焦旭超 201771010109 《面对对象程序设计（java）》第十四周学习总结 第十三组

1、实验目的与要求

(1) 掌握GUI布局管理器用法；

(2) 掌握各类Java Swing组件用途及常用API；

2、实验内容和步骤

实验1： 导入第12章示例程序，测试程序并进行组内讨论。

测试程序1

l  在elipse IDE中运行教材479页程序12-1，结合运行结果理解程序；

l  掌握各种布局管理器的用法；

l  理解GUI界面中事件处理技术的用途。

l  在布局管理应用代码处添加注释；

代码：

package calculator;

import javax.swing.*;

/**
* A frame with a calculator panel.
*/
public class CalculatorFrame extends JFrame
{
public CalculatorFrame()
{
add(new CalculatorPanel());
pack();
}
}

CalculatorFrame

package calculator;

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

/**
* @version 1.34 2015-06-12
* @author Cay Horstmann
*/
public class Calculator
{
public static void main(String[] args)
{
EventQueue.invokeLater(() -> {
CalculatorFrame frame = new CalculatorFrame();
frame.setTitle("Calculator");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
});
}
}

Calculator

package calculator;

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

/**
* 具有计算器按钮和结果显示的面板
*/
public class CalculatorPanel extends JPanel {
private JButton display;
private JPanel panel;
private double result;
private String lastCommand;
private boolean start;

public CalculatorPanel() {
setLayout(new BorderLayout());

result = 0;
lastCommand = "=";
start = true;

// 添加display

display = new JButton("0");
display.setEnabled(false);
add(display, BorderLayout.NORTH);

ActionListener insert = new InsertAction();
ActionListener command = new CommandAction();

// 在4×4网格中添加按钮

panel = new JPanel();
panel.setLayout(new GridLayout(4, 4));

addButton("7", insert);
addButton("8", insert);
addButton("9", insert);
addButton("/", command);

addButton("4", insert);
addButton("5", insert);
addButton("6", insert);
addButton("*", command);

addButton("1", insert);
addButton("2", insert);
addButton("3", insert);
addButton("-", command);

addButton("0", insert);
addButton(".", insert);
addButton("=", command);
addButton("+", command);

add(panel, BorderLayout.CENTER);// 把面板添加在边框布局的中央
}

/**
* 向中心面板添加一个按钮
* 
* @param label the button label
* @param listener the button listener
*/
private void addButton(String label, ActionListener listener) {
JButton button = new JButton(label);
button.addActionListener(listener);
panel.add(button);
}

/**
* 此操作将按钮操作字符串插入到显示文本的末尾
*/
private class InsertAction implements ActionListener {
public void actionPerformed(ActionEvent event) {
String input = event.getActionCommand();// 标识此事件命令的字符串
if (start) {
display.setText("");
start = false;
}
display.setText(display.getText() + input);
}
}

/**
* 此操作执行按钮操作字符串所表示的命令
*/
private class CommandAction implements ActionListener {
public void actionPerformed(ActionEvent event) {
String command = event.getActionCommand();

if (start) {
if (command.equals("-"))// 负数的情况
{
display.setText(command);
start = false;
} else
lastCommand = command;
} else {
calculate(Double.parseDouble(display.getText()));// 把display中的string转换为double
lastCommand = command;
start = true;
}
}
}

/**
* 执行即将发生的计算
* 
* @param x值与先前结果一起累积。
*/
public void calculate(double x) {
if (lastCommand.equals("+"))
result += x;
else if (lastCommand.equals("-"))
result -= x;
else if (lastCommand.equals("*"))
result *= x;
else if (lastCommand.equals("/"))
result /= x;
else if (lastCommand.equals("="))
result = x;
display.setText("" + result);// 在double前添加""可转换为string
}
}

CalculatorPanel

测试程序2

l 在elipse IDE中调试运行教材486页程序12-2，结合运行结果理解程序；

l 掌握各种文本组件的用法；

l 记录示例代码阅读理解中存在的问题与疑惑。

package text;

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

/**
 * @version 1.41 2015-06-12
 * @author Cay Horstmann
 */
public class TextComponentTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() -> {
         JFrame frame = new TextComponentFrame();
         frame.setTitle("TextComponentTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

package text;

import java.awt.BorderLayout;
import java.awt.GridLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingConstants;

/**
 * 具有文本文本组件的框架.
 */
public class TextComponentFrame extends JFrame
{
   public static final int TEXTAREA_ROWS = 8;
   public static final int TEXTAREA_COLUMNS = 20;

   public TextComponentFrame()
   {
      JTextField textField = new JTextField();
      JPasswordField passwordField = new JPasswordField();

      JPanel northPanel = new JPanel();
      northPanel.setLayout(new GridLayout(2, 2));
      northPanel.add(new JLabel("User name: ", SwingConstants.RIGHT));
      northPanel.add(textField);
      northPanel.add(new JLabel("Password: ", SwingConstants.RIGHT));
      northPanel.add(passwordField);

      add(northPanel, BorderLayout.NORTH);

      JTextArea textArea = new JTextArea(TEXTAREA_ROWS, TEXTAREA_COLUMNS);
      JScrollPane scrollPane = new JScrollPane(textArea);

      add(scrollPane, BorderLayout.CENTER);

      // 添加按钮将文本追加到文本区域

      JPanel southPanel = new JPanel();

      JButton insertButton = new JButton("Insert");
      southPanel.add(insertButton);
      insertButton.addActionListener(event ->
         textArea.append("User name: " + textField.getText() + " Password: "
            + new String(passwordField.getPassword()) + "\n"));

      add(southPanel, BorderLayout.SOUTH);
      pack();
   }
}

测试程序3

1.在elipse IDE中调试运行教材489页程序12-3，结合运行结果理解程序；

2.掌握复选框组件的用法；

3.记录示例代码阅读理解中存在的问题与疑惑。

package checkBox;

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

/**
 * @version 1.34 2015-06-12
 * @author Cay Horstmann
 */
public class CheckBoxTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() -> {
         JFrame frame = new CheckBoxFrame();
         frame.setTitle("CheckBoxTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

package checkBox;

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

/**
 * 带有样本文本标签的框和用于选择字体的复选框
 * attributes.
 */
public class CheckBoxFrame extends JFrame
{
   private JLabel label;
   private JCheckBox bold;
   private JCheckBox italic;
   private static final int FONTSIZE = 24;

   public CheckBoxFrame()
   {
      // 添加示例文本标签

      label = new JLabel("The quick brown fox jumps over the lazy dog.");
      label.setFont(new Font("Serif", Font.BOLD, FONTSIZE));
      add(label, BorderLayout.CENTER);

      // 此侦听器设置字体属性
      // 到复选框状态的标签

      ActionListener listener = event -> {
         int mode = 0;
         if (bold.isSelected()) mode += Font.BOLD;
         if (italic.isSelected()) mode += Font.ITALIC;
         label.setFont(new Font("Serif", mode, FONTSIZE));
      };

      // 添加复选框

      JPanel buttonPanel = new JPanel();

      bold = new JCheckBox("Bold");
      bold.addActionListener(listener);
      bold.setSelected(true);
      buttonPanel.add(bold);

      italic = new JCheckBox("Italic");
      italic.addActionListener(listener);
      buttonPanel.add(italic);

      add(buttonPanel, BorderLayout.SOUTH);
      pack();
   }
}

测试程序4

1.在elipse IDE中调试运行教材491页程序12-4，运行结果理解程序；

2.掌握单选按钮组件的用法；

3.记录示例代码阅读理解中存在的问题与疑惑。

package radioButton;

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

/**
 * @version 1.34 2015-06-12
 * @author Cay Horstmann
 */
public class RadioButtonTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() -> {
         JFrame frame = new RadioButtonFrame();
         frame.setTitle("RadioButtonTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

package radioButton;

