201871010136—赵艳强《面向对象程序设计（java）》第十三周学习总结
内容导读
互联网集市收集整理的这篇技术教程文章主要介绍了201871010136—赵艳强《面向对象程序设计（java）》第十三周学习总结，小编现在分享给大家，供广大互联网技能从业者学习和参考。文章包含36458字，纯文字阅读大概需要53分钟。
内容图文
201871010136—赵艳强《面向对象程序设计（java）》第十三周学习总结
?博文正文开头格式：（2分）
|
项目 |
内容 |
|
《面向对象程序设计（java）》 |
https://www.cnblogs.com/nwnu-daizh/ |
|
这个作业的要求在哪里 |
https://www.cnblogs.com/nwnu-daizh/p/11888568.html |
|
作业学习目标 |
(1) 掌握事件处理的基本原理，理解其用途； (2) 掌握AWT事件模型的工作机制； (3) 掌握事件处理的基本编程模型； (4) 了解GUI界面组件观感设置方法； (5) 掌握WindowAdapter类、AbstractAction类的用法； (6) 掌握GUI程序中鼠标事件处理技术。 |
随笔博文正文内容包括：
第一部分：总结第十一章理论知识（35分）
第11章 事件处理
一、 事件处理基础
（a)事件源（event source）：能够产生事件的对象都可 以成为事件源，如文本框、按钮等。一个事件源是一个 能够注册监听器并向监听器发送事件对象的对象。
（b) 事件监听器（event listener）：事件监听器对象接 收事件源发送的通告（事件对象），并对发生的事件作 出响应。一个监听器对象就是一个实现了专门监听器接 口的类实例，该类必须实现接口中的方法，这些方法当 事件发生时,被自动执行。
（c) 事件对象（event object）：Java将事件的相关信息 封装在一个事件对象中，所有的事件对象都最终派生于 java.util.EventObject类。不同的事件源可以产生不 同类别的事件。
（d）监听器对象:是一个实现了特定监听器接口的类实例。
（e）GUI设计：GUI设计中，程序员需要对组件的某种事件进行响应和处理时，必须完成两个步骤：
1) 定义实现某事件监听器接口的事件监听器类，并具体化接口中声明的事件处理抽象方法。
2) 为组件注册实现了规定接口的事件监听器对象；
（f）注册监听器方法：eventSourceObject.addEventListener(eventListenerObject)
（g）监听器接口的实现：监听器类必须实现与事件源相对应的接口，即必须提供接口中方法的实现。
（h）适配器类：当程序用户试图关闭一个框架窗口时，Jframe对象就是WindowEvent的事件源。
适配器类动态地满足了Java中实现监视器类的技术要求。
通过扩展适配器类来实现窗口事件需要的动作。
处理按钮点击事件：对于GUI的应用程序来说，事件处理是必不可少的，因此我们需要熟练地掌握事件处理模型。对于事件我们需要了解两个名词：事件源对象与监听器对象。从字面上我们就可以理解个大概，下面我们系统说明一下：监听器对象是一个实现了特定监听器接口（listener interface）的类的实例，事件源是一个能够注册监听器对象并发送事件对象的对象，事件发生时，事件源将事件对象传递给所有注册的监听器，监听器对象将利用事件对象中的信息决定如何对事件做出相应
二、简洁的指定监听器
监听器对象就是一个实现了特定监听器接口的类的实例，那么监听器接口就是我们所关心的问题了。在监听器接口的最顶层接口是java.util.EventListener,这个接口是所有事件侦听器接口必须扩展的标记接口。感到诧异的是这个接口完全是空的，里面没有任何的抽象方法的定义，查看源代码里面空空如也啊！
事件监听器类（监听器对象所属的类）必须实现事件监听器接口或继承事件监听器适配器类。
事件监听器接口定义了处理事件必须实现的方法。
事件监听器适配器类是对事件监听器接口的简单实现。目的是为了减少编程的工作量。
??事件监听器的接口命名方式为：XXListener，而且，在java中，这些接口已经被定义好了。用来被实现，它定义了事件处理器（即事件处理的方法原型，这个方法需要被重新实现）。
例如：ActionListener接口、MouseListener接口、WindowListener接口、KeyListener接口、ItemListener接口、MouseMotionListener接口、FocusListener接口、ComponentListener接口等
三、改变观感
Swing程序默认使用Metal观感，采用两种方式改变观感。
第一种：在Java安装的子目录jre/lib下的文件swing.properties中，将属性swing.defaultlaf设置为所希望的观感类名。
swing.defaultlaf=com.sun.java.swing.plaf.motif.MotifLookAndFeel
第二种：调用静态的UIManager. setLookAndFeel方法，动态地改变观感，提供所想要的观感类名，再调用静态方法SwingUtilities.updateComponentTreeUI来刷新全部的组件集。
四、适配器类
1.当程序用户试图关闭一个框架窗口时，JFrame对象就是WindowEvent的事件源。
捕获窗口事件的监听器：WindowListener listener=...frame.addWindowListener(listener);
窗口监听器必须是实现WindowListener接口的类的一个对象，WindowListener接口中有七个方法，它们的名字是自解释的。
2.鉴于代码简化的要求，对于不止一个方法的AWT监听器接口都有一个实现了它的所有方法，但却不做任何工作的适配器类。例：WindowAdapter类。
适配器类动态地满足了Java中实现监视器类的技术要求。通过扩展适配器类来实现窗口事件需要的动作。
