实验十四 Swing图形界面组件
理论部分：
不使用布局管理器
有时候可能不想使用任何布局管理器，而只 是想把组件放在一个固定的位置上。下面是将一 个组件定位到某个绝对定位的步骤：
1）将布局管理器设置为null。
2）将组件添加到容器中。
3）指定想要放置的位置和大小。 frame.setLayout(null); Jbutton ok = new Jbutton("ok"); frame.add(ok); ok.setBounds(10,10,30,15);
定制布局管理器
程序员可通过自己设计LayoutManager类来实现特殊的布局方式。定制布局管理器需要实现LayoutManager接口，并覆盖以下方法。 void addLayoutComponent(String s,Component c);
将组件添加到布局中
参数：s：组件位置的标识符
c：被添加的组件
void removeLayoutComponent(Component c);
从本布局中删除一个组件
Dimension preferredLayoutSize(Container parent);
返回本布局下的容器的首选尺寸
Dimension minimumLayoutSize(Container panent);
返回本布局下的容器的最小尺寸
void layoutContainer(container parent);
摆放容器内的组件
在添加或删除一个组件时会调用前面两个方法。如果不需要保存组件的任何附加信息那么可以让着两个方法什么都不做。接下来的两个方法计算组件的最小布局和首选布局所需要的空间。两者通常相等，第五个方法真正的实施操作，它调用所有组件的Setbounds方法。
遍历顺序
当把很多组件添加到窗口中时，需要考虑遍历顺序问题。窗口被初次使用时，遍历序列的第一个组件会有键盘焦点。没词用户按下TAB键，下一个组件就会获得焦点，
遍历顺序很直观，顺序是从左至右，从上至下，组件按照以下顺序进行遍历：
（1）外观组合框：
（2）示例文本区：
（3）尺寸组合框：
（4）加粗复选框：
（5）斜体复选框；
如果容器还包括其他的容器,情况会更加复杂。当然点给予另外一个容器时，那个容器左上角的组件就会自动的活动焦点，然后再遍历那个额容器中的所有组件。最后，将焦点移交给紧跟着那个容器的组件。利用这一点可以将相关元素组织在一起并放置在一个容器中。例如放置在一个面板中。
实验时间 20178-11-29
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；
1 package calculator; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class Calculator 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 CalculatorFrame frame = new CalculatorFrame(); 16 frame.setTitle("Calculator"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
1 package calculator; 2 3 import javax.swing.*; 4 5 /** 6 * A frame with a calculator panel. 7 */ 8 public class CalculatorFrame extends JFrame 9 { 10 public CalculatorFrame() 11 { 12 add(new CalculatorPanel()); 13 pack(); 14 } 15 }
1 package calculator; 2 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 /** 8 * A panel with calculator buttons and a result display. 9 */ 10 public class CalculatorPanel extends JPanel 11 { 12 private JButton display; 13 private JPanel panel; 14 private double result; 15 private String lastCommand; 16 private boolean start; 17 18 public CalculatorPanel() 19 { 20 setLayout(new BorderLayout()); 21 22 result = 0; 23 lastCommand = "="; 24 start = true; 25 26 // add the display 27 28 display = new JButton("0"); 29 display.setEnabled(false); 30 add(display, BorderLayout.NORTH); 31 32 ActionListener insert = new InsertAction(); 33 ActionListener command = new CommandAction(); 34 35 // add the buttons in a 4 x 4 grid 36 37 panel = new JPanel(); 38 panel.setLayout(new GridLayout(4, 4)); 39 40 addButton("7", insert); 41 addButton("8", insert); 42 addButton("9", insert); 43 addButton("/", command); 44 45 addButton("4", insert); 46 addButton("5", insert); 47 addButton("6", insert); 48 addButton("*", command); 49 50 addButton("1", insert); 51 addButton("2", insert); 52 addButton("3", insert); 53 addButton("-", command); 54 55 addButton("0", insert); 56 addButton(".", insert); 57 addButton("=", command); 58 addButton("+", command); 59 60 add(panel, BorderLayout.CENTER); 61 } 62 63 /** 64 * Adds a button to the center panel. 65 * @param label the button label 66 * @param listener the button listener 67 */ 68 private void addButton(String label, ActionListener listener) 69 { 70 JButton button = new JButton(label); 71 button.addActionListener(listener); 72 panel.add(button); 73 } 74 75 /** 76 * This action inserts the button action string to the end of the display text. 77 */ 78 private class InsertAction implements ActionListener 79 { 80 public void actionPerformed(ActionEvent event) 81 { 82 String input = event.getActionCommand(); 83 if (start) 84 { 85 display.setText(""); 86 start = false; 87 } 88 display.setText(display.getText() + input); 89 } 90 } 91 92 /** 93 * This action executes the command that the button action string denotes. 94 */ 95 private class CommandAction implements ActionListener 96 { 97 public void actionPerformed(ActionEvent event) 98 { 99 String command = event.getActionCommand(); 100 101 if (start) 102 { 103 if (command.equals("-")) 104 { 105 display.setText(command); 106 start = false; 107 } 108 else lastCommand = command; 109 } 110 else 111 { 112 calculate(Double.parseDouble(display.getText())); 113 lastCommand = command; 114 start = true; 115 } 116 } 117 } 118 119 /** 120 * Carries out the pending calculation. 121 * @param x the value to be accumulated with the prior result. 122 */ 123 public void calculate(double x) 124 { 125 if (lastCommand.equals("+")) result += x; 126 else if (lastCommand.equals("-")) result -= x; 127 else if (lastCommand.equals("*")) result *= x; 128 else if (lastCommand.equals("/")) result /= x; 129 else if (lastCommand.equals("=")) result = x; 130 display.setText("" + result); 131 } 132 }
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。
1 package text; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.41 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class TextComponentTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new TextComponentFrame(); 16 frame.setTitle("TextComponentTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
1 package text; 2 3 import java.awt.BorderLayout; 4 import java.awt.GridLayout; 5 6 import javax.swing.JButton; 7 import javax.swing.JFrame; 8 import javax.swing.JLabel; 9 import javax.swing.JPanel; 10 import javax.swing.JPasswordField; 11 import javax.swing.JScrollPane; 12 import javax.swing.JTextArea; 13 import javax.swing.JTextField; 14 import javax.swing.SwingConstants; 15 16 /** 17 * A frame with sample text components. 18 */ 19 public class TextComponentFrame extends JFrame 20 { 21 public static final int TEXTAREA_ROWS = 8; 22 public static final int TEXTAREA_COLUMNS = 20; 23 24 public TextComponentFrame() 25 { 26 JTextField textField = new JTextField(); 27 JPasswordField passwordField = new JPasswordField(); 28 29 JPanel northPanel = new JPanel(); 30 northPanel.setLayout(new GridLayout(2, 2)); 31 northPanel.add(new JLabel("User name: ", SwingConstants.RIGHT)); 32 northPanel.add(textField); 33 northPanel.add(new JLabel("Password: ", SwingConstants.RIGHT)); 34 northPanel.add(passwordField); 35 36 add(northPanel, BorderLayout.NORTH); 37 38 JTextArea textArea = new JTextArea(TEXTAREA_ROWS, TEXTAREA_COLUMNS); 39 JScrollPane scrollPane = new JScrollPane(textArea); 40 41 add(scrollPane, BorderLayout.CENTER); 42 43 // add button to append text into the text area 44 45 JPanel southPanel = new JPanel(); 46 47 JButton insertButton = new JButton("Insert"); 48 southPanel.add(insertButton); 49 insertButton.addActionListener(event -> 50 textArea.append("User name: " + textField.getText() + " Password: " 51 + new String(passwordField.getPassword()) + "\n")); 52 53 add(southPanel, BorderLayout.SOUTH); 54 pack(); 55 } 56 }
测试程序3
l 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；
l 掌握复选框组件的用法；
l 记录示例代码阅读理解中存在的问题与疑惑。