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

/**
 * 带有样本文本标签和单选按钮以选择字体大小的框架。
 */
public class RadioButtonFrame extends JFrame
{
   private JPanel buttonPanel;
   private ButtonGroup group;
   private JLabel label;
   private static final int DEFAULT_SIZE = 36;

   public RadioButtonFrame()
   {      
      // 添加示例文本标签

      label = new JLabel("The quick brown fox jumps over the lazy dog.");
      label.setFont(new Font("Serif", Font.PLAIN, DEFAULT_SIZE));
      add(label, BorderLayout.CENTER);

      // 添加单选按钮

      buttonPanel = new JPanel();
      group = new ButtonGroup();

      addRadioButton("Small", 8);
      addRadioButton("Medium", 12);
      addRadioButton("Large", 18);
      addRadioButton("Extra large", 36);

      add(buttonPanel, BorderLayout.SOUTH);
      pack();
   }

   /**
    * 添加一个设置示例文本字体大小的单选按钮。
    * @param 命名按钮上出现的字符串
    * @param 设置此按钮设置的字体大小
    */
   public void addRadioButton(String name, int size)
   {
      boolean selected = size == DEFAULT_SIZE;
      JRadioButton button = new JRadioButton(name, selected);
      group.add(button);
      buttonPanel.add(button);

      // 此侦听器设置标签字体大小。
      ActionListener listener = event -> label.setFont(new Font("Serif", Font.PLAIN, size));

      button.addActionListener(listener);
   }
}

测试程序5

1.在elipse IDE中调试运行教材494页程序12-5，结合运行结果理解程序；

2.掌握边框的用法；

3。记录示例代码阅读理解中存在的问题与疑惑。

package border;

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

/**
 * @version 1.34 2015-06-13
 * @author Cay Horstmann
 */
public class BorderTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() -> {
         JFrame frame = new BorderFrame();
         frame.setTitle("BorderTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

package border;

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

/**
 * 用单选按钮选择边框样式的框架
 */
public class BorderFrame extends JFrame
{
   private JPanel demoPanel;
   private JPanel buttonPanel;
   private ButtonGroup group;

   public BorderFrame()
   {
      demoPanel = new JPanel();
      buttonPanel = new JPanel();
      group = new ButtonGroup();

      addRadioButton("Lowered bevel", BorderFactory.createLoweredBevelBorder());
      addRadioButton("Raised bevel", BorderFactory.createRaisedBevelBorder());
      addRadioButton("Etched", BorderFactory.createEtchedBorder());
      addRadioButton("Line", BorderFactory.createLineBorder(Color.BLUE));
      addRadioButton("Matte", BorderFactory.createMatteBorder(10, 10, 10, 10, Color.BLUE));
      addRadioButton("Empty", BorderFactory.createEmptyBorder());

      Border etched = BorderFactory.createEtchedBorder();
      Border titled = BorderFactory.createTitledBorder(etched, "Border types");
      buttonPanel.setBorder(titled);

      setLayout(new GridLayout(2, 1));
      add(buttonPanel);
      add(demoPanel);
      pack();
   }

   public void addRadioButton(String buttonName, Border b)
   {
      JRadioButton button = new JRadioButton(buttonName);
      button.addActionListener(event -> demoPanel.setBorder(b));
      group.add(button);
      buttonPanel.add(button);
   }
}

测试程序6

1.在elipse IDE中调试运行教材498页程序12-6，结合运行结果理解程序；

2.掌握组合框组件的用法；

3.记录示例代码阅读理解中存在的问题与疑惑。

package comboBox;

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

/**
 * @version 1.35 2015-06-12
 * @author Cay Horstmann
 */
public class ComboBoxTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() -> {
         JFrame frame = new ComboBoxFrame();
         frame.setTitle("ComboBoxTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

package comboBox;

import java.awt.BorderLayout;
import java.awt.Font;

import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

/**
 * 具有样本文本标签和选择字体面的组合框的框架。
 */
public class ComboBoxFrame extends JFrame
{
   private JComboBox faceCombo;
   private JLabel label;
   private static final int DEFAULT_SIZE = 24;

   public ComboBoxFrame()
   {
      // 添加示例文本标签

      label = new JLabel("The quick brown fox jumps over the lazy dog.");
      label.setFont(new Font("Serif", Font.PLAIN, DEFAULT_SIZE));
      add(label, BorderLayout.CENTER);

      // 制作组合框并添加面部名称

      faceCombo = new JComboBox<>();
      faceCombo.addItem("Serif");
      faceCombo.addItem("SansSerif");
      faceCombo.addItem("Monospaced");
      faceCombo.addItem("Dialog");
      faceCombo.addItem("DialogInput");

      // 组合框侦听器将标签字体更改为选定的面部名称。

      faceCombo.addActionListener(event ->
         label.setFont(
            new Font(faceCombo.getItemAt(faceCombo.getSelectedIndex()), 
               Font.PLAIN, DEFAULT_SIZE)));

      // 将组合框添加到框架的南部边界的面板上

      JPanel comboPanel = new JPanel();
      comboPanel.add(faceCombo);
      add(comboPanel, BorderLayout.SOUTH);
      pack();
   }
}

测试程序7

1.在elipse IDE中调试运行教材501页程序12-7，结合运行结果理解程序；

2.掌握滑动条组件的用法；

3.记录示例代码阅读理解中存在的问题与疑惑。

package slider;

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

/**
 * @version 1.15 2015-06-12
 * @author Cay Horstmann
 */
public class SliderTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() -> {
         SliderFrame frame = new SliderFrame();
         frame.setTitle("SliderTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

package slider;

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

/**
 * 一个具有许多滑块和文本字段的滑块值的框架。
 */
public class SliderFrame extends JFrame
{
   private JPanel sliderPanel;
   private JTextField textField;
   private ChangeListener listener;

   public SliderFrame()
   {
      sliderPanel = new JPanel();
      sliderPanel.setLayout(new GridBagLayout());

      // 所有滑块的公用侦听器
      listener = event -> {
         // 当滑块值改变时更新文本字段
         JSlider source = (JSlider) event.getSource();
         textField.setText("" + source.getValue());
      };

      // 添加普通滑块

      JSlider slider = new JSlider();
      addSlider(slider, "Plain");

      // 添加有主和小蜱的滑块

      slider = new JSlider();
      slider.setPaintTicks(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(5);
      addSlider(slider, "Ticks");

      // 添加一个滑动到滴答的滑块
      slider = new JSlider();
      slider.setPaintTicks(true);
      slider.setSnapToTicks(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(5);
      addSlider(slider, "Snap to ticks");

      // 添加没有磁道的滑块

      slider = new JSlider();
      slider.setPaintTicks(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(5);
      slider.setPaintTrack(false);
      addSlider(slider, "No track");

      // 添加倒置滑块
      slider = new JSlider();
      slider.setPaintTicks(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(5);
      slider.setInverted(true);
      addSlider(slider, "Inverted");

      // 添加带有数字标签的滑块

      slider = new JSlider();
      slider.setPaintTicks(true);
      slider.setPaintLabels(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(5);
      addSlider(slider, "Labels");

      // 添加带有字母标签的滑块
      slider = new JSlider();
      slider.setPaintLabels(true);
      slider.setPaintTicks(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(5);

      Dictionary labelTable = new Hashtable<>();
      labelTable.put(0, new JLabel("A"));
      labelTable.put(20, new JLabel("B"));
      labelTable.put(40, new JLabel("C"));
      labelTable.put(60, new JLabel("D"));
      labelTable.put(80, new JLabel("E"));
      labelTable.put(100, new JLabel("F"));

      slider.setLabelTable(labelTable);
      addSlider(slider, "Custom labels");

      // 添加带有图标标签的滑块

      slider = new JSlider();
      slider.setPaintTicks(true);
      slider.setPaintLabels(true);
      slider.setSnapToTicks(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(20);

      labelTable = new Hashtable();

