ball.java

动态显示皮球运动

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

public class Ball {
	public static void main(String args[]) {
		new frame();
	}
}

class frame extends JFrame implements ActionListener, ChangeListener {
	JPanel jp_HuaBan;
	JPanel jp_YuLan;
	JSlider js_red;
	JSlider js_green;
	JSlider js_blue;
	JSlider js_size;
	int x = 45, y = 45;
	int ball_size = 30;

	public frame() {
		super("ball");

		// 创建画板
		jp_HuaBan = new JPanel();
		jp_HuaBan.setBounds(20, 0, 450, 200);
		jp_HuaBan.setBackground(Color.white);

		// 创建球的予览框
		jp_YuLan = new JPanel();
		jp_YuLan.setBounds(350, 220, 120, 120);
		jp_YuLan.setBackground(Color.white);

		// 创建一个文本框作为状态栏
		JTextField jt_status = new JTextField("请选择球的颜色、大小然后点击按钮");
		jt_status.setBounds(1, 404, 492, 20);
		jt_status.setEditable(false);

		// 创建红、绿、蓝三个标签
		JLabel jl_red = new JLabel("红");
		jl_red.setBounds(20, 215, 30, 20);
		JLabel jl_green = new JLabel("绿");
		jl_green.setBounds(20, 260, 30, 20);
		JLabel jl_blue = new JLabel("蓝");
		jl_blue.setBounds(20, 305, 30, 20);
		JLabel jl_size = new JLabel("大小");
		jl_size.setBounds(20, 350, 30, 20);

		// 创建红、绿、蓝三个滑块
		js_red = new JSlider(SwingConstants.HORIZONTAL, 0, 255, 127);
		js_red.setBounds(50, 210, 250, 45);
		// 填充滑块
		js_red.putClientProperty("JSlider.isFilled", Boolean.TRUE);
		// 绘制勾号标记
		js_red.setPaintTicks(true);
		// 主要的勾号标记大小
		js_red.setMajorTickSpacing(50);
		// 次要的勾号标记大小
		js_red.setMinorTickSpacing(25);
		// 显示主要刻度的数字标记
		js_red.setPaintLabels(true);
		// 添加监听者
		js_red.addChangeListener(this);

		js_green = new JSlider(SwingConstants.HORIZONTAL, 0, 255, 127);
		js_green.setBounds(50, 255, 250, 45);
		js_green.putClientProperty("JSlider.isFilled", Boolean.TRUE);
		js_green.setPaintTicks(true);
		js_green.setMajorTickSpacing(50);
		js_green.setMinorTickSpacing(25);
		js_green.setPaintLabels(true);
		js_green.addChangeListener(this);
		js_blue = new JSlider(SwingConstants.HORIZONTAL, 0, 255, 127);
		js_blue.setBounds(50, 300, 250, 45);
		js_blue.putClientProperty("JSlider.isFilled", Boolean.TRUE);
		js_blue.setPaintTicks(true);
		js_blue.setMajorTickSpacing(50);
		js_blue.setMinorTickSpacing(25);
		js_blue.setPaintLabels(true);
		js_blue.addChangeListener(this);
		// 创建球的大小的滑块
		js_size = new JSlider(SwingConstants.HORIZONTAL, 10, 50, 30);
		js_size.setBounds(50, 345, 250, 45);
		js_size.putClientProperty("JSlider.isFilled", Boolean.TRUE);
		js_size.setPaintTicks(true);
		js_size.setMajorTickSpacing(10);
		js_size.setMinorTickSpacing(5);
		js_size.setPaintLabels(true);
		js_size.addChangeListener(this);

		// 创建按钮
		JButton jb = new JButton("ball");
		jb.setBounds(350, 360, 120, 30);
		jb.addActionListener(this);

