java答案第九章.docx

1、java答案第九章/NetWork类import java.awt.Graphics;import javax.swing.JFrame;public classtest9_1 extends JFramepublic NetWork()/ 设置窗体大小this.setSize(130, 130);/设置窗体大小不可改变this.setResizable(false);/ 设置默认关闭方式，关闭窗体的同时结束程序this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);/ 将窗体显示出来this.setVisible(true);/横纵格之间都间隔

2、10像素，起点在（20,40）public void paint(Graphics g)/绘制横向线for(int i=0;i=5;i+)g.drawLine(20, 40+i*10, 110, 40+i*10);/绘制纵向线for(int i=0;i=9;i+)g.drawLine(20+i*10, 40, 20+i*10, 90);public static void main(String args)new test9_1();运行结果：2.编写一个程序，该程序以不同的颜色随机产生三角形，每个三角形用不同的颜色进行填充。/Triangle类import java.awt.Color;im

3、port java.awt.Graphics;import java.util.Random;import javax.swing.JFrame;public class Triangle extends JFrameRandom rnd = new Random();/这里定义4个三角形int x=new int43;int y=new int43;int color=new int43;public Triangle()for(int i=0;i4;i+)for(int j=0;j3;j+)colorij=rnd.nextInt(255);xij=rnd.nextInt(i*100+100

4、);yij=rnd.nextInt(i*100+100)+50;/加50像素是为了避免顶到窗体上沿/窗体标题this.setTitle(随机三角形);/窗体大小this.setSize(500,500);/窗体大小不可变this.setResizable(false);/关闭窗体的同时结束程序this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);/显示窗体this.setVisible(true);public void paint(Graphics g)for(int i=0;i4;i+)g.setColor(new Color(colori

5、0,colori1,colori2); g.fillPolygon(xi, yi, 3);public static void main(String args)new Triangle();运行结果：3.编写一个Applet，该程序请求用户输入圆的半径，然后显示该圆的直径、周长和面积。/test9_3import javax.swing.*;import java.awt.*;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;public class test9_3 extends JApplet /

6、声明5个标签private JLabel jLabel1;private JLabel jLabel2;private JLabel jLabel3;private JLabel jLabel4;private JLabel jLabel5;/1个单行文本private JTextField textOfRadius;/2个按钮private JButton jButton1;private JButton jButton2;/初始化public void init() try java.awt.EventQueue.invokeAndWait(new Runnable() public vo

7、id run() initComponents();); catch (Exception ex) ex.printStackTrace();private void initComponents() /声明8个组件jLabel1 = new JLabel(输入圆的半径：, SwingConstants.CENTER);jLabel2 = new JLabel(圆的周长：, SwingConstants.CENTER);jLabel3 = new JLabel(, SwingConstants.CENTER);jLabel4 = new JLabel(圆的面积：, SwingConstants

8、.CENTER);jLabel5 = new JLabel(, SwingConstants.CENTER);textOfRadius = new JTextField(半径);jButton1 = new JButton(计算);jButton2 = new JButton(退出);/按钮添加监听器jButton1.addActionListener(new ActionListener() public void actionPerformed(ActionEvent evt) jButton1ActionPerformed(evt););/按钮添加监听器jButton2.addActio

9、nListener(new ActionListener() public void actionPerformed(ActionEvent evt) jButton2ActionPerformed(evt););/声明定义内容面板，并且设置其布局格式为：4行2列格子Container c = getContentPane();c.setLayout(new GridLayout(4, 2);/将8个组件加入到内容面板c.add(jLabel1);c.add(textOfRadius);c.add(jLabel2);c.add(jLabel3);c.add(jLabel4);c.add(jLa

10、bel5);c.add(jButton1);c.add(jButton2);/ 求周长方法private String Round(double a) double perimeter = a * 2 * 3.14;String s = new String(String.valueOf(perimeter);return s;/ 求面积方法private String Area(double a) double area = a * a * 3.14;String s = new String(String.valueOf(area);return s;/点击“计算”按钮jButton1触发

11、的方法private void jButton1ActionPerformed(ActionEvent evt) /捕获单文本输入非数字的异常try String s = textOfRadius.getText();/获得单文本字符double a = Double.valueOf(s).floatValue();/字符转化为双精度jLabel3.setText(Round(a);/标签内容为周长jLabel5.setText(Area(a);/标签内容为面积 catch (NumberFormatException r) /单文本为非数字弹出提示“输入错误”框JOptionPane.sho

12、wMessageDialog(this, 请输入数字类型, 输入错误,JOptionPane.WARNING_MESSAGE);textOfRadius.setText();/点击“退出”按钮jButton2触发的方法public void jButton2ActionPerformed(ActionEvent evt) System.exit(0);运行结果：编译text9_3.java产生字节码文件test9_3.class，接下来需要编写一个HTML文件text9_3.html来嵌入text9_3.class，代码如下：将test9_3.html文件和test9_3.class文件放在同

13、一个目录下，在浏览器中打开这个test9_3.html文件，实现的效果如下：4.编写一个Applet，向其输入五个数，然后以条形图（bar graph）的形式来表示这些数。（还没完善好，供参考）/MyJPanel类import java.awt.Graphics;import javax.swing.JPanel;public class MyJPanel extends JPanelpublic int shu=new int5;public MyJPanel(int shu)for(int i=0;i5;i+)this.shui=shui;this.setSize(200, 200);th

