义
JButtonJLabel示例：
import java.awt.*;
import javax.swing.*;
public class LineSpacingCustom extends JFrame {
public static final long serialVersionUID = 100L;
public LineSpacingCustom() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(480, 240);
setLayout(new FlowLayout());
setLocationRelativeTo(null);
add(createBox("Decimal", new float[]{0.8f, 0.9f, 1.1f}));
setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(LineSpacingCustom::new);
}
private Box createBox(String header, float[] spacings) {
Box box = Box.createVerticalBox();
JPanel p = new JPanel();
p.add(new JLabel(header, SwingConstants.CENTER));
box.add(p);
for (float spacing : spacings) {
JButton b = new LineHeightButton("First line\nand the second", spacing);
b.setPreferredSize(new Dimension(130, 60));
box.add(b);
}
return box;
}
}
class LineHeightButton extends JButton {
private final float lineSpacing;
public LineHeightButton(String text, float lineSpacing) {
super();
this.lineSpacing = lineSpacing;
setText(text);
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setFont(getFont());
String[] lines = getText().split("\n");
int y = getInsets().top;
for (String line : lines) {
g2.drawString(line, getInsets().left, y += g2.getFontMetrics().getHeight() * lineSpacing);
}
}
}