3.扩展WindowAdapter类，继承六个空方法，并覆盖WindowClosing（）方法：
class Terminator extends WindowAdapter{
public void windowClosing(WindowEvente){
System.exit(0);}}
4.可将一个Terminator对象注册为事件监听器：WindowListener listener=new Terminator();frame.addWindowListener(listener);
只要框架产生一个窗口事件，该事件就会传递给监听器对象。
创建扩展于WindowAdapter的监听器类是很好的改进，但还可以进一步将上面语句也可简化为：frame.addWindowListener(new Terminator());
五、动作
（a) 激活一个命令可以有多种方式，如用户可以通过 菜单、击键或工具栏上的按钮选择特定的功能。
（b) 在AWT事件模型中，无论是通过哪种方式下达命 令（如：点击按钮、菜单选项、按下键盘），其 操作动作都是一样的。
（c）动作接口及其类：Swing包提供了非常实用的机制来封装命令，并将它们连接到多个事件源，这就是Action接口。
（d）Action是一个接口，而不是一个类，实现这个接口的类必须要实现它的7个方法。
（e）AbstractAction 类 实 现 了 Action 接 口 中 除actionPerformed方法之外的所有方法，这个类存储了所有名/值对，并管理着属性变更监听器。
六、 鼠标事件
（a)鼠标事件 – MouseEvent
（b)鼠标监听器接口 – MouseListener – MouseMotionListener
（c) 鼠标监听器适配器 – MouseAdapter – MouseMotionAdapter
（d）用户点击鼠标按钮时,会调用三个监听器方法：
1.鼠标第一次被按下时调用mousePressed方法；
2.鼠标被释放时调用mouseReleased方法；
3.两个动作完成之后,调用mouseClicked方法。
（e）鼠标在组件上移动时,会调用mouseMoved方法。
（f）鼠标事件返回值:鼠标事件的类型是MouseEvent，当发生鼠标事件时：MouseEvent类自动创建一个事件对象，以及事件发生位置的x和y坐标，作为事件返回值。
（g）监听鼠标点击事件，实现MouseListener接口.
七、AWT事件继承层次
（a) 所有的事件都是由java.util包中的EventObject 类扩展而来。
（b) AWTEevent 是所有AWT 事件类的父类, 也是 EventObject的直接子类。
（c) 有些Swing组件生成其他类型的事件对象,一般直 接 扩 展 于 EventObject, 而不是AWTEvent,位于 javax.swing.event.*。
（d) 事件对象封装了事件源与监听器彼此通信的事件 信息。在必要的时候,可以对传递给监听器对象的 事件对象进行分析。
第二部分：实验部分
实验1：测试程序1（5分）
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 |
package button;
?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
?
/**
?* A frame with a button panel
?*/
public class ButtonFrame?extends JFrame
{
???private JPanel buttonPanel;
???private static final int DEFAULT_WIDTH =?300;
???private static final int DEFAULT_HEIGHT =?200;
?
???public ButtonFrame()
???{????
???????//调整组件的大小，宽度和高度
??????setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
?
??????// 创建了三个按钮对象
??????JButton yellowButton =?new JButton("Yellow");
??????JButton blueButton =?new JButton("Blue");
??????JButton redButton =?new JButton("Red");
?
??????buttonPanel =?new JPanel();
?
??????// 向面板添加按钮
??????buttonPanel.add(yellowButton);
??????buttonPanel.add(blueButton);
??????buttonPanel.add(redButton);
?
??????//将面板添加到框架
??????add(buttonPanel);
?
??????// 创建按钮对象
??????ColorAction yellowAction =?new ColorAction(Color.YELLOW);
??????ColorAction blueAction =?new ColorAction(Color.BLUE);
??????ColorAction redAction =?new ColorAction(Color.RED);
?
??????// 将动作与按钮相关联
??????yellowButton.addActionListener(yellowAction);
??????blueButton.addActionListener(blueAction);
??????redButton.addActionListener(redAction);
???}
?