1 package checkBox; 2 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 /** 8 * A frame with a sample text label and check boxes for selecting font 9 * attributes. 10 */ 11 public class CheckBoxFrame extends JFrame 12 { 13 private JLabel label; 14 private JCheckBox bold; 15 private JCheckBox italic; 16 private static final int FONTSIZE = 24; 17 18 public CheckBoxFrame() 19 { 20 // add the sample text label 21 22 label = new JLabel("The quick brown fox jumps over the lazy dog."); 23 label.setFont(new Font("Serif", Font.BOLD, FONTSIZE)); 24 add(label, BorderLayout.CENTER); 25 26 // this listener sets the font attribute of 27 // the label to the check box state 28 29 ActionListener listener = event -> { 30 int mode = 0; 31 if (bold.isSelected()) mode += Font.BOLD; 32 if (italic.isSelected()) mode += Font.ITALIC; 33 label.setFont(new Font("Serif", mode, FONTSIZE)); 34 }; 35 36 // add the check boxes 37 38 JPanel buttonPanel = new JPanel(); 39 40 bold = new JCheckBox("Bold"); 41 bold.addActionListener(listener); 42 bold.setSelected(true); 43 buttonPanel.add(bold); 44 45 italic = new JCheckBox("Italic"); 46 italic.addActionListener(listener); 47 buttonPanel.add(italic); 48 49 add(buttonPanel, BorderLayout.SOUTH); 50 pack(); 51 } 52 }
1 package checkBox; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class CheckBoxTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new CheckBoxFrame(); 16 frame.setTitle("CheckBoxTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
测试程序4
l 在elipse IDE中调试运行教材491页程序12-4，运行结果理解程序；
l 掌握单选按钮组件的用法；
l 记录示例代码阅读理解中存在的问题与疑惑。
1 package radioButton; 2 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 /** 8 * A frame with a sample text label and radio buttons for selecting font sizes. 9 */ 10 public class RadioButtonFrame extends JFrame 11 { 12 private JPanel buttonPanel; 13 private ButtonGroup group; 14 private JLabel label; 15 private static final int DEFAULT_SIZE = 36; 16 17 public RadioButtonFrame() 18 { 19 // add the sample text label 20 21 label = new JLabel("The quick brown fox jumps over the lazy dog."); 22 label.setFont(new Font("Serif", Font.PLAIN, DEFAULT_SIZE)); 23 add(label, BorderLayout.CENTER); 24 25 // add the radio buttons 26 27 buttonPanel = new JPanel(); 28 group = new ButtonGroup(); 29 30 addRadioButton("Small", 8); 31 addRadioButton("Medium", 12); 32 addRadioButton("Large", 18); 33 addRadioButton("Extra large", 36); 34 35 add(buttonPanel, BorderLayout.SOUTH); 36 pack(); 37 } 38 39 /** 40 * Adds a radio button that sets the font size of the sample text. 41 * @param name the string to appear on the button 42 * @param size the font size that this button sets 43 */ 44 public void addRadioButton(String name, int size) 45 { 46 boolean selected = size == DEFAULT_SIZE; 47 JRadioButton button = new JRadioButton(name, selected); 48 group.add(button); 49 buttonPanel.add(button); 50 51 // this listener sets the label font size 52 53 ActionListener listener = event -> label.setFont(new Font("Serif", Font.PLAIN, size)); 54 55 button.addActionListener(listener); 56 } 57 }
1 package radioButton; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class RadioButtonTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new RadioButtonFrame(); 16 frame.setTitle("RadioButtonTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
测试程序5
l 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；
l 掌握边框的用法；
l 记录示例代码阅读理解中存在的问题与疑惑。
1 package border; 2 3 import java.awt.*; 4 import javax.swing.*; 5 import javax.swing.border.*; 6 7 /** 8 * A frame with radio buttons to pick a border style. 9 */ 10 public class BorderFrame extends JFrame 11 { 12 private JPanel demoPanel; 13 private JPanel buttonPanel; 14 private ButtonGroup group; 15 16 public BorderFrame() 17 { 18 demoPanel = new JPanel(); 19 buttonPanel = new JPanel(); 20 group = new ButtonGroup(); 21 22 addRadioButton("Lowered bevel", BorderFactory.createLoweredBevelBorder()); 23 addRadioButton("Raised bevel", BorderFactory.createRaisedBevelBorder()); 24 addRadioButton("Etched", BorderFactory.createEtchedBorder()); 25 addRadioButton("Line", BorderFactory.createLineBorder(Color.BLUE)); 26 addRadioButton("Matte", BorderFactory.createMatteBorder(10, 10, 10, 10, Color.BLUE)); 27 addRadioButton("Empty", BorderFactory.createEmptyBorder()); 28 29 Border etched = BorderFactory.createEtchedBorder(); 30 Border titled = BorderFactory.createTitledBorder(etched, "Border types"); 31 buttonPanel.setBorder(titled); 32 33 setLayout(new GridLayout(2, 1)); 34 add(buttonPanel); 35 add(demoPanel); 36 pack(); 37 } 38 39 public void addRadioButton(String buttonName, Border b) 40 { 41 JRadioButton button = new JRadioButton(buttonName); 42 button.addActionListener(event -> demoPanel.setBorder(b)); 43 group.add(button); 44 buttonPanel.add(button); 45 } 46 }
1 package border; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2015-06-13 8 * @author Cay Horstmann 9 */ 10 public class BorderTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new BorderFrame(); 16 frame.setTitle("BorderTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
测试程序6
l 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；
l 掌握组合框组件的用法；
l 记录示例代码阅读理解中存在的问题与疑惑。
1 package comboBox; 2 3 import java.awt.BorderLayout; 4 import java.awt.Font; 5 6 import javax.swing.JComboBox; 7 import javax.swing.JFrame; 8 import javax.swing.JLabel; 9 import javax.swing.JPanel; 10 11 /** 12 * A frame with a sample text label and a combo box for selecting font faces. 13 */ 14 public class ComboBoxFrame extends JFrame 15 { 16 private JComboBox<String> faceCombo; 17 private JLabel label; 18 private static final int DEFAULT_SIZE = 24; 19 20 public ComboBoxFrame() 21 { 22 // add the sample text label 23 24 label = new JLabel("The quick brown fox jumps over the lazy dog."); 25 label.setFont(new Font("Serif", Font.PLAIN, DEFAULT_SIZE)); 26 add(label, BorderLayout.CENTER); 27 28 // make a combo box and add face names 29 30 faceCombo = new JComboBox<>(); 31 faceCombo.addItem("Serif"); 32 faceCombo.addItem("SansSerif"); 33 faceCombo.addItem("Monospaced"); 34 faceCombo.addItem("Dialog"); 35 faceCombo.addItem("DialogInput"); 36 37 // the combo box listener changes the label font to the selected face name 38 39 faceCombo.addActionListener(event -> 40 label.setFont( 41 new Font(faceCombo.getItemAt(faceCombo.getSelectedIndex()), 42 Font.PLAIN, DEFAULT_SIZE))); 43 44 // add combo box to a panel at the frame's southern border 45 46 JPanel comboPanel = new JPanel(); 47 comboPanel.add(faceCombo); 48 add(comboPanel, BorderLayout.SOUTH); 49 pack(); 50 } 51 }
1 package comboBox; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.35 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class ComboBoxTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new ComboBoxFrame(); 16 frame.setTitle("ComboBoxTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
测试程序7
l 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；
掌握滑动条组件的用法；
l 记录示例代码阅读理解中存在的问题与疑惑。
1 package slider; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.15 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class SliderTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 SliderFrame frame = new SliderFrame(); 16 frame.setTitle("SliderTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
