Java如何在矩形中显示字符串？

在Java的GUI编程中，如何在矩形中显示字符串？

以下示例演示如何使用drawRect()方法在每个字符周围绘制一个矩形来显示矩形中的每个字符。

package com.zaixian;

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

public class DisplayTextInRectangle extends JPanel {
    public void paint(Graphics g) {
        g.setFont(new Font("", 0, 50));
        FontMetrics fm = getFontMetrics(new Font("", 0, 50));
        String s = "Max vs. Min";
        int x = 5;
        int y = 5;

        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            int h = fm.getHeight();
            int w = fm.charWidth(c);

            g.drawRect(x, y, w, h);
            g.drawString(String.valueOf(c), x, y + h);
            x = x + w;
        }
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setContentPane(new DisplayTextInRectangle());
        frame.setSize(500, 700);
        frame.setVisible(true);
    }
}

上述代码示例将产生以下结果。

示例-2

以下是在矩形中显示字符串的另一个示例。

package com.zaixian;


import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JComponent;
import javax.swing.JFrame;

class MyCanvas extends JComponent {
   String s = "This is a message.";
   int x = 45;
   int y = 45;
   public void paint(Graphics g) {
      g.drawRect (10, 10, 200, 200);
      g.setColor(Color.blue);
      g.drawString(s, x, y);
   }
}
public class DisplayTextInRectangle2 {
   public static void main(String[] a) {
      JFrame window = new JFrame();
      window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      window.setBounds(30, 30, 300, 300);
      window.getContentPane().add(new MyCanvas());
      window.setVisible(true);
   }
}

上述代码示例将产生以下结果。