描画する円の数を取り、ランダムな場所/サイズで drawPanel に描画する GUI を作成しようとしています。actionListener で円を描こうとすると、drawOval に赤い線が表示されます
ファーストクラス:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.JTextArea;
/**
*
* @author Chris
*
*/
public class CirclesPanel extends JPanel{
private JButton draw, clear;
private JTextArea textArea;
private JPanel panel, drawPanel, buttonPanel;
private int count;
/**constructor
* builds the frame
*/
public CirclesPanel(){
//creates buttons and textArea
draw = new JButton("Draw");
clear = new JButton("Clear");
textArea = new JTextArea(1,10);
textArea.setBorder(BorderFactory.createTitledBorder("Circles"));
//creats panel
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
setPreferredSize(new Dimension(620, 425));
//creates subpanel drawPanel
JPanel drawPanel = new JPanel();
drawPanel.setPreferredSize(new Dimension(450,400));
drawPanel.setBackground(Color.BLACK);
//creates subpanel buttonPanel
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout(new GridLayout(3,1));
//adds all the content to the frame
add(panel);
add(buttonPanel, BorderLayout.WEST);
add(drawPanel, BorderLayout.EAST);
buttonPanel.add(textArea);
buttonPanel.add(draw);
buttonPanel.add(clear);
//reads if the draw button is clicked
draw.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
count =Integer.parseInt(textArea.getText());//takes the count in
repaint();//repaints the picture to add the circles
}
});
//reads if the clear button is clicked
clear.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
count=0;//sets the count to 0 so nothing is painted
repaint();//repaints the window
}
});
}
/**Paint component
* draws the random circles
*/
public void paintComponent(Graphics g) {
Random generator = new Random();
int x, y, diameter;
for(int i = 0; i < count; i++){ //loop that takes the count and does this "x" times
g.setColor(Color.BLUE);//sets color to blue
x = generator.nextInt(90);//random location for x
y = generator.nextInt(90);//random location for y
diameter = generator.nextInt(30);//random size
g.fillOval(x, y, diameter, diameter);//draws the circle
}
}
}
2級
import javax.swing.JFrame;
public class Circles {
public static void main(String[]args){
JFrame frame = new JFrame("Cicles HW9");
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new CirclesPanel());
frame.pack();
frame.setVisible(true);
}
}