???/**
????* An action listener that sets the panel's background color.
????*/
???private class ColorAction?implements ActionListener
???//ColorAction类后面实现了一个监听器接口类ActionListener
???{
??????private Color backgroundColor;
?//Color 类用于封装默认 sRGB 颜色空间中的颜色，或者用于封装由 ColorSpace 标识的任意颜色空间中的颜色
?
??????public ColorAction(Color c)
??????{
?????????backgroundColor = c;
??????}
?
??????public void actionPerformed(ActionEvent event)
??????{
?????????buttonPanel.setBackground(backgroundColor);
??????}
???}
}
|
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 |
package button;
?
import java.awt.*;
import javax.swing.*;
?
/**
?* @version 1.34 2015-06-12
?* @author Cay Horstmann
?*/
public class ButtonTest
{
???public static void main(String[] args)
???{
???????//lambda表达式
??????EventQueue.invokeLater(() -> {
?????????JFrame frame =?new ButtonFrame();
?????????frame.setTitle("ButtonTest");
?????????//setTitle表示将此窗体的标题设置为制定的字符串
?????????frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
?????????//根据参数的值显示或隐藏窗口
?????????frame.setVisible(true);
??????});
???}
}
|
用lambda表达式简化：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 |
package button;
?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
?
/**
?* A frame with a button panel
?*/
public class ButtonFrame?extends JFrame {
????private JPanel buttonPanel;
????private static final int DEFAULT_WIDTH =?300*2;
????private static final int DEFAULT_HEIGHT =?200*2;
?
????public ButtonFrame() {
????????setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
????????//用new运算符调用构造器
????????buttonPanel =?new JPanel();
????//创建按钮生成了三个按钮对象
????????makeButton("黄色", Color.yellow);
????????makeButton("蓝色", Color.blue);
????????makeButton("红色", Color.red);
????????add(buttonPanel);
????}
????protected void makeButton(String name,Color backgound) {
????????// 创建按钮
????????JButton button =?new JButton(name);
????????// 向面板添加按钮
????????buttonPanel.add(button);
????????// 创建按钮操作
????????
????????button.addActionListener(new ActionListener() {
?????????????
????????????public void actionPerformed(ActionEvent e) {
????????????????// TODO 自动生成的方法存根
????????????????buttonPanel.setBackground(backgound);
????????????}
????????});
????????//通过lambad表达式实现
????????button.addActionListener((e)->{
????????????buttonPanel.setBackground(backgound);
????????});???
????}??
}
|
运行结果如下：
测试程序2：
1） 在elipse IDE中调试运行教材449页程序11-2，结合程序运行结果理解程序；
2） 在组件观感设置代码处添加注释；
3） 了解GUI程序中观感的设置方法。
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 |
import java.awt.*;
import javax.swing.*;
/**
?* @version 1.32 2015-06-12
?* @author Cay Horstmann
?*/
public class PlafTest
{
???public static void main(String[] args)
???{
??????EventQueue.invokeLater(() -> {
?????????JFrame frame =?new PlafFrame();
?????????frame.setTitle("PlafTest");
?????????frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
?????????frame.setVisible(true);
??????});
???}
|
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 |
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
/**
?* 带有按钮面板的框架，用于更改外观和感觉
?*/
public class PlafFrame?extends JFrame
{
???private JPanel buttonPanel;
???public PlafFrame()//构造器
???{
??????buttonPanel =?new JPanel();
??????UIManager.LookAndFeelInfo[] infos = UIManager.getInstalledLookAndFeels();
??????for (UIManager.LookAndFeelInfo info : infos)
?????????makeButton(info.getName(), info.getClassName());
??????add(buttonPanel);
??????pack();
???}
???/**
????* 创建一个按钮来更改可插入的外观.
????* @param name the button name
????* @param className the name of the look-and-feel class
????*/
???private void makeButton(String name, String className)
???{
??????//添加按钮到面板
??????JButton button =?new JButton(name);
??????buttonPanel.add(button);
??????//设置按钮要进行的操作
??????button.addActionListener(event -> {
?????????// 按钮操作结果: 切换到新的外观
?????????try //可能出错的代码放入try子句中
?????????{
????????????UIManager.setLookAndFeel(className);
????????????SwingUtilities.updateComponentTreeUI(this);
????????????pack();
?????????}
?????????catch (Exception e)
?????????{
????????????e.printStackTrace();
?????????}
??????});
???}
}
|
运行结果：
测试程序3：
1）在elipse IDE中调试运行教材457页-458页程序11-3，结合程序运行结果理解程序；
2）掌握AbstractAction类及其动作对象；
3）掌握GUI程序中按钮、键盘动作映射到动作对象的方法。
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 |
package action;
import java.awt.*;
import javax.swing.*;
/**
?* @version 1.34 2015-06-12
?* @author Cay Horstmann
?*/
public class ActionTest
{
???public static void main(String[] args)
???{
??????EventQueue.invokeLater(() -> {//lamda表达式
?????????var frame =?new ActionFrame();
?????????frame.setTitle("ActionTest");//设置标题
?????????frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//设置关闭操作
?????????frame.setVisible(true);//设置可见性
??????});
???}
}
|
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 |
package action;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
/**
?* A frame with a panel that demonstrates color change actions.