14、is.setVisible(true);public void paint(Graphics g)/Componentsuper.paint(g);for(int i=0;i5;i+)g.fillRect(10, 30*i, 10*shui, 20);/test9_4import java.awt.GridLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.JButton;import javax.swing.JFrame;import javax.sw

15、ing.JPanel;import javax.swing.JTextField;public class test9_4 extends JFrame implements ActionListener JFrame jFrame;JTextField jTextField1;JTextField jTextField2;JTextField jTextField3;JTextField jTextField4;JTextField jTextField5;JButton jButton;int number=1,2,3,4,5;JPanel jPanel1;MyJPanel jPanel2

16、;public void init() JFrame jFrame = new JFrame(条形图表示数);jFrame.setSize(600, 210);/ jFrame.setResizable(false);jFrame.setLayout(new GridLayout(1,2);jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);jTextField1 = new JTextField();jTextField2 = new JTextField();jTextField3 = new JTextField();jTextFi

17、eld4 = new JTextField();jTextField5 = new JTextField();jButton = new JButton(开始);jButton.addActionListener(this);jPanel1 = new JPanel();jPanel1.setLayout(new GridLayout(6, 1);jPanel1.add(jTextField1);jPanel1.add(jTextField2);jPanel1.add(jTextField3);jPanel1.add(jTextField4);jPanel1.add(jTextField5);

18、jPanel1.add(jButton);jPanel2=new MyJPanel(number);jFrame.add(jPanel1);jFrame.add(jPanel2);jFrame.pack();jFrame.setVisible(true);Overridepublic void actionPerformed(ActionEvent e) / TODO Auto-generated method stubnumber0=Integer.parseInt(jTextField1.getText();number1=Integer.parseInt(jTextField2.getT

19、ext();number2=Integer.parseInt(jTextField3.getText();number3=Integer.parseInt(jTextField4.getText();number4=Integer.parseInt(jTextField5.getText();for(int i=0;i5;i+)System.out.println(numberi);public static void main(String args) new test9_4().init();5.编写一个绘制圆形的程序，当鼠标在绘制区域中单击时，该正方形的左上角顶点应准确的跟随鼠标光标移动

20、，重绘该圆形。/MyJFrame类import java.awt.Graphics;import java.awt.event.MouseEvent;import java.awt.event.MouseListener;import javax.swing.JFrame;public class MyJFrame extends JFrame implements MouseListenerint x=50;int y=50;int radius=50;public MyJFrame()this.setTitle(绘制圆形);this.setSize(200,200);this.setRes

21、izable(false);this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);this.addMouseListener(this);this.setVisible(true);public void paint(Graphics g)g.drawOval(x, y, radius, radius);public void mouseClicked(MouseEvent e) / TODO Auto-generated method stubthis.x=e.getX();this.y=e.getY();this.repaint();Sys

22、tem.out.println(x: + e.getX() + ny: + e.getY();public void mouseEntered(MouseEvent e) / TODO Auto-generated method stubpublic void mouseExited(MouseEvent e) / TODO Auto-generated method stubpublic void mousePressed(MouseEvent e) / TODO Auto-generated method stubpublic void mouseReleased(MouseEvent e

23、) / TODO Auto-generated method stubpublic static void main(String args)new MyJFrame();运行结果：6.编写一个“猜数”程序：该程序随机在1到100的范围内选择一个供用户猜测的整数，然后改程序显示提示信息，要求用户输入一个1到100之间的整数，根据输入偏大、偏小、正确，程序将显示不同的图标。/GuessNumber类import java.awt.GridLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;im

24、port java.util.Random;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JOptionPane;import javax.swing.JTextField;import javax.swing.SwingConstants;public class GuessNumber extends JFrame implements ActionListener int numberOfRandom;/ 游戏程序随机数int number

25、OfUser;/ 玩家输入整数JLabel label1;/ 标签1：“输入一个1到100之间的整数”JLabel label2;/ 标签2：“提示”JLabel label3;/ 标签3：提示的内容（偏大、偏小、正确）JButton buttonOfSure;/ 确定按钮JButton buttonOfExit;/ 退出按钮JTextField jTextField;/ 猜数输入单行文本框public void init() / 窗体的定义this.setTitle(这是一个猜数游戏);this.setSize(400, 120);this.setResizable(false);this.

26、setLayout(new GridLayout(3, 2);this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);/ 随机数Random random = new Random();numberOfRandom = random.nextInt(100);/ 各组件的定义label1 = new JLabel(请输入一个1到100之间的整数：);label2 = new JLabel(提示：, SwingConstants.CENTER);label3 = new JLabel(猜猜看);buttonOfSure = new JButton(

27、确定);this.getRootPane().setDefaultButton(buttonOfSure);/ 默认用户按下回车键触发“确定”按钮buttonOfSure.addActionListener(this);buttonOfExit = new JButton(退出);buttonOfExit.addActionListener(this);jTextField = new JTextField(输入);/ 窗体加入各组件this.add(label1);this.add(jTextField);this.add(label2);this.add(label3);this.add(buttonOfSure);this.add(buttonOfExit);/ 显示窗体this.setVisible(true);System.out.println(numberOfRandom);/ 偷偷看看随机数，哈哈/ 事件处理pu