• 201871010118-唐敬博 《面向对象程序设计(java)》第十五周学习总结


    博文正文开头格式:(2分)

    项目

    内容

    这个作业属于哪个课程

    <https://www.cnblogs.com/nwnu-daizh/>

    这个作业的要求在哪里

    <https://www.cnblogs.com/zyja/p/11963340.html>

    作业学习目标

     

    (1) 掌握菜单组件用途及常用API;

    (2) 掌握对话框组件用途及常用API;

    (3) 学习设计简单应用程序的GUI。

     

    随笔博文正文内容包括:

    第一部分:总结菜单、对话框两类组件用途及常用API(30分)

     

    菜单条、菜单和菜单项

     

    下拉式菜单通过出现在菜单条上的名字可视化表示,菜单条(JMenuBar)通常出现在JFrame的顶部,一个菜单条显示多个下拉式菜单的名字。可以用两种方式来激活下拉式菜单。一种是按下鼠标的按钮,并保持按下状态,移动鼠标,直至释放鼠标完成选择,高亮度显示的菜单项即为所选择的。另一种方式是当光标位于菜单条中的菜单名上时,点击鼠标,在这种情况下,菜单会展开,且高亮度显示菜单项。

    一个菜单条可以放多个菜单(JMenu),每个菜单又可以有许多菜单项(JMenuItem)。例如,Eclipse环境的菜单条有File、Edit、Source、Refactor等菜单,每个菜单又有许多菜单项。例如,File菜单有New、Open File、Close 、Close All等菜单项。

    向窗口增设菜单的方法是:先创建一个菜单条对象,然后再创建若干菜单对象,把这些菜单对象放在菜单条里,再按要求为每个菜单对象添加菜单项。
    菜单中的菜单项也可以是一个完整的菜单。由于菜单项又可以是另一个完整菜单,因此可以构造一个层次状菜单结构。

    1.菜单条
    类JMenuBar的实例就是菜单条。例如,以下代码创建菜单条对象menubar:
        JMenuBar menubar = new JMenuBar();
    在窗口中增设菜单条,必须使用JFrame类中的setJMenuBar()方法。例如,代码:
        setJMenuBar(menubar);

    类JMenuBar的常用方法有:

     

    1. add(JMenu m):将菜单m加入到菜单条中。
    2. countJMenus():获得菜单条中菜单条数。
    3. getJMenu(int p):取得菜单条中的菜单。
    4. remove(JMenu m):删除菜单条中的菜单m。

     


    2. 菜单
    由类JMenu创建的对象就是菜单。类JMenu的常用方法如下:

     

    1. JMenu():建立一个空标题的菜单。
    2. JMenu(String s):建立一个标题为s的菜单。
    3. add(JMenuItem item):向菜单增加由参数item指定的菜单选项。
    4. add(JMenu menu):向菜单增加由参数menu指定的菜单。实现在菜单嵌入子菜单。
    5. addSeparator():在菜单选项之间画一条分隔线。
    6. getItem(int n):得到指定索引处的菜单项。
    7. getItemCount():得到菜单项数目。
    8. insert(JMenuItem item,int n):在菜单的位置n插入菜单项item.
    9. remove(int n):删除菜单位置n的菜单项
    10. removeAll():删除菜单的所有菜单项。

    3.菜单项
    类JMenuItem 的实例就是菜单项。类JMenuItem的常用方法如下:

     

    1. JMenuItem():构造无标题的菜单项。
    2. JMenuItem(String s):构造有标题的菜单项。
    3. setEnabled(boolean b):设置当前单项是否可被选择。
    4. isEnabled():返回当前菜单项是否可被用户选择。
    5. getLabel():得到菜单项的名称。
    6. setLabel():设置菜单选项的名称。
    7. addActionListener(ActionListener e):为菜单项设置监视器。监视器接受点击某个菜单的动作事件。

    4. 处理菜单事件
    菜单的事件源是用鼠标点击某个菜单项。处理该事件的接口是ActionListener,要实现的接口方法是actionPerformed(ActionEvent e),获得事件源的方法getSource(). 