		// 将所有对象添加到窗体
		Container c = this.getContentPane();
		c.setLayout(null);
		c.add(jp_HuaBan);
		c.add(jp_YuLan);
		c.add(jl_red);
		c.add(jl_green);
		c.add(jl_blue);
		c.add(jl_size);
		c.add(js_red);
		c.add(js_green);
		c.add(js_blue);
		c.add(js_size);
		c.add(jb);
		c.add(jt_status);
		// 设置窗体的位置和大小
		this.setBounds(100, 50, 500, 450);
		this.setResizable(false);
		this.setVisible(true);
		this.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				System.exit(0);
			}
		});
	}

	public void actionPerformed(ActionEvent e) {
		Color ball_color = new Color(js_red.getValue(), js_green.getValue(),
				js_blue.getValue());
		rball r = new rball(jp_HuaBan, js_size.getValue(), ball_color);
		r.start();
		lball l = new lball(jp_HuaBan, js_size.getValue(), ball_color);
		l.start();
	}

	public void stateChanged(ChangeEvent e) {
		// 获得jp_YuLan的画笔并在jp_YuLan的中心画个圆
		Graphics g = jp_YuLan.getGraphics();
		g.setColor(Color.white);
		g.fillOval(x, y, ball_size, ball_size);
		x = 60 - js_size.getValue() / 2;
		y = 60 - js_size.getValue() / 2;
		ball_size = js_size.getValue();
		g.setColor(new Color(js_red.getValue(), js_green.getValue(), js_blue
				.getValue()));
		g.fillOval(x, y, ball_size, ball_size);
		g.dispose();
	}
}

class lball extends Thread {
	// 从窗口左面出现的球
	JPanel jp_HuaBan;
	int ball_size;
	Color ball_color;

	public lball(JPanel j, int i, Color c) {
		// 获得画板的句柄
		jp_HuaBan = j;
		// 获得球的大小
		ball_size = i;
		// 获得球的颜色
		ball_color = c;
	}

	public void run() {
		Graphics g = jp_HuaBan.getGraphics();
		int x = 0, y = 0;
		// 计算画球时X轴,Y轴的最大坐标
		int HuaBan_x = 450 - ball_size;
		int HuaBan_y = 200 - ball_size;
		// 球移动的增量
		int x_increase = 5, y_increase = 5;
		while (true) {
			// 将上一次画的球擦掉
			g.setColor(Color.white);
			g.fillOval(x, y, ball_size, ball_size);
			// 画球
			g.setColor(ball_color);
			x = x + x_increase;
			y = y + y_increase;
			g.fillOval(x, y, ball_size, ball_size);
			// 判断球是否到达了边界,若到达了则转向
			if (x <= 0 || x >= HuaBan_x)
				x_increase = -x_increase;
			if (y <= 0 || y >= HuaBan_y)
				y_increase = -y_increase;
			try {
				// 休眠一段时间
				Thread.sleep(60);
			} catch (Exception e) {
			}
		}
	}
}

class rball extends Thread {
	// 从窗口左面出现的球
	JPanel jp_HuaBan;
	int ball_size;
	Color ball_color;

	public rball(JPanel j, int i, Color c) {
		jp_HuaBan = j;
		ball_size = i;
		ball_color = c;
	}

	public void run() {
		Graphics g = jp_HuaBan.getGraphics();
		int x = 450 - ball_size, y = 0;
		int HuaBan_x = x;
		int HuaBan_y = 200 - ball_size;
		int x_increase = -5, y_increase = 5;
		while (true) {

			g.setColor(Color.white);
			g.fillOval(x, y, ball_size, ball_size);
			g.setColor(ball_color);
			x = x + x_increase;
			y = y + y_increase;
			g.fillOval(x, y, ball_size, ball_size);
			if (x <= 0 || x >= HuaBan_x)
				x_increase = -x_increase;
			if (y <= 0 || y >= HuaBan_y)
				y_increase = -y_increase;
			try {
				Thread.sleep(30);
			} catch (Exception e) {
			}
		}
	}
}