      // 添加卡片图像

      labelTable.put(0, new JLabel(new ImageIcon("nine.gif")));
      labelTable.put(20, new JLabel(new ImageIcon("ten.gif")));
      labelTable.put(40, new JLabel(new ImageIcon("jack.gif")));
      labelTable.put(60, new JLabel(new ImageIcon("queen.gif")));
      labelTable.put(80, new JLabel(new ImageIcon("king.gif")));
      labelTable.put(100, new JLabel(new ImageIcon("ace.gif")));

      slider.setLabelTable(labelTable);
      addSlider(slider, "Icon labels");

      // 添加显示滑块值的文本字段

      textField = new JTextField();
      add(sliderPanel, BorderLayout.CENTER);
      add(textField, BorderLayout.SOUTH);
      pack();
   }

   /**
    * 向滑块面板添加滑块并钩住听者
    * @param S滑块
    * @param 描述滑块描述
    */
   public void addSlider(JSlider s, String description)
   {
      s.addChangeListener(listener);
      JPanel panel = new JPanel();
      panel.add(s);
      panel.add(new JLabel(description));
      panel.setAlignmentX(Component.LEFT_ALIGNMENT);
      GridBagConstraints gbc = new GridBagConstraints();
      gbc.gridy = sliderPanel.getComponentCount();
      gbc.anchor = GridBagConstraints.WEST;
      sliderPanel.add(panel, gbc);
   }
}

测试程序8

1.在elipse IDE中调试运行教材512页程序12-8，结合运行结果理解程序；

2.掌握菜单的创建、菜单事件监听器、复选框和单选按钮菜单项、弹出菜单以及快捷键和加速器的用法。

3.记录示例代码阅读理解中存在的问题与疑惑。

package menu;

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

/**
 * @version 1.24 2012-06-12
 * @author Cay Horstmann
 */
public class MenuTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() -> {
         JFrame frame = new MenuFrame();
         frame.setTitle("MenuTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

package menu;

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

/**
 * 一个带有示例菜单栏的框架。
 */
public class MenuFrame extends JFrame
{
   private static final int DEFAULT_WIDTH = 300;
   private static final int DEFAULT_HEIGHT = 200;
   private Action saveAction;
   private Action saveAsAction;
   private JCheckBoxMenuItem readonlyItem;
   private JPopupMenu popup;

   /**
    * 将动作名称打印到Studio.OUT的示例动作。
    */
   class TestAction extends AbstractAction
   {
      public TestAction(String name)
      {
         super(name);
      }

      public void actionPerformed(ActionEvent event)
      {
         System.out.println(getValue(Action.NAME) + " selected.");
      }
   }

   public MenuFrame()
   {
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

      JMenu fileMenu = new JMenu("File");
      fileMenu.add(new TestAction("New"));

      // 演示加速器
      JMenuItem openItem = fileMenu.add(new TestAction("Open"));
      openItem.setAccelerator(KeyStroke.getKeyStroke("ctrl O"));

      fileMenu.addSeparator();

      saveAction = new TestAction("Save");
      JMenuItem saveItem = fileMenu.add(saveAction);
      saveItem.setAccelerator(KeyStroke.getKeyStroke("ctrl S"));

      saveAsAction = new TestAction("Save As");
      fileMenu.add(saveAsAction);
      fileMenu.addSeparator();

      fileMenu.add(new AbstractAction("Exit")
         {
            public void actionPerformed(ActionEvent event)
            {
               System.exit(0);
            }
         });

      // 演示复选框和单选按钮菜单

      readonlyItem = new JCheckBoxMenuItem("Read-only");
      readonlyItem.addActionListener(new ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               boolean saveOk = !readonlyItem.isSelected();
               saveAction.setEnabled(saveOk);
               saveAsAction.setEnabled(saveOk);
            }
         });

      ButtonGroup group = new ButtonGroup();

      JRadioButtonMenuItem insertItem = new JRadioButtonMenuItem("Insert");
      insertItem.setSelected(true);
      JRadioButtonMenuItem overtypeItem = new JRadioButtonMenuItem("Overtype");

      group.add(insertItem);
      group.add(overtypeItem);

      // 演示图标

      Action cutAction = new TestAction("Cut");
      cutAction.putValue(Action.SMALL_ICON, new ImageIcon("cut.gif"));
      Action copyAction = new TestAction("Copy");
      copyAction.putValue(Action.SMALL_ICON, new ImageIcon("copy.gif"));
      Action pasteAction = new TestAction("Paste");
      pasteAction.putValue(Action.SMALL_ICON, new ImageIcon("paste.gif"));

      JMenu editMenu = new JMenu("Edit");
      editMenu.add(cutAction);
      editMenu.add(copyAction);
      editMenu.add(pasteAction);

      // 演示嵌套菜单

      JMenu optionMenu = new JMenu("Options");

      optionMenu.add(readonlyItem);
      optionMenu.addSeparator();
      optionMenu.add(insertItem);
      optionMenu.add(overtypeItem);

      editMenu.addSeparator();
      editMenu.add(optionMenu);

      // 助记符演示

      JMenu helpMenu = new JMenu("Help");
      helpMenu.setMnemonic('H');

      JMenuItem indexItem = new JMenuItem("Index");
      indexItem.setMnemonic('I');
      helpMenu.add(indexItem);

      // 还可以将助记键添加到动作中。
      Action aboutAction = new TestAction("About");
      aboutAction.putValue(Action.MNEMONIC_KEY, new Integer('A'));
      helpMenu.add(aboutAction);
      
      // 将所有顶级菜单添加到菜单栏

      JMenuBar menuBar = new JMenuBar();
      setJMenuBar(menuBar);

      menuBar.add(fileMenu);
      menuBar.add(editMenu);
      menuBar.add(helpMenu);

      // 演示弹出窗口

      popup = new JPopupMenu();
      popup.add(cutAction);
      popup.add(copyAction);
      popup.add(pasteAction);

      JPanel panel = new JPanel();
      panel.setComponentPopupMenu(popup);
      add(panel);
   }
}

测试程序9

l 在elipse IDE中调试运行教材517页程序12-9，结合运行结果理解程序；

l 掌握工具栏和工具提示的用法；

l 记录示例代码阅读理解中存在的问题与疑惑

package toolBar;

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

/**
* A frame with a toolbar and menu for color changes.
*/
public class ToolBarFrame extends JFrame
{ //定义两个私有属性
private static final int DEFAULT_WIDTH = 300;
private static final int DEFAULT_HEIGHT = 200;
private JPanel panel;

public ToolBarFrame() //定义工具提示类
{
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

// add a panel for color change

panel = new JPanel();//创建新的JPanel
add(panel, BorderLayout.CENTER);

// set up actions
//建立动作

Action blueAction = new ColorAction("Blue", new ImageIcon("blue-ball.gif"), Color.BLUE);
Action yellowAction = new ColorAction("Yellow", new ImageIcon("yellow-ball.gif"),
Color.YELLOW);
Action redAction = new ColorAction("Red", new ImageIcon("red-ball.gif"), Color.RED);

Action exitAction = new AbstractAction("Exit", new ImageIcon("exit.gif"))
{
public void actionPerformed(ActionEvent event)
{
System.exit(0);
}
};
exitAction.putValue(Action.SHORT_DESCRIPTION, "Exit");

// populate toolbar

JToolBar bar = new JToolBar();
bar.add(blueAction);//用Action对象填充工具栏
bar.add(yellowAction);
bar.add(redAction);
bar.addSeparator();//用分隔符将按钮分组
bar.add(exitAction);
add(bar, BorderLayout.NORTH);

// populate menu

JMenu menu = new JMenu("Color");//显示颜色的菜单
menu.add(yellowAction);//在菜单添加颜色动作
menu.add(blueAction);
menu.add(redAction);
menu.add(exitAction);
JMenuBar menuBar = new JMenuBar();
menuBar.add(menu);
setJMenuBar(menuBar);
}