    【例 11-15】小应用程序示意窗口有菜单条的实现方法。设有一个按钮,当按钮处于打开窗口状态时,单击按钮将打开一个窗口,窗口设有一个菜单条,有两个菜单,每个菜单又各有三个菜单项。当一个菜单项被选中时,菜单项监视方法在文本框中显示相应菜单项被选中字样。

    5. 嵌入子菜单
    创建了一个菜单,并创建多个菜单项,其中某个菜单项又是一个(含其他菜单项的)菜单,这就构成菜单嵌套。例如,将上述程序中的有关代码改成如下:
        Menu menu1,menu2,item4;
        MenuItem item3,item5,item6,item41,item42;
    另插入以下代码创建item41和item42菜单项,并把它们加入到item4菜单中:
        item41= new MenuItem(“东方红”);
        item42 = new MenuItem(“牡丹”);
        item4.add(item41);
        item4.add(item42);
    则点击item4菜单时,又会打开两个菜单项供选择。

    6. 向菜单增加退出项
    增设一个新的菜单项,对该菜单项加入监视,对应的监视方法中使用System.exit()方法,就能实现单击该菜单项时退出Java运行环境。例如,以下示意代码:

    item7 = new MenuItem(“退出”);
    item7.addActionListener(this);

    public void actionPerformed(ActionEvent e){
        if(e.getSource()==item7){
            System.exit(0);
        }
    }

    7.设置菜单项的快捷键
    用MenuShortcut类为菜单项设置快捷键。构造方法是MenuShortcut(int key)。其中key可以取值KeyEvent.VK_A至KenEvent.VK_Z,也可以取 ‘a’到 ‘z’键码值。菜单项使用setShortcut(MenuShortcut k)方法来设置快捷键。例如,以下代码设置字母e为快捷键。
    class Herwindow extends Frame implements ActionListener{
        MenuBar menbar;
        Menu menu;
        MenuItem item;
        MenuShortcut shortcut = new MenuShortcut(KeyEvent.VK_E);
        …
        item.setShortcut(shortcut);
        …
    }

     

    选择框菜单项

     

    菜单也可以包含具有持久的选择状态的选项,这种特殊的菜单可由JCheckBoxMenuItem类来定义。JCheckBoxMenuItem对象像选择框一样,能表示一个选项被选中与否,也可以作为一个菜单项加到下拉菜单中。点击JCheckBoxMenuItem菜单时,就会在它的左边出现打勾符号或清除打勾符号。例如,在例6.5程序的类MenuWindow中,将代码
        addItem(menu1,“跑步”,this);addItem(menu1,”跳绳”,this);
    改写成以下代码,就将两个普通菜单项“跑步“和“跳绳”改成两个选择框菜单项:
        JCheckBoxMenuItem item1 = new JCheckBoxMenuItem(“跑步”);
        JCheckBoxMenuItem item2 = new JCheckBoxMenuItem(“跳绳”);
        item1.setActionCommand(“跑步”);
        item1.addActionListener(this);
        menu1.add(item1);
        item2.setActionCommand(“跳绳”);
        item2.addActionListener(this);
        menu1.add(item2);

     

    工具栏:

    工具栏中提供了快速执行常用命令的按钮,可以将它随意拖拽到窗体的四周,JToolBar 工具栏相当于一个组件的容器,可以添加按钮,微调控制器等组件到工具栏中。每个添加的组件会被分配一个整数的索引,来确定这个组件的显示顺序。另外,组件可以位于窗体的任何一个边框,也可以成为一个单独的窗体。

    注意:如果希望工具栏可以随意拖动,窗体一定要采用默认的边界布局方式,并且不能在边界布局的四周添加任何组件。

    工具栏默认是可以随意拖动的。

    常用构造方法
    JToolBar():建立一个新的JToolBar,位置为默认的水平方向.

    JToolBar(int orientation):建立一个指定的JToolBar.

    JToolBar(String name):建立一个指定名称的JToolBar.

    JToolBar(String name,int orientation):建立一个指定名称和位置的JToolBar.

    对话框:

      (1)对话框是一种大小不能变化、不能有菜单的容器窗口;

      (2)对话框不能作为一种应用程序的主框架,而必须包含在其他的容器当中;

      (3)Java提供多种形式的对话框;

      ——JOptionPane类:支持简单、标准的对话框;

      ——JFileChooser类:支持文件打开、保存对话框;

      ——ProgressMonitor类:支持操作进度条控制对话框等。

      (4)对话框依赖于框架,当框架撤销时,依赖该框架的对话框也会撤销,当框架窗口恢复时,依赖框架的对话框也会返回到屏幕;

      (5)对话框分为有模式和无模式两种:

