Question

用java画板drawString的字，可以改变大小吗

Answer 1

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Painter extends JFrame{

/**
*
*/
private static final long serialVersionUID = 8160427604782702376L;
CanvasPanel canvas = new CanvasPanel();;

public Painter() {
super("Star");
this.add(canvas);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.pack();
this.setResizable(false);
this.setLocationRelativeTo(null);
this.setVisible(true);
}

public static void main(String[] args) {
new Painter();
}
}

class CanvasPanel extends JPanel implements ActionListener{

/**
*
*/
private static final long serialVersionUID = -4642528854538741028L;
private JButton[] btn = new JButton[4];
private String[] btn_name = {"+", "-", "R", "L"};
private int center_x = 200, center_y = 200, radius = 100, degree = 0;

public CanvasPanel() {
this.setPreferredSize(new Dimension(400, 500));
this.setLayout(null);
for(int i = 0; i < 4; i++) {
btn[i] = new JButton(btn_name[i]);
btn[i].setBounds(160 + i * 60, 425, 50, 50);
btn[i].addActionListener(this);
this.add(btn[i]);
}
}

@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
for(int i = 0; i < 5; i++) {
g.drawLine( (int) (center_x + radius * Math.sin(Math.toRadians(degree + 72 * i))),
(int) (center_y - radius * Math.cos(Math.toRadians(degree + 72 * i))),
(int) (center_x + radius * Math.sin(Math.toRadians(degree + 72 * i + 144))),
(int) (center_y - radius * Math.cos(Math.toRadians(degree + 72 * i + 144))));
}
}

public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
if(e.getActionCommand() == "+") {
if(radius < 200)
radius += 2;
repaint();
} else if(e.getActionCommand() == "-") {
if(radius > 0)
radius -= 2;
repaint();
} else if(e.getActionCommand() == "R") {
degree = (degree + 2) % 360;
repaint();
} else if(e.getActionCommand() == "L") {
degree = (degree - 2) % 360;
repaint();
}
}
}