/**
* The color action sets the background of the frame to a given color.
*/
class ColorAction extends AbstractAction
{
public ColorAction(String name, Icon icon, Color c)
{
putValue(Action.NAME, name);//动作名称，显示在按钮和菜单
putValue(Action.SMALL_ICON, icon);//存储小图标的地方；显示在按钮、菜单项或工具栏中
putValue(Action.SHORT_DESCRIPTION, name + " background");
putValue("Color", c);
}

public void actionPerformed(ActionEvent event)
{
Color c = (Color) getValue("Color");
panel.setBackground(c);
}
}
}

测试程序10

l 在elipse IDE中调试运行教材524页程序12-10、12-11，结合运行结果理解程序，了解GridbagLayout的用法。

l 在elipse IDE中调试运行教材533页程序12-12，结合程序运行结果理解程序，了解GroupLayout的用法。

l 记录示例代码阅读理解中存在的问题与疑惑。

import java.awt.Font;
import java.awt.GridBagLayout;
import java.awt.event.ActionListener;

import javax.swing.BorderFactory;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextArea;

/**
* A frame that uses a grid bag layout to arrange font selection components.
*/
public class FontFrame extends JFrame
{
public static final int TEXT_ROWS = 10;
public static final int TEXT_COLUMNS = 20;

private JComboBox face;
private JComboBox size;
private JCheckBox bold;
private JCheckBox italic;
private JTextArea sample;

public FontFrame()
{
GridBagLayout layout = new GridBagLayout();
setLayout(layout);

ActionListener listener = event -> updateSample();

// construct components

JLabel faceLabel = new JLabel("Face: ");

face = new JComboBox<>(new String[] { "Serif", "SansSerif", "Monospaced",
"Dialog", "DialogInput" });

face.addActionListener(listener);

JLabel sizeLabel = new JLabel("Size: ");

size = new JComboBox<>(new Integer[] { 8, 10, 12, 15, 18, 24, 36, 48 });

size.addActionListener(listener);

bold = new JCheckBox("Bold");
bold.addActionListener(listener);

italic = new JCheckBox("Italic");
italic.addActionListener(listener);

sample = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);
sample.setText("The quick brown fox jumps over the lazy dog");
sample.setEditable(false);
sample.setLineWrap(true);
sample.setBorder(BorderFactory.createEtchedBorder());

// add components to grid, using GBC convenience class

add(faceLabel, new GBC(0, 0).setAnchor(GBC.EAST));
add(face, new GBC(1, 0).setFill(GBC.HORIZONTAL).setWeight(100, 0)
.setInsets(1));
add(sizeLabel, new GBC(0, 1).setAnchor(GBC.EAST));
add(size, new GBC(1, 1).setFill(GBC.HORIZONTAL).setWeight(100, 0)
.setInsets(1));
add(bold, new GBC(0, 2, 2, 1).setAnchor(GBC.CENTER).setWeight(100, 100));
add(italic, new GBC(0, 3, 2, 1).setAnchor(GBC.CENTER).setWeight(100, 100));
add(sample, new GBC(2, 0, 1, 4).setFill(GBC.BOTH).setWeight(100, 100));
pack();
updateSample();
}

public void updateSample()
{
String fontFace = (String) face.getSelectedItem();
int fontStyle = (bold.isSelected() ? Font.BOLD : 0)
+ (italic.isSelected() ? Font.ITALIC : 0);
int fontSize = size.getItemAt(size.getSelectedIndex());
Font font = new Font(fontFace, fontStyle, fontSize);
sample.setFont(font);
sample.repaint();
}
}

import java.awt.*;

/**
* This class simplifies the use of the GridBagConstraints class.
* @version 1.01 2004-05-06
* @author Cay Horstmann
*/
public class GBC extends GridBagConstraints
{
/**
* Constructs a GBC with a given gridx and gridy position and all other grid
* bag constraint values set to the default.
* @param gridx the gridx position
* @param gridy the gridy position
*/
public GBC(int gridx, int gridy)
{
this.gridx = gridx;
this.gridy = gridy;
}

/**
* Constructs a GBC with given gridx, gridy, gridwidth, gridheight and all
* other grid bag constraint values set to the default.
* @param gridx the gridx position
* @param gridy the gridy position
* @param gridwidth the cell span in x-direction
* @param gridheight the cell span in y-direction
*/
public GBC(int gridx, int gridy, int gridwidth, int gridheight)
{
this.gridx = gridx;
this.gridy = gridy;
this.gridwidth = gridwidth;
this.gridheight = gridheight;
}

/**
* Sets the anchor.
* @param anchor the anchor value
* @return this object for further modification
*/
public GBC setAnchor(int anchor)
{
this.anchor = anchor;
return this;
}

/**
* Sets the fill direction.
* @param fill the fill direction
* @return this object for further modification
*/
public GBC setFill(int fill)
{
this.fill = fill;
return this;
}

/**
* Sets the cell weights.
* @param weightx the cell weight in x-direction
* @param weighty the cell weight in y-direction
* @return this object for further modification
*/
public GBC setWeight(double weightx, double weighty)
{
this.weightx = weightx;
this.weighty = weighty;
return this;
}

/**
* Sets the insets of this cell.
* @param distance the spacing to use in all directions
* @return this object for further modification
*/
public GBC setInsets(int distance)
{
this.insets = new Insets(distance, distance, distance, distance);
return this;
}

/**
* Sets the insets of this cell.
* @param top the spacing to use on top
* @param left the spacing to use to the left
* @param bottom the spacing to use on the bottom
* @param right the spacing to use to the right
* @return this object for further modification
*/
public GBC setInsets(int top, int left, int bottom, int right)
{
this.insets = new Insets(top, left, bottom, right);
return this;
}

/**
* Sets the internal padding
* @param ipadx the internal padding in x-direction
* @param ipady the internal padding in y-direction
* @return this object for further modification
*/
public GBC setIpad(int ipadx, int ipady)
{
this.ipadx = ipadx;
this.ipady = ipady;
return this;
}
}

测试程序11

l 在elipse IDE中调试运行教材539页程序12-13、12-14，结合运行结果理解程序；

l 掌握定制布局管理器的用法。

l 记录示例代码阅读理解中存在的问题与疑惑。

package circleLayout;

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

/**
 * @version 1.33 2015-06-12
 * @author Cay Horstmann
 */
public class CircleLayoutTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() -> {
         JFrame frame = new CircleLayoutFrame();
         frame.setTitle("CircleLayoutTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

package circleLayout;

import javax.swing.*;

/**
 * A frame that shows buttons arranged along a circle.
 */
public class CircleLayoutFrame extends JFrame
{
   public CircleLayoutFrame()
   {
      setLayout(new CircleLayout());
      add(new JButton("Yellow"));
      add(new JButton("Blue"));
      add(new JButton("Red"));
      add(new JButton("Green"));
      add(new JButton("Orange"));
      add(new JButton("Fuchsia"));
      add(new JButton("Indigo"));
      pack();
   }
}

package circleLayout;

import java.awt.*;

/**
 * A layout manager that lays out components along a circle.
 */
public class CircleLayout implements LayoutManager
{
   private int minWidth = 0;
   private int minHeight = 0;
   private int preferredWidth = 0;
   private int preferredHeight = 0;
   private boolean sizesSet = false;
   private int maxComponentWidth = 0;
   private int maxComponentHeight = 0;

   public void addLayoutComponent(String name, Component comp)
   {
   }

   public void removeLayoutComponent(Component comp)
   {
   }

   public void setSizes(Container parent)
   {
      if (sizesSet) return;
      int n = parent.getComponentCount();

      preferredWidth = 0;
      preferredHeight = 0;
      minWidth = 0;
      minHeight = 0;
      maxComponentWidth = 0;
      maxComponentHeight = 0;