1 package slider; 2 3 import java.awt.*; 4 import java.util.*; 5 import javax.swing.*; 6 import javax.swing.event.*; 7 8 /** 9 * A frame with many sliders and a text field to show slider values. 10 */ 11 public class SliderFrame extends JFrame 12 { 13 private JPanel sliderPanel; 14 private JTextField textField; 15 private ChangeListener listener; 16 17 public SliderFrame() 18 { 19 sliderPanel = new JPanel(); 20 sliderPanel.setLayout(new GridBagLayout()); 21 22 // common listener for all sliders 23 listener = event -> { 24 // update text field when the slider value changes 25 JSlider source = (JSlider) event.getSource(); 26 textField.setText("" + source.getValue()); 27 }; 28 29 // add a plain slider 30 31 JSlider slider = new JSlider(); 32 addSlider(slider, "Plain"); 33 34 // add a slider with major and minor ticks 35 36 slider = new JSlider(); 37 slider.setPaintTicks(true); 38 slider.setMajorTickSpacing(20); 39 slider.setMinorTickSpacing(5); 40 addSlider(slider, "Ticks"); 41 42 // add a slider that snaps to ticks 43 44 slider = new JSlider(); 45 slider.setPaintTicks(true); 46 slider.setSnapToTicks(true); 47 slider.setMajorTickSpacing(20); 48 slider.setMinorTickSpacing(5); 49 addSlider(slider, "Snap to ticks"); 50 51 // add a slider with no track 52 53 slider = new JSlider(); 54 slider.setPaintTicks(true); 55 slider.setMajorTickSpacing(20); 56 slider.setMinorTickSpacing(5); 57 slider.setPaintTrack(false); 58 addSlider(slider, "No track"); 59 60 // add an inverted slider 61 62 slider = new JSlider(); 63 slider.setPaintTicks(true); 64 slider.setMajorTickSpacing(20); 65 slider.setMinorTickSpacing(5); 66 slider.setInverted(true); 67 addSlider(slider, "Inverted"); 68 69 // add a slider with numeric labels 70 71 slider = new JSlider(); 72 slider.setPaintTicks(true); 73 slider.setPaintLabels(true); 74 slider.setMajorTickSpacing(20); 75 slider.setMinorTickSpacing(5); 76 addSlider(slider, "Labels"); 77 78 // add a slider with alphabetic labels 79 80 slider = new JSlider(); 81 slider.setPaintLabels(true); 82 slider.setPaintTicks(true); 83 slider.setMajorTickSpacing(20); 84 slider.setMinorTickSpacing(5); 85 86 Dictionary<Integer, Component> labelTable = new Hashtable<>(); 87 labelTable.put(0, new JLabel("A")); 88 labelTable.put(20, new JLabel("B")); 89 labelTable.put(40, new JLabel("C")); 90 labelTable.put(60, new JLabel("D")); 91 labelTable.put(80, new JLabel("E")); 92 labelTable.put(100, new JLabel("F")); 93 94 slider.setLabelTable(labelTable); 95 addSlider(slider, "Custom labels"); 96 97 // add a slider with icon labels 98 99 slider = new JSlider(); 100 slider.setPaintTicks(true); 101 slider.setPaintLabels(true); 102 slider.setSnapToTicks(true); 103 slider.setMajorTickSpacing(20); 104 slider.setMinorTickSpacing(20); 105 106 labelTable = new Hashtable<Integer, Component>(); 107 108 // add card images 109 110 labelTable.put(0, new JLabel(new ImageIcon("nine.gif"))); 111 labelTable.put(20, new JLabel(new ImageIcon("ten.gif"))); 112 labelTable.put(40, new JLabel(new ImageIcon("jack.gif"))); 113 labelTable.put(60, new JLabel(new ImageIcon("queen.gif"))); 114 labelTable.put(80, new JLabel(new ImageIcon("king.gif"))); 115 labelTable.put(100, new JLabel(new ImageIcon("ace.gif"))); 116 117 slider.setLabelTable(labelTable); 118 addSlider(slider, "Icon labels"); 119 120 // add the text field that displays the slider value 121 122 textField = new JTextField(); 123 add(sliderPanel, BorderLayout.CENTER); 124 add(textField, BorderLayout.SOUTH); 125 pack(); 126 } 127 128 /** 129 * Adds a slider to the slider panel and hooks up the listener 130 * @param s the slider 131 * @param description the slider description 132 */ 133 public void addSlider(JSlider s, String description) 134 { 135 s.addChangeListener(listener); 136 JPanel panel = new JPanel(); 137 panel.add(s); 138 panel.add(new JLabel(description)); 139 panel.setAlignmentX(Component.LEFT_ALIGNMENT); 140 GridBagConstraints gbc = new GridBagConstraints(); 141 gbc.gridy = sliderPanel.getComponentCount(); 142 gbc.anchor = GridBagConstraints.WEST; 143 sliderPanel.add(panel, gbc); 144 } 145 }
测试程序8
l 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；
l 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。
l 记录示例代码阅读理解中存在的问题与疑惑。
1 package menu; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.24 2012-06-12 8 * @author Cay Horstmann 9 */ 10 public class MenuTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new MenuFrame(); 16 frame.setTitle("MenuTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
1 package menu; 2 3 import java.awt.event.*; 4 import javax.swing.*; 5 6 /** 7 * A frame with a sample menu bar. 8 */ 9 public class MenuFrame extends JFrame 10 { 11 private static final int DEFAULT_WIDTH = 300; 12 private static final int DEFAULT_HEIGHT = 200; 13 private Action saveAction; 14 private Action saveAsAction; 15 private JCheckBoxMenuItem readonlyItem; 16 private JPopupMenu popup; 17 18 /** 19 * A sample action that prints the action name to System.out 20 */ 21 class TestAction extends AbstractAction 22 { 23 public TestAction(String name) 24 { 25 super(name); 26 } 27 28 public void actionPerformed(ActionEvent event) 29 { 30 System.out.println(getValue(Action.NAME) + " selected."); 31 } 32 } 33 34 public MenuFrame() 35 { 36 setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); 37 38 JMenu fileMenu = new JMenu("File"); 39 fileMenu.add(new TestAction("New")); 40 41 // demonstrate accelerators 42 43 JMenuItem openItem = fileMenu.add(new TestAction("Open")); 44 openItem.setAccelerator(KeyStroke.getKeyStroke("ctrl O")); 45 46 fileMenu.addSeparator(); 47 48 saveAction = new TestAction("Save"); 49 JMenuItem saveItem = fileMenu.add(saveAction); 50 saveItem.setAccelerator(KeyStroke.getKeyStroke("ctrl S")); 51 52 saveAsAction = new TestAction("Save As"); 53 fileMenu.add(saveAsAction); 54 fileMenu.addSeparator(); 55 56 fileMenu.add(new AbstractAction("Exit") 57 { 58 public void actionPerformed(ActionEvent event) 59 { 60 System.exit(0); 61 } 62 }); 63 64 // demonstrate checkbox and radio button menus 65 66 readonlyItem = new JCheckBoxMenuItem("Read-only"); 67 readonlyItem.addActionListener(new ActionListener() 68 { 69 public void actionPerformed(ActionEvent event) 70 { 71 boolean saveOk = !readonlyItem.isSelected(); 72 saveAction.setEnabled(saveOk); 73 saveAsAction.setEnabled(saveOk); 74 } 75 }); 76 77 ButtonGroup group = new ButtonGroup(); 78 79 JRadioButtonMenuItem insertItem = new JRadioButtonMenuItem("Insert"); 80 insertItem.setSelected(true); 81 JRadioButtonMenuItem overtypeItem = new JRadioButtonMenuItem("Overtype"); 82 83 group.add(insertItem); 84 group.add(overtypeItem); 85 86 // demonstrate icons 87 88 Action cutAction = new TestAction("Cut"); 89 cutAction.putValue(Action.SMALL_ICON, new ImageIcon("cut.gif")); 90 Action copyAction = new TestAction("Copy"); 91 copyAction.putValue(Action.SMALL_ICON, new ImageIcon("copy.gif")); 92 Action pasteAction = new TestAction("Paste"); 93 pasteAction.putValue(Action.SMALL_ICON, new ImageIcon("paste.gif")); 94 95 JMenu editMenu = new JMenu("Edit"); 96 editMenu.add(cutAction); 97 editMenu.add(copyAction); 98 editMenu.add(pasteAction); 99 100 // demonstrate nested menus 101 102 JMenu optionMenu = new JMenu("Options"); 103 104 optionMenu.add(readonlyItem); 105 optionMenu.addSeparator(); 106 optionMenu.add(insertItem); 107 optionMenu.add(overtypeItem); 108 109 editMenu.addSeparator(); 110 editMenu.add(optionMenu); 111 112 // demonstrate mnemonics 113 114 JMenu helpMenu = new JMenu("Help"); 115 helpMenu.setMnemonic('H'); 116 117 JMenuItem indexItem = new JMenuItem("Index"); 118 indexItem.setMnemonic('I'); 119 helpMenu.add(indexItem); 120 121 // you can also add the mnemonic key to an action 122 Action aboutAction = new TestAction("About"); 123 aboutAction.putValue(Action.MNEMONIC_KEY, new Integer('A')); 124 helpMenu.add(aboutAction); 125 126 // add all top-level menus to menu bar 127 128 JMenuBar menuBar = new JMenuBar(); 129 setJMenuBar(menuBar); 130 131 menuBar.add(fileMenu); 132 menuBar.add(editMenu); 133 menuBar.add(helpMenu); 134 135 // demonstrate pop-ups 136 137 popup = new JPopupMenu(); 138 popup.add(cutAction); 139 popup.add(copyAction); 140 popup.add(pasteAction); 141 142 JPanel panel = new JPanel(); 143 panel.setComponentPopupMenu(popup); 144 add(panel); 145 } 146 }