?*/
public class ActionFrame?extends JFrame//继承关系，ActionFrame的父类JFrame
{
???private JPanel buttonPanel;
???private static final int DEFAULT_WIDTH =?300;
???private static final int DEFAULT_HEIGHT =?200;
???public ActionFrame()//构造器
???{
??????setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
??????buttonPanel =?new JPanel();
??????// 定义按钮
??????var yellowAction =?new ColorAction("Yellow",?new ImageIcon("yellow-ball.gif"),
????????????Color.YELLOW);
??????var blueAction =?new ColorAction("Blue",?new ImageIcon("blue-ball.gif"), Color.BLUE);
??????var redAction =?new ColorAction("Red",?new ImageIcon("red-ball.gif"), Color.RED);
??????// add buttons for these actions
??????buttonPanel.add(new JButton(yellowAction));
??????buttonPanel.add(new JButton(blueAction));
??????buttonPanel.add(new JButton(redAction));
??????// add panel to frame
??????add(buttonPanel);
?????// 将Y、B和R键与名称关联起来
??????InputMap inputMap = buttonPanel.getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
??????inputMap.put(KeyStroke.getKeyStroke("ctrl Y"),?"panel.yellow");
??????inputMap.put(KeyStroke.getKeyStroke("ctrl B"),?"panel.blue");
??????inputMap.put(KeyStroke.getKeyStroke("ctrl R"),?"panel.red");
??????// associate the names with actions
??????ActionMap actionMap = buttonPanel.getActionMap();
??????actionMap.put("panel.yellow", yellowAction);
??????actionMap.put("panel.blue", blueAction);
??????actionMap.put("panel.red", redAction);
???}
???
???public class ColorAction?extends AbstractAction
???{
??????/**
???????* Constructs a color action.
???????* @param name the name to show on the button
???????* @param icon the icon to display on the button
???????* @param c the background color
???????*/
??????public ColorAction(String name, Icon icon, Color c)
??????{
?????????putValue(Action.NAME, name);
?????????putValue(Action.SMALL_ICON, icon);
?????????putValue(Action.SHORT_DESCRIPTION,?"Set panel color to " + name.toLowerCase());
?????????putValue("color", c);
??????}
??????public void actionPerformed(ActionEvent event)
??????{
?????????var color = (Color) getValue("color");
?????????buttonPanel.setBackground(color);
??????}
???}
}
|
程序运行时只需同时按Ctrl+Y或R或B键，窗口就会自动显示某种颜色，运行结果如下：
测试程序4：
● 在elipse IDE中调试运行教材462页程序11-4、11-5，结合程序运行结果理解程序；
● 掌握GUI程序中鼠标事件处理技术。
代码如下：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 |
package mouse;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;
/**
?* 带有鼠标操作的用于添加和删除正方形的组件。
?*/
public class MouseComponent?extends JComponent
{
???private static final int DEFAULT_WIDTH =?300;
???private static final int DEFAULT_HEIGHT =?200;
???private static final int SIDELENGTH =?10;
???private ArrayList<Rectangle2D> squares;
???private Rectangle2D current;?//包含鼠标光标的正方形
???public MouseComponent()
???{
??????squares =?new ArrayList<>();
??????current =?null;
??????addMouseListener(new MouseHandler());
??????addMouseMotionListener(new MouseMotionHandler());
???}
???public Dimension getPreferredSize()
???{
??????return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT);
???}??
???
???public void paintComponent(Graphics g)
???{
??????var g2 = (Graphics2D) g;
???// 遍历正方形集合，并将每个正方形绘制出来
??????for (Rectangle2D r : squares)
?????????g2.draw(r);
???}
???/**
????* Finds the first square containing a point.
????* @param p a point
????* @return the first square that contains p
????*/
???public Rectangle2D find(Point2D p)
???{
??????for (Rectangle2D r : squares)
??????{
?????????if (r.contains(p))?return r;
??????}
??????return null;
???}
???/**
????* Adds a square to the collection.
