我需要创建一个程序,在JFrame或JPanel上显示多个矩形。这是我到目前为止的代码:JPanel/JPanel上的随机矩形
import javax.swing.*;
import java.util.Random;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class RandomRectangles extends JFrame {
private static final int FRAME_HEIGHT = 300;
private static final int FRAME_WIDTH = 250;
private JButton fewer;
private JButton more;
private Random generator = new Random();
private int count;
private JPanel display;
private JPanel panel;
public RandomRectangles()
{
count = generator.nextInt(100);
setSize(FRAME_WIDTH, FRAME_HEIGHT);
this.setTitle("Random Rectangles");
display = new JPanel(new BorderLayout());
setLayout(new BorderLayout());
//display = new JPanel(new GridLayout(2,2));
JPanel buttons = new JPanel();
fewer = new JButton("Fewer");
more = new JButton("More");
buttons.add(fewer);
buttons.add(more);
class fewerNum implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
count = count/2;
}
}
ActionListener listener = new fewerNum();
fewer.addActionListener(listener);
class moreNum implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
count = count * 2;
}
}
ActionListener listener2 = new moreNum();
more.addActionListener(listener2);
for (int i = 0; i <= count; i++)
{
// display.add(new RectangleComponent());
add(new RectangleComponent());
}
//add(display, BorderLayout.CENTER);
add(buttons, BorderLayout.SOUTH);
}
}
上述代码编译但存在一些缺陷。单击按钮时不做任何事情,而不是向框架或面板添加RectangleComponent对象。 我还创建一个单独的RectangleComponent类来绘制一个矩形对象
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.util.Random;
import javax.swing.JComponent;
import javax.swing.JFrame;
public class RectangleComponent extends JComponent{
private Random generator = new Random();
private int xLeft;
private int yTop;
public RectangleComponent()
{
xLeft = generator.nextInt(100);
yTop = generator.nextInt(100);
}
public void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D) g;
Rectangle rec = new Rectangle(xLeft, yTop, 20, 40);
int amount = generator.nextInt(100);
g2.draw(rec);
}
}
什么,我要做的是:编写显示在随机位置的一些长方形的计划。供应按钮“更少”和“更多”可生成更少或更多的随机矩形。每次用户点击“较少”时,计数应该减半。每次用户点击“更多”时,计数应该加倍。
你的具体问题是什么? – jzd 2011-04-05 18:16:13
我需要知道如何显示多个矩形的框架或面板 – carlly 2011-04-05 18:18:24
小的一点,但这是一个需求的声明,而不是一个问题。问题以问号(?)结尾。 – 2011-04-05 18:28:30