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。
1 package toolBar; 2 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 /** 8 * A frame with a toolbar and menu for color changes. 9 */ 10 public class ToolBarFrame extends JFrame 11 { 12 private static final int DEFAULT_WIDTH = 300; 13 private static final int DEFAULT_HEIGHT = 200; 14 private JPanel panel; 15 16 public ToolBarFrame() 17 { 18 setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); 19 20 // add a panel for color change 21 22 panel = new JPanel(); 23 add(panel, BorderLayout.CENTER); 24 25 // set up actions 26 27 Action blueAction = new ColorAction("Blue", new ImageIcon("blue-ball.gif"), Color.BLUE); 28 Action yellowAction = new ColorAction("Yellow", new ImageIcon("yellow-ball.gif"), 29 Color.YELLOW); 30 Action redAction = new ColorAction("Red", new ImageIcon("red-ball.gif"), Color.RED); 31 32 Action exitAction = new AbstractAction("Exit", new ImageIcon("exit.gif")) 33 { 34 public void actionPerformed(ActionEvent event) 35 { 36 System.exit(0); 37 } 38 }; 39 exitAction.putValue(Action.SHORT_DESCRIPTION, "Exit"); 40 41 // populate toolbar 42 43 JToolBar bar = new JToolBar(); 44 bar.add(blueAction); 45 bar.add(yellowAction); 46 bar.add(redAction); 47 bar.addSeparator(); 48 bar.add(exitAction); 49 add(bar, BorderLayout.NORTH); 50 51 // populate menu 52 53 JMenu menu = new JMenu("Color"); 54 menu.add(yellowAction); 55 menu.add(blueAction); 56 menu.add(redAction); 57 menu.add(exitAction); 58 JMenuBar menuBar = new JMenuBar(); 59 menuBar.add(menu); 60 setJMenuBar(menuBar); 61 } 62 63 /** 64 * The color action sets the background of the frame to a given color. 65 */ 66 class ColorAction extends AbstractAction 67 { 68 public ColorAction(String name, Icon icon, Color c) 69 { 70 putValue(Action.NAME, name); 71 putValue(Action.SMALL_ICON, icon); 72 putValue(Action.SHORT_DESCRIPTION, name + " background"); 73 putValue("Color", c); 74 } 75 76 public void actionPerformed(ActionEvent event) 77 { 78 Color c = (Color) getValue("Color"); 79 panel.setBackground(c); 80 } 81 } 82 }
1 package toolBar; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.14 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class ToolBarTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 ToolBarFrame frame = new ToolBarFrame(); 16 frame.setTitle("ToolBarTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
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。
1 package gridbag; 2 3 import java.awt.EventQueue; 4 5 import javax.swing.JFrame; 6 7 /** 8 * @version 1.35 2015-06-12 9 * @author Cay Horstmann 10 */ 11 public class GridBagLayoutTest 12 { 13 public static void main(String[] args) 14 { 15 EventQueue.invokeLater(() -> { 16 JFrame frame = new FontFrame(); 17 frame.setTitle("GridBagLayoutTest"); 18 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 19 frame.setVisible(true); 20 }); 21 } 22 }
1 package gridbag; 2 3 import java.awt.*; 4 5 /** 6 * This class simplifies the use of the GridBagConstraints class. 7 * @version 1.01 2004-05-06 8 * @author Cay Horstmann 9 */ 10 public class GBC extends GridBagConstraints 11 { 12 /** 13 * Constructs a GBC with a given gridx and gridy position and all other grid 14 * bag constraint values set to the default. 15 * @param gridx the gridx position 16 * @param gridy the gridy position 17 */ 18 public GBC(int gridx, int gridy) 19 { 20 this.gridx = gridx; 21 this.gridy = gridy; 22 } 23 24 /** 25 * Constructs a GBC with given gridx, gridy, gridwidth, gridheight and all 26 * other grid bag constraint values set to the default. 27 * @param gridx the gridx position 28 * @param gridy the gridy position 29 * @param gridwidth the cell span in x-direction 30 * @param gridheight the cell span in y-direction 31 */ 32 public GBC(int gridx, int gridy, int gridwidth, int gridheight) 33 { 34 this.gridx = gridx; 35 this.gridy = gridy; 36 this.gridwidth = gridwidth; 37 this.gridheight = gridheight; 38 } 39 40 /** 41 * Sets the anchor. 42 * @param anchor the anchor value 43 * @return this object for further modification 44 */ 45 public GBC setAnchor(int anchor) 46 { 47 this.anchor = anchor; 48 return this; 49 } 50 51 /** 52 * Sets the fill direction. 53 * @param fill the fill direction 54 * @return this object for further modification 55 */ 56 public GBC setFill(int fill) 57 { 58 this.fill = fill; 59 return this; 60 } 61 62 /** 63 * Sets the cell weights. 64 * @param weightx the cell weight in x-direction 65 * @param weighty the cell weight in y-direction 66 * @return this object for further modification 67 */ 68 public GBC setWeight(double weightx, double weighty) 69 { 70 this.weightx = weightx; 71 this.weighty = weighty; 72 return this; 73 } 74 75 /** 76 * Sets the insets of this cell. 77 * @param distance the spacing to use in all directions 78 * @return this object for further modification 79 */ 80 public GBC setInsets(int distance) 81 { 82 this.insets = new Insets(distance, distance, distance, distance); 83 return this; 84 } 85 86 /** 87 * Sets the insets of this cell. 88 * @param top the spacing to use on top 89 * @param left the spacing to use to the left 90 * @param bottom the spacing to use on the bottom 91 * @param right the spacing to use to the right 92 * @return this object for further modification 93 */ 94 public GBC setInsets(int top, int left, int bottom, int right) 95 { 96 this.insets = new Insets(top, left, bottom, right); 97 return this; 98 } 99 100 /** 101 * Sets the internal padding 102 * @param ipadx the internal padding in x-direction 103 * @param ipady the internal padding in y-direction 104 * @return this object for further modification 105 */ 106 public GBC setIpad(int ipadx, int ipady) 107 { 108 this.ipadx = ipadx; 109 this.ipady = ipady; 110 return this; 111 } 112 }
1 package gridbag; 2 3 import java.awt.Font; 4 import java.awt.GridBagLayout; 5 import java.awt.event.ActionListener; 6 7 import javax.swing.BorderFactory; 8 import javax.swing.JCheckBox; 9 import javax.swing.JComboBox; 10 import javax.swing.JFrame; 11 import javax.swing.JLabel; 12 import javax.swing.JTextArea; 13 14 /** 15 * A frame that uses a grid bag layout to arrange font selection components. 