????* @param p the center of the square
????*/
???public void add(Point2D p)
???{
??????double x = p.getX();
??????double y = p.getY();
??????current =?new Rectangle2D.Double(x - SIDELENGTH /?2, y - SIDELENGTH /?2,
?????????SIDELENGTH, SIDELENGTH);
??????squares.add(current);
??????repaint();
???}
???/**
????* Removes a square from the collection.
????* @param s the square to remove
????*/
???public void remove(Rectangle2D s)
???{
??????if (s ==?null)?return;
??????if (s == current) current =?null;
??????squares.remove(s);
??????repaint();
???}
???private class MouseHandler?extends MouseAdapter
???{
??????public void mousePressed(MouseEvent event)
??????{
?????????// add a new square if the cursor isn't inside a square
?????????current = find(event.getPoint());
?????????if (current ==?null) add(event.getPoint());
??????}
??????public void mouseClicked(MouseEvent event)
??????{
??????????//如果光标所在位置在正方形集合中包含并且鼠标点击次数>=2，则删除此位置的正方形
?????????current = find(event.getPoint());
?????????if (current !=?null && event.getClickCount() >=?2) remove(current);
??????}
???}
???private class MouseMotionHandler?implements MouseMotionListener
???{
????
??????public void mouseMoved(MouseEvent event)
??????{
?????????// set the mouse cursor to cross hairs if it is inside a rectangle
?????????if (find(event.getPoint()) ==?null) setCursor(Cursor.getDefaultCursor());
?????????else setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
??????}
??????public void mouseDragged(MouseEvent event)
??????{
?????????if (current !=?null)
?????????{
????????????int x = event.getX();
????????????int y = event.getY();
?????????// 拖动当前矩形使其居中（x，y）
????????????current.setFrame(x - SIDELENGTH /?2, y - SIDELENGTH /?2, SIDELENGTH, SIDELENGTH);
????????????repaint();
?????????}
??????}
???}??
}
|
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
package mouse;
import javax.swing.*;
/**
?* A frame containing a panel for testing mouse operations
?*/
public class MouseFrame?extends JFrame
{
???public MouseFrame()
???{
??????add(new MouseComponent());
??????pack();
???}
}
|
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 |
package mouse;
import java.awt.*;
import javax.swing.*;
/**
?* @version 1.35 2018-04-10
?* @author Cay Horstmann
?*/
public class MouseTest
{
???public static void main(String[] args)
???{
??????EventQueue.invokeLater(() -> {
?????????var frame =?new MouseFrame();
?????????frame.setTitle("MouseTest");
?????????frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
?????????frame.setVisible(true);
??????});
???}
}
|
运行结果如下：
学习总结：
通过本周的学习，我知道了如何进行事件处理，
测试程序4：
● 在elipse IDE中调试运行教材462页程序11-4、11-5，结合程序运行结果理解程序；
● 掌握GUI程序中鼠标事件处理技术。
代码如下：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 |
package mouse;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;
/**
?* 带有鼠标操作的用于添加和删除正方形的组件。
?*/
public class MouseComponent?extends JComponent
{
???private static final int DEFAULT_WIDTH =?300;
???private static final int DEFAULT_HEIGHT =?200;
???private static final int SIDELENGTH =?10;
???private ArrayList<Rectangle2D> squares;
???private Rectangle2D current;?//包含鼠标光标的正方形
???public MouseComponent()
???{
??????squares =?new ArrayList<>();
??????current =?null;
??????addMouseListener(new MouseHandler());
??????addMouseMotionListener(new MouseMotionHandler());
???}
???public Dimension getPreferredSize()
???{
??????return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT);
???}??
???
???public void paintComponent(Graphics g)
???{
??????var g2 = (Graphics2D) g;
???// 遍历正方形集合，并将每个正方形绘制出来
??????for (Rectangle2D r : squares)
?????????g2.draw(r);
???}
???/**
????* Finds the first square containing a point.
????* @param p a point
????* @return the first square that contains p
????*/
???public Rectangle2D find(Point2D p)
???{
??????for (Rectangle2D r : squares)
??????{
?????????if (r.contains(p))?return r;
??????}
??????return null;
???}
???/**
????* Adds a square to the collection.
????* @param p the center of the square
????*/
???public void add(Point2D p)
???{
??????double x = p.getX();
??????double y = p.getY();
??????current =?new Rectangle2D.Double(x - SIDELENGTH /?2, y - SIDELENGTH /?2,
?????????SIDELENGTH, SIDELENGTH);
??????squares.add(current);
??????repaint();
???}
???/**
????* Removes a square from the collection.