      // compute the maximum component widths and heights
      // and set the preferred size to the sum of the component sizes.
      for (int i = 0; i < n; i++)
      {
         Component c = parent.getComponent(i);
         if (c.isVisible())
         {
            Dimension d = c.getPreferredSize();
            maxComponentWidth = Math.max(maxComponentWidth, d.width);
            maxComponentHeight = Math.max(maxComponentHeight, d.height);
            preferredWidth += d.width;
            preferredHeight += d.height;
         }
      }
      minWidth = preferredWidth / 2;
      minHeight = preferredHeight / 2;
      sizesSet = true;
   }

   public Dimension preferredLayoutSize(Container parent)
   {
      setSizes(parent);
      Insets insets = parent.getInsets();
      int width = preferredWidth + insets.left + insets.right;
      int height = preferredHeight + insets.top + insets.bottom;
      return new Dimension(width, height);
   }

   public Dimension minimumLayoutSize(Container parent)
   {
      setSizes(parent);
      Insets insets = parent.getInsets();
      int width = minWidth + insets.left + insets.right;
      int height = minHeight + insets.top + insets.bottom;
      return new Dimension(width, height);
   }

   public void layoutContainer(Container parent)
   {
      setSizes(parent);

      // compute center of the circle

      Insets insets = parent.getInsets();
      int containerWidth = parent.getSize().width - insets.left - insets.right;
      int containerHeight = parent.getSize().height - insets.top - insets.bottom;

      int xcenter = insets.left + containerWidth / 2;
      int ycenter = insets.top + containerHeight / 2;

      // compute radius of the circle

      int xradius = (containerWidth - maxComponentWidth) / 2;
      int yradius = (containerHeight - maxComponentHeight) / 2;
      int radius = Math.min(xradius, yradius);

      // lay out components along the circle

      int n = parent.getComponentCount();
      for (int i = 0; i < n; i++)
      {
         Component c = parent.getComponent(i);
         if (c.isVisible())
         {
            double angle = 2 * Math.PI * i / n;

            // center point of component
            int x = xcenter + (int) (Math.cos(angle) * radius);
            int y = ycenter + (int) (Math.sin(angle) * radius);

            // move component so that its center is (x, y)
            // and its size is its preferred size
            Dimension d = c.getPreferredSize();
            c.setBounds(x - d.width / 2, y - d.height / 2, d.width, d.height);
         }
      }
   }
}

测试程序12

l 在elipse IDE中调试运行教材544页程序12-15、12-16，结合运行结果理解程序；

l 掌握选项对话框的用法。

l 记录示例代码阅读理解中存在的问题与疑惑。

package optionDialog;

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

/**
* A frame that contains settings for selecting various option dialogs.
*/
public class OptionDialogFrame extends JFrame//对话框
{ //定义属性
private ButtonPanel typePanel;
private ButtonPanel messagePanel;
private ButtonPanel messageTypePanel;
private ButtonPanel optionTypePanel;
private ButtonPanel optionsPanel;
private ButtonPanel inputPanel;
private String messageString = "Message";
private Icon messageIcon = new ImageIcon("blue-ball.gif");
private Object messageObject = new Date();
private Component messageComponent = new SampleComponent();

public OptionDialogFrame()
{
JPanel gridPanel = new JPanel();
gridPanel.setLayout(new GridLayout(2, 3));

typePanel = new ButtonPanel("Type", "Message", "Confirm", "Option", "Input");
messageTypePanel = new ButtonPanel("Message Type", "ERROR_MESSAGE", "INFORMATION_MESSAGE",
"WARNING_MESSAGE", "QUESTION_MESSAGE", "PLAIN_MESSAGE");
messagePanel = new ButtonPanel("Message", "String", "Icon", "Component", "Other", 
"Object[]");
optionTypePanel = new ButtonPanel("Confirm", "DEFAULT_OPTION", "YES_NO_OPTION",
"YES_NO_CANCEL_OPTION", "OK_CANCEL_OPTION");
optionsPanel = new ButtonPanel("Option", "String[]", "Icon[]", "Object[]");
inputPanel = new ButtonPanel("Input", "Text field", "Combo box");

gridPanel.add(typePanel);
gridPanel.add(messageTypePanel);
gridPanel.add(messagePanel);
gridPanel.add(optionTypePanel);
gridPanel.add(optionsPanel);
gridPanel.add(inputPanel);

// add a panel with a Show button

JPanel showPanel = new JPanel();
JButton showButton = new JButton("Show");
showButton.addActionListener(new ShowAction());
showPanel.add(showButton);

add(gridPanel, BorderLayout.CENTER);
add(showPanel, BorderLayout.SOUTH);
pack();
}

/**
* Gets the currently selected message.
* @return a string, icon, component, or object array, depending on the Message panel selection
*/
public Object getMessage()
{
String s = messagePanel.getSelection();
if (s.equals("String")) return messageString;
else if (s.equals("Icon")) return messageIcon;
else if (s.equals("Component")) return messageComponent;
else if (s.equals("Object[]")) return new Object[] { messageString, messageIcon,
messageComponent, messageObject };
else if (s.equals("Other")) return messageObject;
else return null;
}

/**
* Gets the currently selected options.
* @return an array of strings, icons, or objects, depending on the Option panel selection
*/
public Object[] getOptions()
{
String s = optionsPanel.getSelection();
if (s.equals("String[]")) return new String[] { "Yellow", "Blue", "Red" };
else if (s.equals("Icon[]")) return new Icon[] { new ImageIcon("yellow-ball.gif"),
new ImageIcon("blue-ball.gif"), new ImageIcon("red-ball.gif") };
else if (s.equals("Object[]")) return new Object[] { messageString, messageIcon,
messageComponent, messageObject };
else return null;
}

/**
* Gets the selected message or option type
* @param panel the Message Type or Confirm panel
* @return the selected XXX_MESSAGE or XXX_OPTION constant from the JOptionPane class
*/
public int getType(ButtonPanel panel)
{
String s = panel.getSelection();
try
{
return JOptionPane.class.getField(s).getInt(null);
}
catch (Exception e)
{
return -1;
}
}

/**
* The action listener for the Show button shows a Confirm, Input, Message, or Option dialog
* depending on the Type panel selection.
*/
private class ShowAction implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
if (typePanel.getSelection().equals("Confirm")) JOptionPane.showConfirmDialog(
OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel),
getType(messageTypePanel));
else if (typePanel.getSelection().equals("Input"))
{
if (inputPanel.getSelection().equals("Text field")) JOptionPane.showInputDialog(
OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel));
else JOptionPane.showInputDialog(OptionDialogFrame.this, getMessage(), "Title",
getType(messageTypePanel), null, new String[] { "Yellow", "Blue", "Red" },
"Blue");
}
else if (typePanel.getSelection().equals("Message")) JOptionPane.showMessageDialog(
OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel));
else if (typePanel.getSelection().equals("Option")) JOptionPane.showOptionDialog(
OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel),
getType(messageTypePanel), null, getOptions(), getOptions()[0]);
}
}
}

/**
* A component with a painted surface
*/

class SampleComponent extends JComponent
{
public void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D) g;
Rectangle2D rect = new Rectangle2D.Double(0, 0, getWidth() - 1, getHeight() - 1);
g2.setPaint(Color.YELLOW);
g2.fill(rect);
g2.setPaint(Color.BLUE);
g2.draw(rect);
}

public Dimension getPreferredSize()
{
return new Dimension(10, 10);
}
}

package optionDialog;

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

/**
* @version 1.34 2015-06-12
* @author Cay Horstmann
*/
public class OptionDialogTest
{
public static void main(String[] args)
{
EventQueue.invokeLater(() -> {
JFrame frame = new OptionDialogFrame();
frame.setTitle("OptionDialogTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
});
}

测试程序13

l 在elipse IDE中调试运行教材552页程序12-17、12-18，结合运行结果理解程序；

l 掌握对话框的创建方法；

l 记录示例代码阅读理解中存在的问题与疑惑。

package dialog;

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

/**
 * @version 1.34 2012-06-12
 * @author Cay Horstmann
 */
public class DialogTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() -> {
         JFrame frame = new DialogFrame();
         frame.setTitle("DialogTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

package dialog;

import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;

/**
 * A frame with a menu whose File->About action shows a dialog.
 */
public class DialogFrame extends JFrame
{
   private static final int DEFAULT_WIDTH = 300;
   private static final int DEFAULT_HEIGHT = 200;
   private AboutDialog dialog;

   public DialogFrame()
   {
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

      // Construct a File menu.