16 */ 17 public class FontFrame extends JFrame 18 { 19 public static final int TEXT_ROWS = 10; 20 public static final int TEXT_COLUMNS = 20; 21 22 private JComboBox<String> face; 23 private JComboBox<Integer> size; 24 private JCheckBox bold; 25 private JCheckBox italic; 26 private JTextArea sample; 27 28 public FontFrame() 29 { 30 GridBagLayout layout = new GridBagLayout(); 31 setLayout(layout); 32 33 ActionListener listener = event -> updateSample(); 34 35 // construct components 36 37 JLabel faceLabel = new JLabel("Face: "); 38 39 face = new JComboBox<>(new String[] { "Serif", "SansSerif", "Monospaced", 40 "Dialog", "DialogInput" }); 41 42 face.addActionListener(listener); 43 44 JLabel sizeLabel = new JLabel("Size: "); 45 46 size = new JComboBox<>(new Integer[] { 8, 10, 12, 15, 18, 24, 36, 48 }); 47 48 size.addActionListener(listener); 49 50 bold = new JCheckBox("Bold"); 51 bold.addActionListener(listener); 52 53 italic = new JCheckBox("Italic"); 54 italic.addActionListener(listener); 55 56 sample = new JTextArea(TEXT_ROWS, TEXT_COLUMNS); 57 sample.setText("The quick brown fox jumps over the lazy dog"); 58 sample.setEditable(false); 59 sample.setLineWrap(true); 60 sample.setBorder(BorderFactory.createEtchedBorder()); 61 62 // add components to grid, using GBC convenience class 63 64 add(faceLabel, new GBC(0, 0).setAnchor(GBC.EAST)); 65 add(face, new GBC(1, 0).setFill(GBC.HORIZONTAL).setWeight(100, 0) 66 .setInsets(1)); 67 add(sizeLabel, new GBC(0, 1).setAnchor(GBC.EAST)); 68 add(size, new GBC(1, 1).setFill(GBC.HORIZONTAL).setWeight(100, 0) 69 .setInsets(1)); 70 add(bold, new GBC(0, 2, 2, 1).setAnchor(GBC.CENTER).setWeight(100, 100)); 71 add(italic, new GBC(0, 3, 2, 1).setAnchor(GBC.CENTER).setWeight(100, 100)); 72 add(sample, new GBC(2, 0, 1, 4).setFill(GBC.BOTH).setWeight(100, 100)); 73 pack(); 74 updateSample(); 75 } 76 77 public void updateSample() 78 { 79 String fontFace = (String) face.getSelectedItem(); 80 int fontStyle = (bold.isSelected() ? Font.BOLD : 0) 81 + (italic.isSelected() ? Font.ITALIC : 0); 82 int fontSize = size.getItemAt(size.getSelectedIndex()); 83 Font font = new Font(fontFace, fontStyle, fontSize); 84 sample.setFont(font); 85 sample.repaint(); 86 } 87 }
1 package groupLayout; 2 3 import java.awt.EventQueue; 4 5 import javax.swing.JFrame; 6 7 /** 8 * @version 1.01 2015-06-12 9 * @author Cay Horstmann 10 */ 11 public class GroupLayoutTest 12 { 13 public static void main(String[] args) 14 { 15 EventQueue.invokeLater(() -> { 16 JFrame frame = new FontFrame(); 17 frame.setTitle("GroupLayoutTest"); 18 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 19 frame.setVisible(true); 20 }); 21 } 22 }
1 package groupLayout; 2 3 import java.awt.Font; 4 import java.awt.event.ActionListener; 5 6 import javax.swing.BorderFactory; 7 import javax.swing.GroupLayout; 8 import javax.swing.JCheckBox; 9 import javax.swing.JComboBox; 10 import javax.swing.JFrame; 11 import javax.swing.JLabel; 12 import javax.swing.JScrollPane; 13 import javax.swing.JTextArea; 14 import javax.swing.LayoutStyle; 15 import javax.swing.SwingConstants; 16 17 /** 18 * A frame that uses a group layout to arrange font selection components. 19 */ 20 public class FontFrame extends JFrame 21 { 22 public static final int TEXT_ROWS = 10; 23 public static final int TEXT_COLUMNS = 20; 24 25 private JComboBox<String> face; 26 private JComboBox<Integer> size; 27 private JCheckBox bold; 28 private JCheckBox italic; 29 private JScrollPane pane; 30 private JTextArea sample; 31 32 public FontFrame() 33 { 34 ActionListener listener = event -> updateSample(); 35 36 // construct components 37 38 JLabel faceLabel = new JLabel("Face: "); 39 40 face = new JComboBox<>(new String[] { "Serif", "SansSerif", "Monospaced", "Dialog", 41 "DialogInput" }); 42 43 face.addActionListener(listener); 44 45 JLabel sizeLabel = new JLabel("Size: "); 46 47 size = new JComboBox<>(new Integer[] { 8, 10, 12, 15, 18, 24, 36, 48 }); 48 49 size.addActionListener(listener); 50 51 bold = new JCheckBox("Bold"); 52 bold.addActionListener(listener); 53 54 italic = new JCheckBox("Italic"); 55 italic.addActionListener(listener); 56 57 sample = new JTextArea(TEXT_ROWS, TEXT_COLUMNS); 58 sample.setText("The quick brown fox jumps over the lazy dog"); 59 sample.setEditable(false); 60 sample.setLineWrap(true); 61 sample.setBorder(BorderFactory.createEtchedBorder()); 62 63 pane = new JScrollPane(sample); 64 65 GroupLayout layout = new GroupLayout(getContentPane()); 66 setLayout(layout); 67 layout.setHorizontalGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING) 68 .addGroup( 69 layout.createSequentialGroup().addContainerGap().addGroup( 70 layout.createParallelGroup(GroupLayout.Alignment.LEADING).addGroup( 71 GroupLayout.Alignment.TRAILING, 72 layout.createSequentialGroup().addGroup( 73 layout.createParallelGroup(GroupLayout.Alignment.TRAILING) 74 .addComponent(faceLabel).addComponent(sizeLabel)) 75 .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED) 76 .addGroup( 77 layout.createParallelGroup( 78 GroupLayout.Alignment.LEADING, false) 79 .addComponent(size).addComponent(face))) 80 .addComponent(italic).addComponent(bold)).addPreferredGap( 81 LayoutStyle.ComponentPlacement.RELATED).addComponent(pane) 82 .addContainerGap())); 83 84 layout.linkSize(SwingConstants.HORIZONTAL, new java.awt.Component[] { face, size }); 85 86 layout.setVerticalGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING) 87 .addGroup( 88 layout.createSequentialGroup().addContainerGap().addGroup( 89 layout.createParallelGroup(GroupLayout.Alignment.LEADING).addComponent( 90 pane, GroupLayout.Alignment.TRAILING).addGroup( 91 layout.createSequentialGroup().addGroup( 92 layout.createParallelGroup(GroupLayout.Alignment.BASELINE) 93 .addComponent(face).addComponent(faceLabel)) 94 .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED) 95 .addGroup( 96 layout.createParallelGroup( 97 GroupLayout.Alignment.BASELINE).addComponent(size) 98 .addComponent(sizeLabel)).addPreferredGap( 99 LayoutStyle.ComponentPlacement.RELATED).addComponent( 100 italic, GroupLayout.DEFAULT_SIZE, 101 GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) 102 .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED) 103 .addComponent(bold, GroupLayout.DEFAULT_SIZE, 104 GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))) 105 .addContainerGap())); 106 pack(); 107 } 108 109 public void updateSample() 110 { 111 String fontFace = (String) face.getSelectedItem(); 112 int fontStyle = (bold.isSelected() ? Font.BOLD : 0) 113 + (italic.isSelected() ? Font.ITALIC : 0); 114 int fontSize = size.getItemAt(size.getSelectedIndex()); 115 Font font = new Font(fontFace, fontStyle, fontSize); 116 sample.setFont(font); 117 sample.repaint(); 118 } 119 }
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。
1 package circleLayout; 2 3 import java.awt.*; 4 5 /** 6 * A layout manager that lays out components along a circle. 