????* @param s the square to remove
????*/
???public void remove(Rectangle2D s)
???{
??????if (s ==?null)?return;
??????if (s == current) current =?null;
??????squares.remove(s);
??????repaint();
???}
???private class MouseHandler?extends MouseAdapter
???{
??????public void mousePressed(MouseEvent event)
??????{
?????????// add a new square if the cursor isn't inside a square
?????????current = find(event.getPoint());
?????????if (current ==?null) add(event.getPoint());
??????}
??????public void mouseClicked(MouseEvent event)
??????{
??????????//如果光标所在位置在正方形集合中包含并且鼠标点击次数>=2，则删除此位置的正方形
?????????current = find(event.getPoint());
?????????if (current !=?null && event.getClickCount() >=?2) remove(current);
??????}
???}
???private class MouseMotionHandler?implements MouseMotionListener
???{
????
??????public void mouseMoved(MouseEvent event)
??????{
?????????// set the mouse cursor to cross hairs if it is inside a rectangle
?????????if (find(event.getPoint()) ==?null) setCursor(Cursor.getDefaultCursor());
?????????else setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
??????}
??????public void mouseDragged(MouseEvent event)
??????{
?????????if (current !=?null)
?????????{
????????????int x = event.getX();
????????????int y = event.getY();
?????????// 拖动当前矩形使其居中（x，y）
????????????current.setFrame(x - SIDELENGTH /?2, y - SIDELENGTH /?2, SIDELENGTH, SIDELENGTH);
????????????repaint();
?????????}
??????}
???}??
}
|
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
package mouse;
import javax.swing.*;
/**
?* A frame containing a panel for testing mouse operations
?*/
public class MouseFrame?extends JFrame
{
???public MouseFrame()
???{
??????add(new MouseComponent());
??????pack();
???}
}
|
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 |
package mouse;
import java.awt.*;
import javax.swing.*;
/**
?* @version 1.35 2018-04-10
?* @author Cay Horstmann
?*/
public class MouseTest
{
???public static void main(String[] args)
???{
??????EventQueue.invokeLater(() -> {
?????????var frame =?new MouseFrame();
?????????frame.setTitle("MouseTest");
?????????frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
?????????frame.setVisible(true);
??????});
???}
}
|
运行结果如下：
测试程序4：
● 在elipse IDE中调试运行教材462页程序11-4、11-5，结合程序运行结果理解程序；
● 掌握GUI程序中鼠标事件处理技术。
代码如下：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 |
package mouse;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;
/**
?* 带有鼠标操作的用于添加和删除正方形的组件。
?*/
public class MouseComponent?extends JComponent
{
???private static final int DEFAULT_WIDTH =?300;
???private static final int DEFAULT_HEIGHT =?200;
???private static final int SIDELENGTH =?10;
???private ArrayList<Rectangle2D> squares;
???private Rectangle2D current;?//包含鼠标光标的正方形
???public MouseComponent()
???{
??????squares =?new ArrayList<>();
??????current =?null;
??????addMouseListener(new MouseHandler());
??????addMouseMotionListener(new MouseMotionHandler());
???}
???public Dimension getPreferredSize()
???{
??????return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT);
???}??
???
???public void paintComponent(Graphics g)
???{
??????var g2 = (Graphics2D) g;
???// 遍历正方形集合，并将每个正方形绘制出来
??????for (Rectangle2D r : squares)
?????????g2.draw(r);
???}
???/**
????* Finds the first square containing a point.
????* @param p a point
????* @return the first square that contains p
????*/
???public Rectangle2D find(Point2D p)
???{
??????for (Rectangle2D r : squares)
??????{
?????????if (r.contains(p))?return r;
??????}
??????return null;
???}
???/**
????* Adds a square to the collection.
????* @param p the center of the square
????*/
???public void add(Point2D p)
???{
??????double x = p.getX();
??????double y = p.getY();
??????current =?new Rectangle2D.Double(x - SIDELENGTH /?2, y - SIDELENGTH /?2,
?????????SIDELENGTH, SIDELENGTH);
??????squares.add(current);
??????repaint();
???}
???/**
????* Removes a square from the collection.
????* @param s the square to remove
????*/
???public void remove(Rectangle2D s)
???{
??????if (s ==?null)?return;
??????if (s == current) current =?null;
??????squares.remove(s);
??????repaint();
???}
???private class MouseHandler?extends MouseAdapter
???{
??????public void mousePressed(MouseEvent event)
??????{
?????????// add a new square if the cursor isn't inside a square
?????????current = find(event.getPoint());
?????????if (current ==?null) add(event.getPoint());
??????}
??????public void mouseClicked(MouseEvent event)
??????{
??????????//如果光标所在位置在正方形集合中包含并且鼠标点击次数>=2，则删除此位置的正方形
?????????current = find(event.getPoint());
?????????if (current !=?null && event.getClickCount() >=?2) remove(current);
??????}
???}
???private class MouseMotionHandler?implements MouseMotionListener
???{
????