      JMenuBar menuBar = new JMenuBar();
      setJMenuBar(menuBar);
      JMenu fileMenu = new JMenu("File");
      menuBar.add(fileMenu);

      // Add About and Exit menu items.

      // The About item shows the About dialog.

      JMenuItem aboutItem = new JMenuItem("About");
      aboutItem.addActionListener(event -> {
         if (dialog == null) // first time
            dialog = new AboutDialog(DialogFrame.this);
         dialog.setVisible(true); // pop up dialog
      });
      fileMenu.add(aboutItem);

      // The Exit item exits the program.

      JMenuItem exitItem = new JMenuItem("Exit");
      exitItem.addActionListener(event -> System.exit(0));
      fileMenu.add(exitItem);
   }
}

package dialog;

import java.awt.BorderLayout;

import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

/**
 * A sample modal dialog that displays a message and waits for the user to click the OK button.
 */
public class AboutDialog extends JDialog
{
   public AboutDialog(JFrame owner)
   {
      super(owner, "About DialogTest", true);

      // add HTML label to center

      add(
            new JLabel(
                  "
Core Java
By Cay Horstmann"),
            BorderLayout.CENTER);

      // OK button closes the dialog

      JButton ok = new JButton("OK");
      ok.addActionListener(event -> setVisible(false));

      // add OK button to southern border

      JPanel panel = new JPanel();
      panel.add(ok);
      add(panel, BorderLayout.SOUTH);

      pack();
   }
}

测试程序14

1.在elipse IDE中调试运行教材556页程序12-19、12-20，结合运行结果理解程序；

2.掌握对话框的数据交换用法;

3.记录示例代码阅读理解中存在的问题与疑惑。

package dataExchange;

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

/**
 * @version 1.34 2015-06-12
 * @author Cay Horstmann
 */
public class DataExchangeTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() -> {
         JFrame frame = new DataExchangeFrame();
         frame.setTitle("DataExchangeTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

package dataExchange;

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

/**
 * A frame with a menu whose File->Connect action shows a password dialog.
 */
public class DataExchangeFrame extends JFrame
{
   public static final int TEXT_ROWS = 20;
   public static final int TEXT_COLUMNS = 40;
   private PasswordChooser dialog = null;
   private JTextArea textArea;

   public DataExchangeFrame()
   {
      // construct a File menu

      JMenuBar mbar = new JMenuBar();
      setJMenuBar(mbar);
      JMenu fileMenu = new JMenu("File");
      mbar.add(fileMenu);

      // add Connect and Exit menu items

      JMenuItem connectItem = new JMenuItem("Connect");
      connectItem.addActionListener(new ConnectAction());
      fileMenu.add(connectItem);

      // The Exit item exits the program

      JMenuItem exitItem = new JMenuItem("Exit");
      exitItem.addActionListener(event -> System.exit(0));
      fileMenu.add(exitItem);

      textArea = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);
      add(new JScrollPane(textArea), BorderLayout.CENTER);
      pack();
   }

   /**
    * The Connect action pops up the password dialog.
    */
   private class ConnectAction implements ActionListener
   {
      public void actionPerformed(ActionEvent event)
      {
         // if first time, construct dialog

         if (dialog == null) dialog = new PasswordChooser();

         // set default values
         dialog.setUser(new User("yourname", null));

         // pop up dialog
         if (dialog.showDialog(DataExchangeFrame.this, "Connect"))
         {
            // if accepted, retrieve user input
            User u = dialog.getUser();
            textArea.append("user name = " + u.getName() + ", password = "
                  + (new String(u.getPassword())) + "\n");
         }
      }
   }
}

package dataExchange;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Frame;
import java.awt.GridLayout;

import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;

/**
 * A password chooser that is shown inside a dialog
 */
public class PasswordChooser extends JPanel
{
   private JTextField username;
   private JPasswordField password;
   private JButton okButton;
   private boolean ok;
   private JDialog dialog;

   public PasswordChooser()
   {
      setLayout(new BorderLayout());

      // construct a panel with user name and password fields

      JPanel panel = new JPanel();
      panel.setLayout(new GridLayout(2, 2));
      panel.add(new JLabel("User name:"));
      panel.add(username = new JTextField(""));
      panel.add(new JLabel("Password:"));
      panel.add(password = new JPasswordField(""));
      add(panel, BorderLayout.CENTER);

      // create Ok and Cancel buttons that terminate the dialog

      okButton = new JButton("Ok");
      okButton.addActionListener(event -> {
         ok = true;
         dialog.setVisible(false);
      });

      JButton cancelButton = new JButton("Cancel");
      cancelButton.addActionListener(event -> dialog.setVisible(false));

      // add buttons to southern border

      JPanel buttonPanel = new JPanel();
      buttonPanel.add(okButton);
      buttonPanel.add(cancelButton);
      add(buttonPanel, BorderLayout.SOUTH);
   }

   /**
    * Sets the dialog defaults.
    * @param u the default user information
    */
   public void setUser(User u)
   {
      username.setText(u.getName());
   }

   /**
    * Gets the dialog entries.
    * @return a User object whose state represents the dialog entries
    */
   public User getUser()
   {
      return new User(username.getText(), password.getPassword());
   }

   /**
    * Show the chooser panel in a dialog
    * @param parent a component in the owner frame or null
    * @param title the dialog window title
    */
   public boolean showDialog(Component parent, String title)
   {
      ok = false;

      // locate the owner frame

      Frame owner = null;
      if (parent instanceof Frame)
         owner = (Frame) parent;
      else
         owner = (Frame) SwingUtilities.getAncestorOfClass(Frame.class, parent);

      // if first time, or if owner has changed, make new dialog

      if (dialog == null || dialog.getOwner() != owner)
      {
         dialog = new JDialog(owner, true);
         dialog.add(this);
         dialog.getRootPane().setDefaultButton(okButton);
         dialog.pack();
      }

      // set title and show dialog

      dialog.setTitle(title);
      dialog.setVisible(true);
      return ok;
   }
}

package dataExchange;

/**
 * A user has a name and password. For security reasons, the password is stored as a char[], not a
 * String.
 */
public class User
{
   private String name;
   private char[] password;

   public User(String aName, char[] aPassword)
   {
      name = aName;
      password = aPassword;
   }

   public String getName()
   {
      return name;
   }

   public char[] getPassword()
   {
      return password;
   }

   public void setName(String aName)
   {
      name = aName;
   }

   public void setPassword(char[] aPassword)
   {
      password = aPassword;
   }
}

测试程序15

l 在elipse IDE中调试运行教材564页程序12-21、12-22、12-23，结合程序运行结果理解程序；

l 掌握文件对话框的用法;

l 记录示例代码阅读理解中存在的问题与疑惑。

package dataExchange;

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

/**
* A frame with a menu whose File->Connect action shows a password dialog.
*/
public class DataExchangeFrame extends JFrame
{
public static final int TEXT_ROWS = 20;
public static final int TEXT_COLUMNS = 40;
private PasswordChooser dialog = null;
private JTextArea textArea;

public DataExchangeFrame()
{
// construct a File menu

JMenuBar mbar = new JMenuBar();
setJMenuBar(mbar);
JMenu fileMenu = new JMenu("File");
mbar.add(fileMenu);

// add Connect and Exit menu items

JMenuItem connectItem = new JMenuItem("Connect");
connectItem.addActionListener(new ConnectAction());
fileMenu.add(connectItem);