7 */ 8 public class CircleLayout implements LayoutManager 9 { 10 private int minWidth = 0;//定义最小宽度； 11 private int minHeight = 0;//定义最小高度； 12 private int preferredWidth = 0;//定义首选宽度； 13 private int preferredHeight = 0;//定义首选高度； 14 private boolean sizesSet = false;//定义布尔值sizesSet，且将其是指为FALSE； 15 private int maxComponentWidth = 0;//定义组件的最大宽度； 16 private int maxComponentHeight = 0;//定义组件的最大高度； 17 18 public void addLayoutComponent(String name, Component comp)//将组件添加到布局中的方法（方法为空） 19 { 20 } 21 22 public void removeLayoutComponent(Component comp)//从本布局中删除一个组件的方法（方法为空） 23 { 24 } 25 26 public void setSizes(Container parent)//构造容器的大小的方法 27 { 28 if (sizesSet) return; 29 int n = parent.getComponentCount(); 30 31 preferredWidth = 0; //首选宽度初始化为0； 32 preferredHeight = 0;//首选高度初始化为0； 33 minWidth = 0;//最小宽度初始化为0； 34 minHeight = 0;//最小宽度初始化为0； 35 maxComponentWidth = 0;//组件的最大宽度初始化为0； 36 maxComponentHeight = 0;//组件的最大高度初始化为0； 37 38 // 计算最大分量宽度和高度 39 //将首选大小设置为组件大小的和 40 for (int i = 0; i < n; i++) 41 { 42 Component c = parent.getComponent(i); 43 if (c.isVisible()) 44 { 45 Dimension d = c.getPreferredSize(); 46 maxComponentWidth = Math.max(maxComponentWidth, d.width);//使用math方法计算组件的最大宽度 47 maxComponentHeight = Math.max(maxComponentHeight, d.height);//使用math方法计算组件的最大高度 48 preferredWidth += d.width; 49 preferredHeight += d.height; 50 } 51 } 52 minWidth = preferredWidth / 2;//最小宽度是首选宽度的一半 53 minHeight = preferredHeight / 2;//最小高度是首选高度的一半 54 sizesSet = true; 55 } 56 57 public Dimension preferredLayoutSize(Container parent)//首选维度大小的构造方法 58 { 59 setSizes(parent); 60 Insets insets = parent.getInsets(); 61 int width = preferredWidth + insets.left + insets.right; 62 int height = preferredHeight + insets.top + insets.bottom; 63 return new Dimension(width, height); 64 } 65 66 public Dimension minimumLayoutSize(Container parent)//最小维度大小的构造方法 67 { 68 setSizes(parent); 69 Insets insets = parent.getInsets(); 70 int width = minWidth + insets.left + insets.right; 71 int height = minHeight + insets.top + insets.bottom; 72 return new Dimension(width, height); 73 } 74 75 public void layoutContainer(Container parent)//容器的构造方法 76 { 77 setSizes(parent); 78 79 // 计算圆的中心 80 81 Insets insets = parent.getInsets(); 82 int containerWidth = parent.getSize().width - insets.left - insets.right; 83 int containerHeight = parent.getSize().height - insets.top - insets.bottom; 84 85 int xcenter = insets.left + containerWidth / 2;//计算中心位置横坐标 86 int ycenter = insets.top + containerHeight / 2;//计算中心位置纵坐标 87 88 // 计算圆的半径 89 90 int xradius = (containerWidth - maxComponentWidth) / 2;//计算圆半径横坐标 91 int yradius = (containerHeight - maxComponentHeight) / 2;//计算圆半径纵坐标 92 int radius = Math.min(xradius, yradius); 93 94 // 沿圆布局组件 95 96 int n = parent.getComponentCount(); 97 for (int i = 0; i < n; i++) 98 { 99 Component c = parent.getComponent(i); 100 if (c.isVisible()) 101 { 102 double angle = 2 * Math.PI * i / n; 103 104 // 组件中心点 105 int x = xcenter + (int) (Math.cos(angle) * radius); 106 int y = ycenter + (int) (Math.sin(angle) * radius); 107 108 // 移动组件，使其中心为（x，y） 109 // 尺寸为首选尺寸 110 Dimension d = c.getPreferredSize(); 111 c.setBounds(x - d.width / 2, y - d.height / 2, d.width, d.height); 112 } 113 } 114 } 115 }
1 package circleLayout; 2 3 import javax.swing.*; 4 5 /** 6 * A frame that shows buttons arranged along a circle. 7 */ 8 public class CircleLayoutFrame extends JFrame//CircleLayoutFrame类继承JFrame类 9 { 10 public CircleLayoutFrame() 11 { 12 setLayout(new CircleLayout());//设置布局为环形布局 13 add(new JButton("Yellow"));//添加一个名为“Yellow”的按钮 14 add(new JButton("Blue"));//添加一个名为“Blue”的按钮 15 add(new JButton("Red"));//添加一个名为“Red”的按钮 16 add(new JButton("Green"));//添加一个名为“Green”的按钮 17 add(new JButton("Orange"));//添加一个名为“Orange”的按钮 18 add(new JButton("Fuchsia"));//添加一个名为“Fuchsia”的按钮 19 add(new JButton("Indigo"));//添加一个名为“Indigo”的按钮 20 pack(); 21 } 22 }
1 package circleLayout; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.33 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class CircleLayoutTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new CircleLayoutFrame();//创建一个框架 16 frame.setTitle("CircleLayoutTest");//框架标题为“CircleLayoutTest” 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//点击框架右上角的关闭按钮车能续结束运行 18 frame.setVisible(true);//将框架设置为可见 19 }); 20 } 21 }
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。
1 package optionDialog; 2 3 import javax.swing.*; 4 5 /** 6 * A panel with radio buttons inside a titled border. 7 */ 8 public class ButtonPanel extends JPanel 9 { 10 private ButtonGroup group; 11 12 /** 13 * Constructs a button panel. 14 * @param title the title shown in the border 15 * @param options an array of radio button labels 16 */ 17 public ButtonPanel(String title, String... options) 18 { 19 setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(), title)); 20 setLayout(new BoxLayout(this, BoxLayout.Y_AXIS)); 21 group = new ButtonGroup(); 22 23 // make one radio button for each option 24 for (String option : options) 25 { 26 JRadioButton b = new JRadioButton(option); 27 b.setActionCommand(option); 28 add(b); 29 group.add(b); 30 b.setSelected(option == options[0]); 31 } 32 } 33 34 /** 35 * Gets the currently selected option. 36 * @return the label of the currently selected radio button. 37 */ 38 public String getSelection() 39 { 40 return group.getSelection().getActionCommand(); 41 } 42 }
1 package optionDialog; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class OptionDialogTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new OptionDialogFrame(); 16 frame.setTitle("OptionDialogTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
1 package optionDialog; 2 3 import java.awt.*; 4 import java.awt.event.*; 5 import java.awt.geom.*; 6 import java.util.*; 7 import javax.swing.*; 8 9 /** 10 * A frame that contains settings for selecting various option dialogs. 11 */ 12 public class OptionDialogFrame extends JFrame 13 { 14 private ButtonPanel typePanel; 15 private ButtonPanel messagePanel; 16 private ButtonPanel messageTypePanel; 17 private ButtonPanel optionTypePanel; 18 private ButtonPanel optionsPanel; 19 private ButtonPanel inputPanel; 20 private String messageString = "Message"; 21 private Icon messageIcon = new ImageIcon("blue-ball.gif"); 22 private Object messageObject = new Date(); 23 private Component messageComponent = new SampleComponent(); 24 25 public OptionDialogFrame() 26 { 27 JPanel gridPanel = new JPanel(); 28 gridPanel.setLayout(new GridLayout(2, 3)); 29 30 typePanel = new ButtonPanel("Type", "Message", "Confirm", "Option", "Input"); 31 messageTypePanel = new ButtonPanel("Message Type", "ERROR_MESSAGE", "INFORMATION_MESSAGE", 32 "WARNING_MESSAGE", "QUESTION_MESSAGE", "PLAIN_MESSAGE"); 33 messagePanel = new ButtonPanel("Message", "String", "Icon", "Component", "Other", 34 "Object[]"); 35 optionTypePanel = new ButtonPanel("Confirm", "DEFAULT_OPTION", "YES_NO_OPTION", 36 "YES_NO_CANCEL_OPTION", "OK_CANCEL_OPTION"); 37 optionsPanel = new ButtonPanel("Option", "String[]", "Icon[]", "Object[]"); 38 inputPanel = new ButtonPanel("Input", "Text field", "Combo box"); 39 40 gridPanel.add(typePanel); 41 gridPanel.add(messageTypePanel); 42 gridPanel.add(messagePanel); 43 gridPanel.add(optionTypePanel); 44 gridPanel.add(optionsPanel); 45 gridPanel.add(inputPanel); 46 47 // add a panel with a Show button 48 49 JPanel showPanel = new JPanel(); 50 JButton showButton = new JButton("Show"); 51 showButton.addActionListener(new ShowAction()); 52 showPanel.add(showButton); 53 54 add(gridPanel, BorderLayout.CENTER); 55 add(showPanel, BorderLayout.SOUTH); 56 pack(); 57 } 58 59 /** 60 * Gets the currently selected message. 61 * @return a string, icon, component, or object array, depending on the Message panel selection 62 */ 63 public Object getMessage() 64 { 65 String s = messagePanel.getSelection(); 66 if (s.equals("String")) return messageString; 67 else if (s.equals("Icon")) return messageIcon; 68 else if (s.equals("Component")) return messageComponent; 69 else if (s.equals("Object[]")) return new Object[] { messageString, messageIcon, 70 messageComponent, messageObject }; 71 else if (s.equals("Other")) return messageObject; 72 else return null; 73 } 74 75 /** 76 * Gets the currently selected options. 