??????public void mouseMoved(MouseEvent event)
??????{
?????????// set the mouse cursor to cross hairs if it is inside a rectangle
?????????if (find(event.getPoint()) ==?null) setCursor(Cursor.getDefaultCursor());
?????????else setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
??????}
??????public void mouseDragged(MouseEvent event)
??????{
?????????if (current !=?null)
?????????{
????????????int x = event.getX();
????????????int y = event.getY();
?????????// 拖动当前矩形使其居中（x，y）
????????????current.setFrame(x - SIDELENGTH /?2, y - SIDELENGTH /?2, SIDELENGTH, SIDELENGTH);
????????????repaint();
?????????}
??????}
???}??
}
|
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
package mouse;
import javax.swing.*;
/**
?* A frame containing a panel for testing mouse operations
?*/
public class MouseFrame?extends JFrame
{
???public MouseFrame()
???{
??????add(new MouseComponent());
??????pack();
???}
}
|
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 |
package mouse;
import java.awt.*;
import javax.swing.*;
/**
?* @version 1.35 2018-04-10
?* @author Cay Horstmann
?*/
public class MouseTest
{
???public static void main(String[] args)
???{
??????EventQueue.invokeLater(() -> {
?????????var frame =?new MouseFrame();
?????????frame.setTitle("MouseTest");
?????????frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
?????????frame.setVisible(true);
??????});
???}
}
|
运行结果如下：
测试程序4：
● 在elipse IDE中调试运行教材462页程序11-4、11-5，结合程序运行结果理解程序；
● 掌握GUI程序中鼠标事件处理技术。
代码如下：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 |
package mouse;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;
/**
?* 带有鼠标操作的用于添加和删除正方形的组件。
?*/
public class MouseComponent?extends JComponent
{
???private static final int DEFAULT_WIDTH =?300;
???private static final int DEFAULT_HEIGHT =?200;
???private static final int SIDELENGTH =?10;
???private ArrayList<Rectangle2D> squares;
???private Rectangle2D current;?//包含鼠标光标的正方形
???public MouseComponent()
???{
??????squares =?new ArrayList<>();
??????current =?null;
??????addMouseListener(new MouseHandler());
??????addMouseMotionListener(new MouseMotionHandler());
???}
???public Dimension getPreferredSize()
???{
??????return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT);
???}??
???
???public void paintComponent(Graphics g)
???{
??????var g2 = (Graphics2D) g;
???// 遍历正方形集合，并将每个正方形绘制出来
??????for (Rectangle2D r : squares)
?????????g2.draw(r);
???}
???/**
????* Finds the first square containing a point.
????* @param p a point
????* @return the first square that contains p
????*/
???public Rectangle2D find(Point2D p)
???{
??????for (Rectangle2D r : squares)
??????{
?????????if (r.contains(p))?return r;
??????}
??????return null;
???}
???/**
????* Adds a square to the collection.
????* @param p the center of the square
????*/
???public void add(Point2D p)
???{
??????double x = p.getX();
??????double y = p.getY();
??????current =?new Rectangle2D.Double(x - SIDELENGTH /?2, y - SIDELENGTH /?2,
?????????SIDELENGTH, SIDELENGTH);
??????squares.add(current);
??????repaint();
???}
???/**
????* Removes a square from the collection.
????* @param s the square to remove
????*/
???public void remove(Rectangle2D s)
???{
??????if (s ==?null)?return;
??????if (s == current) current =?null;
??????squares.remove(s);
??????repaint();
???}
???private class MouseHandler?extends MouseAdapter
???{
??????public void mousePressed(MouseEvent event)
??????{
?????????// add a new square if the cursor isn't inside a square
?????????current = find(event.getPoint());
?????????if (current ==?null) add(event.getPoint());
??????}
??????public void mouseClicked(MouseEvent event)
??????{
??????????//如果光标所在位置在正方形集合中包含并且鼠标点击次数>=2，则删除此位置的正方形
?????????current = find(event.getPoint());
?????????if (current !=?null && event.getClickCount() >=?2) remove(current);
??????}
???}
???private class MouseMotionHandler?implements MouseMotionListener
???{
????
??????public void mouseMoved(MouseEvent event)
??????{
?????????// set the mouse cursor to cross hairs if it is inside a rectangle
?????????if (find(event.getPoint()) ==?null) setCursor(Cursor.getDefaultCursor());
?????????else setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
??????}
??????public void mouseDragged(MouseEvent event)
??????{
?????????if (current !=?null)
?????????{
????????????int x = event.getX();
????????????int y = event.getY();
?????????// 拖动当前矩形使其居中（x，y）
????????????current.setFrame(x - SIDELENGTH /?2, y - SIDELENGTH /?2, SIDELENGTH, SIDELENGTH);
????????????repaint();
?????????}
??????}
???}??