// The Exit item exits the program

JMenuItem exitItem = new JMenuItem("Exit");
exitItem.addActionListener(event -> System.exit(0));
fileMenu.add(exitItem);

textArea = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);
add(new JScrollPane(textArea), BorderLayout.CENTER);
pack();
}

/**
* The Connect action pops up the password dialog.
*/
private class ConnectAction implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
// if first time, construct dialog

if (dialog == null) dialog = new PasswordChooser();

// set default values
dialog.setUser(new User("yourname", null));

// pop up dialog
if (dialog.showDialog(DataExchangeFrame.this, "Connect"))
{
// if accepted, retrieve user input
User u = dialog.getUser();
textArea.append("user name = " + u.getName() + ", password = "
+ (new String(u.getPassword())) + "\n");
}
}
}
}

package dataExchange;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Frame;
import java.awt.GridLayout;

import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;

/**
* A password chooser that is shown inside a dialog
*/
public class PasswordChooser extends JPanel
{
private JTextField username;
private JPasswordField password;
private JButton okButton;
private boolean ok;
private JDialog dialog;

public PasswordChooser()
{
setLayout(new BorderLayout());

// construct a panel with user name and password fields

JPanel panel = new JPanel();
panel.setLayout(new GridLayout(2, 2));
panel.add(new JLabel("User name:"));
panel.add(username = new JTextField(""));
panel.add(new JLabel("Password:"));
panel.add(password = new JPasswordField(""));
add(panel, BorderLayout.CENTER);

// create Ok and Cancel buttons that terminate the dialog

okButton = new JButton("Ok");
okButton.addActionListener(event -> {
ok = true;
dialog.setVisible(false);
});

JButton cancelButton = new JButton("Cancel");
cancelButton.addActionListener(event -> dialog.setVisible(false));

// add buttons to southern border

JPanel buttonPanel = new JPanel();
buttonPanel.add(okButton);
buttonPanel.add(cancelButton);
add(buttonPanel, BorderLayout.SOUTH);
}

/**
* Sets the dialog defaults.
* @param u the default user information
*/
public void setUser(User u)
{
username.setText(u.getName());
}

/**
* Gets the dialog entries.
* @return a User object whose state represents the dialog entries
*/
public User getUser()
{
return new User(username.getText(), password.getPassword());
}

/**
* Show the chooser panel in a dialog
* @param parent a component in the owner frame or null
* @param title the dialog window title
*/
public boolean showDialog(Component parent, String title)
{
ok = false;

// locate the owner frame

Frame owner = null;
if (parent instanceof Frame)
owner = (Frame) parent;
else
owner = (Frame) SwingUtilities.getAncestorOfClass(Frame.class, parent);

// if first time, or if owner has changed, make new dialog

if (dialog == null || dialog.getOwner() != owner)
{
dialog = new JDialog(owner, true);
dialog.add(this);
dialog.getRootPane().setDefaultButton(okButton);
dialog.pack();
}

// set title and show dialog

dialog.setTitle(title);
dialog.setVisible(true);
return ok;
}
}

package dataExchange;

/**
* A user has a name and password. For security reasons, the password is stored as a char[], not a
* String.
*/
public class User
{
private String name;
private char[] password;

public User(String aName, char[] aPassword)
{
name = aName;
password = aPassword;
}

public String getName()
{
return name;
}

public char[] getPassword()
{
return password;
}

public void setName(String aName)
{
name = aName;
}

public void setPassword(char[] aPassword)
{
password = aPassword;
}
}

测试程序16

l 在elipse IDE中调试运行教材570页程序12-24，结合运行结果理解程序；

l 了解颜色选择器的用法。

记录示例代码阅读理解中存在的问题与疑惑。

package colorChooser;

import java.awt.Color;
import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JDialog;
import javax.swing.JPanel;

/**
* A panel with buttons to pop up three types of color choosers
*/
public class ColorChooserPanel extends JPanel
{
public ColorChooserPanel()//狗仔一个初始颜色的颜色选择器
{
JButton modalButton = new JButton("Modal");
modalButton.addActionListener(new ModalListener());
add(modalButton);

JButton modelessButton = new JButton("Modeless");
modelessButton.addActionListener(new ModelessListener());
add(modelessButton);

JButton immediateButton = new JButton("Immediate");
immediateButton.addActionListener(new ImmediateListener());
add(immediateButton);
}

/**
* This listener pops up a modal color chooser
*/
private class ModalListener implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
Color defaultColor = getBackground();
Color selected = JColorChooser.showDialog(ColorChooserPanel.this, "Set background",
defaultColor);
if (selected != null) setBackground(selected);
}
}

/**
* This listener pops up a modeless color chooser. The panel color is changed when the user
* clicks the OK button.
*/
private class ModelessListener implements ActionListener
{
private JDialog dialog;
private JColorChooser chooser;

public ModelessListener()
{
chooser = new JColorChooser();
dialog = JColorChooser.createDialog(ColorChooserPanel.this, "Background Color",
false /* not modal */, chooser, 
event -> setBackground(chooser.getColor()), 
null /* no Cancel button listener */);
}

public void actionPerformed(ActionEvent event)
{
chooser.setColor(getBackground());
dialog.setVisible(true);
}
}

/**
* This listener pops up a modeless color chooser. The panel color is changed immediately when
* the user picks a new color.
*/
private class ImmediateListener implements ActionListener
{
private JDialog dialog;
private JColorChooser chooser;

public ImmediateListener()
{
chooser = new JColorChooser();
chooser.getSelectionModel().addChangeListener(
event -> setBackground(chooser.getColor()));

dialog = new JDialog((Frame) null, false /* not modal */);
dialog.add(chooser);
dialog.pack();
}

public void actionPerformed(ActionEvent event)
{
chooser.setColor(getBackground());
dialog.setVisible(true);
}
}
}

package colorChooser;

import javax.swing.*;

/**
* A frame with a color chooser panel
*/
public class ColorChooserFrame extends JFrame
{//设置两个私有属性
private static final int DEFAULT_WIDTH = 300;
private static final int DEFAULT_HEIGHT = 200;

public ColorChooserFrame()//颜色选择器
{ 
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

// add color chooser panel to frame

ColorChooserPanel panel = new ColorChooserPanel();
add(panel);
}
}

package colorChooser;

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

/**
* @version 1.04 2015-06-12
* @author Cay Horstmann
*/
public class ColorChooserTest
{
public static void main(String[] args)
{
EventQueue.invokeLater(() -> {
JFrame frame = new ColorChooserFrame();//生成ColorChooserFrame类
frame.setTitle("ColorChooserTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//关闭界面操作
frame.setVisible(true);
});
}
}

实验2：组内讨论反思本组负责程序，理解程序总体结构，梳理程序GUI设计中应用的相关组件，整理相关组件的API,对程序中组件应用的相关代码添加注释。

示例14、所添加注释：

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

/**
* @version 1.34 2015-06-12
* @author Cay Horstmann
*/
public class OptionDialogTest
{
public static void main(String[] args)
{
EventQueue.invokeLater(() -> {
JFrame frame = new OptionDialogFrame();
frame.setTitle("OptionDialogTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
});
}
}