77 * @return an array of strings, icons, or objects, depending on the Option panel selection 78 */ 79 public Object[] getOptions() 80 { 81 String s = optionsPanel.getSelection(); 82 if (s.equals("String[]")) return new String[] { "Yellow", "Blue", "Red" }; 83 else if (s.equals("Icon[]")) return new Icon[] { new ImageIcon("yellow-ball.gif"), 84 new ImageIcon("blue-ball.gif"), new ImageIcon("red-ball.gif") }; 85 else if (s.equals("Object[]")) return new Object[] { messageString, messageIcon, 86 messageComponent, messageObject }; 87 else return null; 88 } 89 90 /** 91 * Gets the selected message or option type 92 * @param panel the Message Type or Confirm panel 93 * @return the selected XXX_MESSAGE or XXX_OPTION constant from the JOptionPane class 94 */ 95 public int getType(ButtonPanel panel) 96 { 97 String s = panel.getSelection(); 98 try 99 { 100 return JOptionPane.class.getField(s).getInt(null); 101 } 102 catch (Exception e) 103 { 104 return -1; 105 } 106 } 107 108 /** 109 * The action listener for the Show button shows a Confirm, Input, Message, or Option dialog 110 * depending on the Type panel selection. 111 */ 112 private class ShowAction implements ActionListener 113 { 114 public void actionPerformed(ActionEvent event) 115 { 116 if (typePanel.getSelection().equals("Confirm")) JOptionPane.showConfirmDialog( 117 OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel), 118 getType(messageTypePanel)); 119 else if (typePanel.getSelection().equals("Input")) 120 { 121 if (inputPanel.getSelection().equals("Text field")) JOptionPane.showInputDialog( 122 OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel)); 123 else JOptionPane.showInputDialog(OptionDialogFrame.this, getMessage(), "Title", 124 getType(messageTypePanel), null, new String[] { "Yellow", "Blue", "Red" }, 125 "Blue"); 126 } 127 else if (typePanel.getSelection().equals("Message")) JOptionPane.showMessageDialog( 128 OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel)); 129 else if (typePanel.getSelection().equals("Option")) JOptionPane.showOptionDialog( 130 OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel), 131 getType(messageTypePanel), null, getOptions(), getOptions()[0]); 132 } 133 } 134 } 135 136 /** 137 * A component with a painted surface 138 */ 139 140 class SampleComponent extends JComponent 141 { 142 public void paintComponent(Graphics g) 143 { 144 Graphics2D g2 = (Graphics2D) g; 145 Rectangle2D rect = new Rectangle2D.Double(0, 0, getWidth() - 1, getHeight() - 1); 146 g2.setPaint(Color.YELLOW); 147 g2.fill(rect); 148 g2.setPaint(Color.BLUE); 149 g2.draw(rect); 150 } 151 152 public Dimension getPreferredSize() 153 { 154 return new Dimension(10, 10); 155 } 156 }
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。
1 package dialog; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2012-06-12 8 * @author Cay Horstmann 9 */ 10 public class DialogTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new DialogFrame(); 16 frame.setTitle("DialogTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
1 package dialog; 2 3 import javax.swing.JFrame; 4 import javax.swing.JMenu; 5 import javax.swing.JMenuBar; 6 import javax.swing.JMenuItem; 7 8 /** 9 * A frame with a menu whose File->About action shows a dialog. 10 */ 11 public class DialogFrame extends JFrame 12 { 13 private static final int DEFAULT_WIDTH = 300; 14 private static final int DEFAULT_HEIGHT = 200; 15 private AboutDialog dialog; 16 17 public DialogFrame() 18 { 19 setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); 20 21 // Construct a File menu. 22 23 JMenuBar menuBar = new JMenuBar(); 24 setJMenuBar(menuBar); 25 JMenu fileMenu = new JMenu("File"); 26 menuBar.add(fileMenu); 27 28 // Add About and Exit menu items. 29 30 // The About item shows the About dialog. 31 32 JMenuItem aboutItem = new JMenuItem("About"); 33 aboutItem.addActionListener(event -> { 34 if (dialog == null) // first time 35 dialog = new AboutDialog(DialogFrame.this); 36 dialog.setVisible(true); // pop up dialog 37 }); 38 fileMenu.add(aboutItem); 39 40 // The Exit item exits the program. 41 42 JMenuItem exitItem = new JMenuItem("Exit"); 43 exitItem.addActionListener(event -> System.exit(0)); 44 fileMenu.add(exitItem); 45 } 46 }
1 package dialog; 2 3 import java.awt.BorderLayout; 4 5 import javax.swing.JButton; 6 import javax.swing.JDialog; 7 import javax.swing.JFrame; 8 import javax.swing.JLabel; 9 import javax.swing.JPanel; 10 11 /** 12 * A sample modal dialog that displays a message and waits for the user to click the OK button. 13 */ 14 public class AboutDialog extends JDialog 15 { 16 public AboutDialog(JFrame owner) 17 { 18 super(owner, "About DialogTest", true); 19 20 // add HTML label to center 21 22 add( 23 new JLabel( 24 "<html><h1><i>Core Java</i></h1><hr>By Cay Horstmann</html>"), 25 BorderLayout.CENTER); 26 27 // OK button closes the dialog 28 29 JButton ok = new JButton("OK"); 30 ok.addActionListener(event -> setVisible(false)); 31 32 // add OK button to southern border 33 34 JPanel panel = new JPanel(); 35 panel.add(ok); 36 add(panel, BorderLayout.SOUTH); 37 38 pack(); 39 } 40 }
测试程序14
l 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；
l 掌握对话框的数据交换用法;
l 记录示例代码阅读理解中存在的问题与疑惑。
1 package dataExchange; 2 3 /** 4 * A user has a name and password. For security reasons, the password is stored as a char[], not a 5 * String. 6 */ 7 public class User 8 { 9 private String name; 10 private char[] password; 11 12 public User(String aName, char[] aPassword) 13 { 14 name = aName; 15 password = aPassword; 16 } 17 18 public String getName() 19 { 20 return name; 21 } 22 23 public char[] getPassword() 24 { 25 return password; 26 } 27 28 public void setName(String aName) 29 { 30 name = aName; 31 } 32 33 public void setPassword(char[] aPassword) 34 { 35 password = aPassword; 36 } 37 }
1 package dataExchange; 2 3 import java.awt.BorderLayout; 4 import java.awt.Component; 5 import java.awt.Frame; 6 import java.awt.GridLayout; 7 8 import javax.swing.JButton; 9 import javax.swing.JDialog; 10 import javax.swing.JLabel; 11 import javax.swing.JPanel; 12 import javax.swing.JPasswordField; 13 import javax.swing.JTextField; 14 import javax.swing.SwingUtilities; 15 16 /** 17 * A password chooser that is shown inside a dialog 18 */ 19 public class PasswordChooser extends JPanel 20 { 21 private JTextField username; 22 private JPasswordField password; 23 private JButton okButton; 24 private boolean ok; 25 private JDialog dialog; 26 27 public PasswordChooser() 28 { 29 setLayout(new BorderLayout()); 30 31 // construct a panel with user name and password fields 32 33 JPanel panel = new JPanel(); 34 panel.setLayout(new GridLayout(2, 2)); 35 panel.add(new JLabel("User name:")); 36 panel.add(username = new JTextField("")); 37 panel.add(new JLabel("Password:")); 38 panel.add(password = new JPasswordField("")); 39 add(panel, BorderLayout.CENTER); 40 41 // create Ok and Cancel buttons that terminate the dialog 42 43 okButton = new JButton("Ok"); 44 okButton.addActionListener(event -> { 45 ok = true; 46 dialog.setVisible(false); 47 }); 48 49 JButton cancelButton = new JButton("Cancel"); 50 cancelButton.addActionListener(event -> dialog.setVisible(false)); 51 52 // add buttons to southern border 53 54 JPanel buttonPanel = new JPanel(); 55 buttonPanel.add(okButton); 56 buttonPanel.add(cancelButton); 57 add(buttonPanel, BorderLayout.SOUTH); 58 } 59 60 /** 61 * Sets the dialog defaults. 