}
|
运行结果如下：
学习总结：
通过本次实验
测试程序4：
● 在elipse IDE中调试运行教材462页程序11-4、11-5，结合程序运行结果理解程序；
● 掌握GUI程序中鼠标事件处理技术。
代码如下：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 |
package mouse;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;
/**
?* 带有鼠标操作的用于添加和删除正方形的组件。
?*/
public class MouseComponent?extends JComponent
{
???private static final int DEFAULT_WIDTH =?300;
???private static final int DEFAULT_HEIGHT =?200;
???private static final int SIDELENGTH =?10;
???private ArrayList<Rectangle2D> squares;
???private Rectangle2D current;?//包含鼠标光标的正方形
???public MouseComponent()
???{
??????squares =?new ArrayList<>();
??????current =?null;
??????addMouseListener(new MouseHandler());
??????addMouseMotionListener(new MouseMotionHandler());
???}
???public Dimension getPreferredSize()
???{
??????return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT);
???}??
???
???public void paintComponent(Graphics g)
???{
??????var g2 = (Graphics2D) g;
???// 遍历正方形集合，并将每个正方形绘制出来
??????for (Rectangle2D r : squares)
?????????g2.draw(r);
???}
???/**
????* Finds the first square containing a point.
????* @param p a point
????* @return the first square that contains p
????*/
???public Rectangle2D find(Point2D p)
???{
??????for (Rectangle2D r : squares)
??????{
?????????if (r.contains(p))?return r;
??????}
??????return null;
???}
???/**
????* Adds a square to the collection.
????* @param p the center of the square
????*/
???public void add(Point2D p)
???{
??????double x = p.getX();
??????double y = p.getY();
??????current =?new Rectangle2D.Double(x - SIDELENGTH /?2, y - SIDELENGTH /?2,
?????????SIDELENGTH, SIDELENGTH);
??????squares.add(current);
??????repaint();
???}
???/**
????* Removes a square from the collection.
????* @param s the square to remove
????*/
???public void remove(Rectangle2D s)
???{
??????if (s ==?null)?return;
??????if (s == current) current =?null;
??????squares.remove(s);
??????repaint();
???}
???private class MouseHandler?extends MouseAdapter
???{
??????public void mousePressed(MouseEvent event)
??????{
?????????// add a new square if the cursor isn't inside a square
?????????current = find(event.getPoint());
?????????if (current ==?null) add(event.getPoint());
??????}
??????public void mouseClicked(MouseEvent event)
??????{
??????????//如果光标所在位置在正方形集合中包含并且鼠标点击次数>=2，则删除此位置的正方形
?????????current = find(event.getPoint());
?????????if (current !=?null && event.getClickCount() >=?2) remove(current);
??????}
???}
???private class MouseMotionHandler?implements MouseMotionListener
???{
????
??????public void mouseMoved(MouseEvent event)
??????{
?????????// set the mouse cursor to cross hairs if it is inside a rectangle
?????????if (find(event.getPoint()) ==?null) setCursor(Cursor.getDefaultCursor());
?????????else setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
??????}
??????public void mouseDragged(MouseEvent event)
??????{
?????????if (current !=?null)
?????????{
????????????int x = event.getX();
????????????int y = event.getY();
?????????// 拖动当前矩形使其居中（x，y）
????????????current.setFrame(x - SIDELENGTH /?2, y - SIDELENGTH /?2, SIDELENGTH, SIDELENGTH);
????????????repaint();
?????????}
??????}
???}??
}
|
?
运行结果如下：
学习总结：
通过本次实验，熟悉掌握了Java的异常机制，通过new一个数组，从而通过数组的下标取出内容，当下标不合法时就会出现数组下标越界异常，通过catch铺获异常，并对异常做出处理。这仅仅是对简单异常的处理，还须更进一步对异常熟悉，还要对字符串的练习和掌握。通过实验课上学长演示实验，再用lambda表达式以及匿名类等简化程序，希望以后在学长的帮助下能学的更好。
内容总结
以上是互联网集市为您收集整理的201871010136—赵艳强《面向对象程序设计（java）》第十三周学习总结全部内容，希望文章能够帮你解决201871010136—赵艳强《面向对象程序设计（java）》第十三周学习总结所遇到的程序开发问题。 如果觉得互联网集市技术教程内容还不错，欢迎将互联网集市网站推荐给程序员好友。
内容备注
版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 gblab@vip.qq.com 举报，一经查实，本站将立刻删除。
内容手机端
扫描二维码推送至手机访问。
来源：【匿名】