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

/**
* 包含用于选择各种选项对话框的设置的框架。
*/
public class OptionDialogFrame extends JFrame
{
private ButtonPanel typePanel;
private ButtonPanel messagePanel;
private ButtonPanel messageTypePanel;
private ButtonPanel optionTypePanel;
private ButtonPanel optionsPanel;
private ButtonPanel inputPanel;
private String messageString = "Message";
private Icon messageIcon = new ImageIcon("blue-ball.gif");
private Object messageObject = new Date();
private Component messageComponent = new SampleComponent();

public OptionDialogFrame()
{
JPanel gridPanel = new JPanel();
gridPanel.setLayout(new GridLayout(2, 3));

typePanel = new ButtonPanel("Type", "Message", "Confirm", "Option", "Input");
messageTypePanel = new ButtonPanel("Message Type", "ERROR_MESSAGE", "INFORMATION_MESSAGE",
"WARNING_MESSAGE", "QUESTION_MESSAGE", "PLAIN_MESSAGE");
messagePanel = new ButtonPanel("Message", "String", "Icon", "Component", "Other", 
"Object[]");
optionTypePanel = new ButtonPanel("Confirm", "DEFAULT_OPTION", "YES_NO_OPTION",
"YES_NO_CANCEL_OPTION", "OK_CANCEL_OPTION");
optionsPanel = new ButtonPanel("Option", "String[]", "Icon[]", "Object[]");
inputPanel = new ButtonPanel("Input", "Text field", "Combo box");

gridPanel.add(typePanel);
gridPanel.add(messageTypePanel);
gridPanel.add(messagePanel);
gridPanel.add(optionTypePanel);
gridPanel.add(optionsPanel);
gridPanel.add(inputPanel);

// add a panel with a Show button

JPanel showPanel = new JPanel();
JButton showButton = new JButton("Show");
showButton.addActionListener(new ShowAction());
showPanel.add(showButton);

add(gridPanel, BorderLayout.CENTER);
add(showPanel, BorderLayout.SOUTH);
pack();
}

/**
* Gets the currently selected message.
* @return a string, icon, component, or object array, depending on the Message panel selection
*/
public Object getMessage()
{
String s = messagePanel.getSelection();
if (s.equals("String")) return messageString;
else if (s.equals("Icon")) return messageIcon;
else if (s.equals("Component")) return messageComponent;
else if (s.equals("Object[]")) return new Object[] { messageString, messageIcon,
messageComponent, messageObject };
else if (s.equals("Other")) return messageObject;
else return null;
}

/**
* Gets the currently selected options.
* @return an array of strings, icons, or objects, depending on the Option panel selection
*/
public Object[] getOptions()
{
String s = optionsPanel.getSelection();
if (s.equals("String[]")) return new String[] { "Yellow", "Blue", "Red" };
else if (s.equals("Icon[]")) return new Icon[] { new ImageIcon("yellow-ball.gif"),
new ImageIcon("blue-ball.gif"), new ImageIcon("red-ball.gif") };
else if (s.equals("Object[]")) return new Object[] { messageString, messageIcon,
messageComponent, messageObject };
else return null;
}

/**
* 获取所选消息或选项类型
* @param面板消息类型或确认面板
* @return JOptionPane类中选定的XXX_MESSAGE或XXX_OPTION常量
*/
public int getType(ButtonPanel panel)
{
String s = panel.getSelection();
try
{
return JOptionPane.class.getField(s).getInt(null);
}
catch (Exception e)
{
return -1;
}
}

/**
* “显示”按钮的动作侦听器显示“确认”，“输入”，“消息”或“选项”对话框
*取决于“类型”面板选择。
*/
private class ShowAction implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
if (typePanel.getSelection().equals("Confirm")) JOptionPane.showConfirmDialog(
OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel),
getType(messageTypePanel));
else if (typePanel.getSelection().equals("Input"))
{
if (inputPanel.getSelection().equals("Text field")) JOptionPane.showInputDialog(
OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel));
else JOptionPane.showInputDialog(OptionDialogFrame.this, getMessage(), "Title",
getType(messageTypePanel), null, new String[] { "Yellow", "Blue", "Red" },
"Blue");
}
else if (typePanel.getSelection().equals("Message")) JOptionPane.showMessageDialog(
OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel));
else if (typePanel.getSelection().equals("Option")) JOptionPane.showOptionDialog(
OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel),
getType(messageTypePanel), null, getOptions(), getOptions()[0]);
}
}
}

/**
* 具有涂漆表面的组件
*/

class SampleComponent extends JComponent
{
public void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D) g;
Rectangle2D rect = new Rectangle2D.Double(0, 0, getWidth() - 1, getHeight() - 1);
g2.setPaint(Color.YELLOW);
g2.fill(rect);
g2.setPaint(Color.BLUE);
g2.draw(rect);
}

public Dimension getPreferredSize()
{
return new Dimension(10, 10);
}
}

import javax.swing.*;

 

/**

 * 带标题边框内的单选按钮的面板.

 */

public class ButtonPanel extends JPanel

{

   private ButtonGroup group;

 

   /**

    * 构造一个按钮面板.

    * @param标题边框中显示的标题

    * @param选项一组单选按钮标签

    */

   public ButtonPanel(String title, String... options)

   {

      setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(), title));

      setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));

      group = new ButtonGroup();

 

      // make one radio button for each option

      for (String option : options)

      {

         JRadioButton b = new JRadioButton(option);

         b.setActionCommand(option);

         add(b);

         group.add(b);

         b.setSelected(option == options[0]);

      }

   }

 

   /**

    * 获取当前选定的选项。

    * @return当前所选单选按钮的标签。

    */

   public String getSelection()

   {

      return group.getSelection().getActionCommand();

   }

}

GUI相关组件： 

GUI窗口

　　Jframe是窗体组件。创建该组件即创建了一个窗口。窗口是一个容器组件，所有内容均可以放入其中。

　　创建窗体对象：

　　JFrame frame = newJFrame(“标题”);

　　// 在这里需要简单设置属性:

　　frame.setSize(int 宽,int 高); //设置窗体尺寸

　　frame.setLocation(int x轴，int y轴); //设置窗体位置

　　frame. setVisible(true); //设置窗体可见

　　this.setResizable(false); //设置窗体大小固定

　　this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// 关闭窗口默认操作

　　向窗体中添加其他组件：

　　frame.add(其他组件);

GUI布局

　　布局是指界面存放组件位置的方式。

　　如果组件凌乱地存放在容器当中不好看，通常可以采用对应布局方式，来规范组件的位置,Java也提供了常见的布局对象。

　　LayoutManager： 布局接口，各种布局类均为其子类

　　frame.setLayout(布局对象) //设置窗口布局

　　null：不使用布局，此时可以容器内的组件可以调用方法，通过坐标以及尺寸进行组件定位：

　　组件定位方法为void setBounds(int x轴，int y轴，int 宽度，int 高度)

　　BorderLayout：边界布局，将界面分为东西南北中5个方位，frame的默认布局

　　GUI面板

　　JPanel面板与JFrame窗体类似，属于容器组件，可以存放其他组件内容。通常用来划分区域，完成一个完整的功能。

　　通常的方式是： JFrame存放JPanel，JPanel存放其他组件。

　　GUI按钮

　　在容器内最终完成数据展示与交互的均为功能组件。组件众多，其他组件的使用方法均类似，这里不一一介绍。欢迎界面中使用到了Button组件。

　　Button btn = new Button();

　　通用步骤：

　　1、创建功能组件对象;

　　2、给功能组件绑定监听器;

　　3、将功能组件添加到容器组件中;

　　 GUI监听器

　　页面中的各种组件均包含一些Java预设的用户操作(如鼠标点击，键盘按键等)，如何在用户完成对应操作时，执行对应的代码，是事件监听机制完成的。

　　将发生预设事件的组件绑定监听器，监听器某个组件是否发生了用户操作，当用户进行对应的操作后，执行对应代码。

　　我们最常见的操作是鼠标点击按钮，是按钮的动作。这里介绍按钮的事件监听。

　　事件监听步骤：

　　① 被监听的组件调用方法与监听器关联

　　按钮组件关联监听器方法：addActionListener(监听器对象)

　　按钮动作监听器接口：ActionListener

　　② 在监听器中定义用户操作对应的执行代码

实验总结：

　　本次章节内容学习了许多图形用户界面组件，模型-视图-控制器设计模式、菜单栏的管理、布局管理的概述、文本输入、对话框、选择组件、gui程序排错等等。大致了解之后，还需要课下多加练习来熟悉这些组件。