62 * @param u the default user information 63 */ 64 public void setUser(User u) 65 { 66 username.setText(u.getName()); 67 } 68 69 /** 70 * Gets the dialog entries. 71 * @return a User object whose state represents the dialog entries 72 */ 73 public User getUser() 74 { 75 return new User(username.getText(), password.getPassword()); 76 } 77 78 /** 79 * Show the chooser panel in a dialog 80 * @param parent a component in the owner frame or null 81 * @param title the dialog window title 82 */ 83 public boolean showDialog(Component parent, String title) 84 { 85 ok = false; 86 87 // locate the owner frame 88 89 Frame owner = null; 90 if (parent instanceof Frame) 91 owner = (Frame) parent; 92 else 93 owner = (Frame) SwingUtilities.getAncestorOfClass(Frame.class, parent); 94 95 // if first time, or if owner has changed, make new dialog 96 97 if (dialog == null || dialog.getOwner() != owner) 98 { 99 dialog = new JDialog(owner, true); 100 dialog.add(this); 101 dialog.getRootPane().setDefaultButton(okButton); 102 dialog.pack(); 103 } 104 105 // set title and show dialog 106 107 dialog.setTitle(title); 108 dialog.setVisible(true); 109 return ok; 110 } 111 }
1 package dataExchange; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.34 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class DataExchangeTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new DataExchangeFrame(); 16 frame.setTitle("DataExchangeTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
1 package dataExchange; 2 3 import java.awt.*; 4 import java.awt.event.*; 5 import javax.swing.*; 6 7 /** 8 * A frame with a menu whose File->Connect action shows a password dialog. 9 */ 10 public class DataExchangeFrame extends JFrame 11 { 12 public static final int TEXT_ROWS = 20; 13 public static final int TEXT_COLUMNS = 40; 14 private PasswordChooser dialog = null; 15 private JTextArea textArea; 16 17 public DataExchangeFrame() 18 { 19 // construct a File menu 20 21 JMenuBar mbar = new JMenuBar(); 22 setJMenuBar(mbar); 23 JMenu fileMenu = new JMenu("File"); 24 mbar.add(fileMenu); 25 26 // add Connect and Exit menu items 27 28 JMenuItem connectItem = new JMenuItem("Connect"); 29 connectItem.addActionListener(new ConnectAction()); 30 fileMenu.add(connectItem); 31 32 // The Exit item exits the program 33 34 JMenuItem exitItem = new JMenuItem("Exit"); 35 exitItem.addActionListener(event -> System.exit(0)); 36 fileMenu.add(exitItem); 37 38 textArea = new JTextArea(TEXT_ROWS, TEXT_COLUMNS); 39 add(new JScrollPane(textArea), BorderLayout.CENTER); 40 pack(); 41 } 42 43 /** 44 * The Connect action pops up the password dialog. 45 */ 46 private class ConnectAction implements ActionListener 47 { 48 public void actionPerformed(ActionEvent event) 49 { 50 // if first time, construct dialog 51 52 if (dialog == null) dialog = new PasswordChooser(); 53 54 // set default values 55 dialog.setUser(new User("yourname", null)); 56 57 // pop up dialog 58 if (dialog.showDialog(DataExchangeFrame.this, "Connect")) 59 { 60 // if accepted, retrieve user input 61 User u = dialog.getUser(); 62 textArea.append("user name = " + u.getName() + ", password = " 63 + (new String(u.getPassword())) + "\n"); 64 } 65 } 66 } 67 }
测试程序15
l 在elipse IDE中调试运行教材556页程序12-21、12-2212-23，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。
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。
l 记录示例代码阅读理解中存在的问题与疑惑。
1 package colorChooser; 2 3 import java.awt.*; 4 import javax.swing.*; 5 6 /** 7 * @version 1.04 2015-06-12 8 * @author Cay Horstmann 9 */ 10 public class ColorChooserTest 11 { 12 public static void main(String[] args) 13 { 14 EventQueue.invokeLater(() -> { 15 JFrame frame = new ColorChooserFrame(); 16 frame.setTitle("ColorChooserTest"); 17 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 18 frame.setVisible(true); 19 }); 20 } 21 }
1 package colorChooser; 2 3 import java.awt.Color; 4 import java.awt.Frame; 5 import java.awt.event.ActionEvent; 6 import java.awt.event.ActionListener; 7 8 import javax.swing.JButton; 9 import javax.swing.JColorChooser; 10 import javax.swing.JDialog; 11 import javax.swing.JPanel; 12 13 /** 14 * A panel with buttons to pop up three types of color choosers 15 */ 16 public class ColorChooserPanel extends JPanel 17 { 18 public ColorChooserPanel() 19 { 20 JButton modalButton = new JButton("Modal"); 21 modalButton.addActionListener(new ModalListener()); 22 add(modalButton); 23 24 JButton modelessButton = new JButton("Modeless"); 25 modelessButton.addActionListener(new ModelessListener()); 26 add(modelessButton); 27 28 JButton immediateButton = new JButton("Immediate"); 29 immediateButton.addActionListener(new ImmediateListener()); 30 add(immediateButton); 31 } 32 33 /** 34 * This listener pops up a modal color chooser 35 */ 36 private class ModalListener implements ActionListener 37 { 38 public void actionPerformed(ActionEvent event) 39 { 40 Color defaultColor = getBackground(); 41 Color selected = JColorChooser.showDialog(ColorChooserPanel.this, "Set background", 42 defaultColor); 43 if (selected != null) setBackground(selected); 44 } 45 } 46 47 /** 48 * This listener pops up a modeless color chooser. The panel color is changed when the user 49 * clicks the OK button. 50 */ 51 private class ModelessListener implements ActionListener 52 { 53 private JDialog dialog; 54 private JColorChooser chooser; 55 56 public ModelessListener() 57 { 58 chooser = new JColorChooser(); 59 dialog = JColorChooser.createDialog(ColorChooserPanel.this, "Background Color", 60 false /* not modal */, chooser, 61 event -> setBackground(chooser.getColor()), 62 null /* no Cancel button listener */); 63 } 64 65 public void actionPerformed(ActionEvent event) 66 { 67 chooser.setColor(getBackground()); 68 dialog.setVisible(true); 69 } 70 } 71 72 /** 73 * This listener pops up a modeless color chooser. The panel color is changed immediately when 74 * the user picks a new color. 75 */ 76 private class ImmediateListener implements ActionListener 77 { 78 private JDialog dialog; 79 private JColorChooser chooser; 80 81 public ImmediateListener() 82 { 83 chooser = new JColorChooser(); 84 chooser.getSelectionModel().addChangeListener( 85 event -> setBackground(chooser.getColor())); 86 87 dialog = new JDialog((Frame) null, false /* not modal */); 88 dialog.add(chooser); 89 dialog.pack(); 90 } 91 92 public void actionPerformed(ActionEvent event) 93 { 94 chooser.setColor(getBackground()); 95 dialog.setVisible(true); 96 } 97 } 98 }
1 package colorChooser; 2 3 import javax.swing.*; 4 5 /** 6 * A frame with a color chooser panel 7 */ 8 public class ColorChooserFrame extends JFrame 9 { 10 private static final int DEFAULT_WIDTH = 300; 11 private static final int DEFAULT_HEIGHT = 200; 12 13 public ColorChooserFrame() 14 { 15 setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); 16 17 // add color chooser panel to frame 18 19 ColorChooserPanel panel = new ColorChooserPanel(); 20 add(panel); 21 } 22 }
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。
实验3：组间协同学习：在本班课程QQ群内，各位同学对实验1中存在的问题进行提问，提问时注明实验1中的测试程序编号，负责对应程序的小组需及时对群内提问进行回答。
实验总结：在学习了十一章的基础上，通过对本章的学习，对用户界面有了更加复杂的设计，是的用户界面更加美观，功能更更加丰富，学习了多种布局方式
（1）FlowLayout: 流布局(Applet和Panel的默认布局管理器）
（2）BorderLayout:边框布局( Window、Frame和Dialog的默认布局管理器）
（3）GridLayout: 网格布局
（4）GridBagLayout: 网格组布局
（5）CardLayout :卡片布局
除此之外，通过协同合作学习了环形布局管理器，用户通过计算圆的圆心坐标，以及半径长度，自定义按钮的放置位置