第十三周作业
本人学号:201771010138
姓名:邹丰蔚
《面向对象程序设计(java)》第十三周学习总结
1、实验目的与要求
(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。
实验1: 导入第11章示例程序,测试程序并进行代码注释。
测试程序1:
l 在elipse IDE中调试运行教材443页-444页程序11-1,结合程序运行结果理解程序;
l 在事件处理相关代码处添加注释;
l 用lambda表达式简化程序;
l 掌握JButton组件的基本API;
l 掌握Java中事件处理的基本编程模型。
ButtonTest: 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) { EventQueue.invokeLater(() -> { JFrame frame = new ButtonFrame(); frame.setTitle("ButtonTest"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }); } }
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ButtonFrame: 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() { setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
// create buttons JButton yellowButton = new JButton("Yellow"); JButton blueButton = new JButton("Blue"); JButton redButton = new JButton("Red");
buttonPanel = new JPanel();
// add buttons to panel buttonPanel.add(yellowButton); buttonPanel.add(blueButton); buttonPanel.add(redButton);
// add panel to frame add(buttonPanel);
// create button actions ColorAction yellowAction = new ColorAction(Color.YELLOW); ColorAction blueAction = new ColorAction(Color.BLUE); ColorAction redAction = new ColorAction(Color.RED);
// associate actions with buttons yellowButton.addActionListener(yellowAction); blueButton.addActionListener(blueAction); redButton.addActionListener(redAction); }
/** * An action listener that sets the panel's background color. */ private class ColorAction implements ActionListener { private Color backgroundColor;
public ColorAction(Color c) { backgroundColor = c; }
public void actionPerformed(ActionEvent event) { buttonPanel.setBackground(backgroundColor); } } }
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得出结果:
测试程序2:
l 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;
l 在组件观感设置代码处添加注释;
l 了解GUI程序中观感的设置方法。
PlafTest: package plaf;
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); }); } }
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PlafFrame: package plaf;
import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.SwingUtilities; import javax.swing.UIManager;
/** * A frame with a button panel for changing look-and-feel */ public class PlafFrame extends JFrame { private JPanel buttonPanel;
public PlafFrame() { buttonPanel = new JPanel();
UIManager.LookAndFeelInfo[] infos = UIManager.getInstalledLookAndFeels(); for (UIManager.LookAndFeelInfo info : infos) makeButton(info.getName(), info.getClassName());
add(buttonPanel); pack(); }
/** * Makes a button to change the pluggable look-and-feel. * @param name the button name * @param className the name of the look-and-feel class */ private void makeButton(String name, String className) { // add button to panel
JButton button = new JButton(name); buttonPanel.add(button);
// set button action
button.addActionListener(event -> { // button action: switch to the new look-and-feel try { UIManager.setLookAndFeel(className); SwingUtilities.updateComponentTreeUI(this); pack(); } catch (Exception e) { e.printStackTrace(); } }); } }
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得出结果:
测试程序3:
l 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;
l 掌握AbstractAction类及其动作对象;
l 掌握GUI程序中按钮、键盘动作映射到动作对象的方法。
ActionTest: 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(() -> { JFrame frame = new ActionFrame(); frame.setTitle("ActionTest"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }); } } |
ActionFrame: 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 { private JPanel buttonPanel; private static final int DEFAULT_WIDTH = 300; private static final int DEFAULT_HEIGHT = 200;
public ActionFrame() { setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
buttonPanel = new JPanel();
// define actions Action yellowAction = new ColorAction("Yellow", new ImageIcon("yellow-ball.gif"), Color.YELLOW); Action blueAction = new ColorAction("Blue", new ImageIcon("blue-ball.gif"), Color.BLUE); Action 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);
// associate the Y, B, and R keys with names InputMap imap = buttonPanel.getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT); imap.put(KeyStroke.getKeyStroke("ctrl Y"), "panel.yellow"); imap.put(KeyStroke.getKeyStroke("ctrl B"), "panel.blue"); imap.put(KeyStroke.getKeyStroke("ctrl R"), "panel.red");
// associate the names with actions ActionMap amap = buttonPanel.getActionMap(); amap.put("panel.yellow", yellowAction); amap.put("panel.blue", blueAction); amap.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) { Color c = (Color) getValue("color"); buttonPanel.setBackground(c); } } }
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得出结果:
测试程序4:
l 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;
l 掌握GUI程序中鼠标事件处理技术。
MouseTest: package mouse;
import java.awt.*; import javax.swing.*;
/** * @version 1.34 2015-06-12 * @author Cay Horstmann */ public class MouseTest { public static void main(String[] args) { EventQueue.invokeLater(() -> { JFrame frame = new MouseFrame(); frame.setTitle("MouseTest"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }); } }
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MouseFrame: 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(); } }
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MouseComponent: package mouse;
import java.awt.*; import java.awt.event.*; import java.awt.geom.*; import java.util.*; import javax.swing.*;
/** * A component with mouse operations for adding and removing squares. */ 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; // the square containing the mouse cursor
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) { Graphics2D g2 = (Graphics2D) g;
// draw all squares 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) { // remove the current square if double clicked 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();
// drag the current rectangle to center it at (x, y) current.setFrame(x - SIDELENGTH / 2, y - SIDELENGTH / 2, SIDELENGTH, SIDELENGTH); repaint(); } } } }
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得出结果:
实验2:结对编程练习
利用班级名单文件、文本框和按钮组件,设计一个有如下界面(图1)的点名器,要求用户点击开始按钮后在文本输入框随机显示2017级网络与信息安全班同学姓名,如图2所示,点击停止按钮后,文本输入框不再变换同学姓名,此同学则是被点到的同学姓名。
图1 点名器启动界面
图2 点名器点名界面
编程同伴:张季跃
共同编写修改程序如下:
编程同伴:张季跃
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得出结果:
总结:在本周试验中,我掌握了事件处理的基本原理,理解其用途,AWT事件模型的工作机制,事件处理的基本编程模型,了解了GUI界面组件观感设置方法,掌握了WindowAdapter类、AbstractAction类的用法以及GUI程序中鼠标事件处理技术。但是在结对编程环节当中,完全没有任何的思路,想了很久还是不知道从何下手。自己做出来一个,结果无法停止。