        1)有模式的对话框处于激活状态时,程序只能响应对话框内部的事件,不能再激活它所依赖的窗口或组件,而且它将堵塞当前线程的执行,即堵塞使得对话框处于激活状态的线程,直到该对话框消失不可见;

        2)无模式对话框处于激活状态时,程序仍能激活它所依赖的窗口或者组件,它不能堵塞线程的执行。

    选项对话框:

      (1)JOptionPane提供的对话框是模式对话框,当模式对话框显示时,它不允许用户输入到程序的其他的窗口,使用JOptionPane,可以创建和对定义问题、信息、警告、和错误等几种类型的对话框。

      (2)创建对话框:

      对话框的构造方法:

      ——JDialog  (Frame  owner)   ——构造一个没有标题的非模式对话框

      ——JDialog(Frame  owner ,  boolean  modal)  ——构造一个没有标题的对话框,boolean 型参数modal指定对话框是否为模式窗口

      ——JDialog(Frame owner ,String  title)  ——构造一个有标题的非模式对话框

      ——JDialog(Frame  owner , String  title,  boolean  modal)  ——构造一个有标题的

    第二部分:实验部分

    实验1:测试程序1(7分)

    代码如下:

    package menu;
     
    import java.awt.*;
    import javax.swing.*;
     
    /**
     * @version 1.25 2018-04-10
     * @author Cay Horstmann
     */
    public class MenuTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             var frame = new MenuFrame();
             frame.setTitle("MenuTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    package menu;
     
    import java.awt.event.*;
    import javax.swing.*;
     
    /**
     * A frame with a sample menu bar.
     */
    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;
     
       /**
        *在显示台上显示已选择动作名称
        */
       class TestAction extends AbstractAction
       {
          public TestAction(String name)
          {
             super(name);
          }
     
          public void actionPerformed(ActionEvent event)
          {
             System.out.println(getValue(Action.NAME) + " selected.");//getValue返回被存储的值
          }
       }
     
       public MenuFrame()
       {
          setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
     
          var fileMenu = new JMenu("File");//菜单定义
           
          fileMenu.add(new TestAction("New"));
     
          // 加速器
     
          var openItem = fileMenu.add(new TestAction("Open"));
          openItem.setAccelerator(KeyStroke.getKeyStroke("ctrl O"));//"ctrl O"设置为Open菜单项的加速器
     
          fileMenu.addSeparator();//添加分隔符行
     
          saveAction = new TestAction("Save");
          JMenuItem saveItem = fileMenu.add(saveAction);
          saveItem.setAccelerator(KeyStroke.getKeyStroke("ctrl S"));//"ctrl S"设置为Save菜单项的加速器
     
          saveAsAction = new TestAction("Save As");
          fileMenu.add(saveAsAction);
           
          fileMenu.addSeparator();//添加分隔符行
     
          fileMenu.add(new AbstractAction("Exit")
             {
                public void actionPerformed(ActionEvent event)
                {
                   System.exit(0);
                }
             });
     
          //复选框和单按钮菜单项
     
          readonlyItem = new JCheckBoxMenuItem("Read-only");
          readonlyItem.addActionListener(new ActionListener()
             {
                public void actionPerformed(ActionEvent event)
                {
                   boolean saveOk = !readonlyItem.isSelected();
                   saveAction.setEnabled(saveOk);//若"Read-only"复选框未被选择,Save、Save as菜单项均可执行点击操作
                   saveAsAction.setEnabled(saveOk);
                }
             });
     
          var group = new ButtonGroup();
     
          var insertItem = new JRadioButtonMenuItem("Insert");
          insertItem.setSelected(true);//默认
          var overtypeItem = new JRadioButtonMenuItem("Overtype");
     
          group.add(insertItem);
          group.add(overtypeItem);
     
          // 展示图标
     
          var cutAction = new TestAction("Cut");
          cutAction.putValue(Action.SMALL_ICON, new ImageIcon("cut.gif"));//putValue将值放置在动作对象内
          var copyAction = new TestAction("Copy");
          copyAction.putValue(Action.SMALL_ICON, new ImageIcon("copy.gif"));
          var pasteAction = new TestAction("Paste");
          pasteAction.putValue(Action.SMALL_ICON, new ImageIcon("paste.gif"));
     
          var editMenu = new JMenu("Edit");//定义菜单
          editMenu.add(cutAction);
          editMenu.add(copyAction);
          editMenu.add(pasteAction);
     
          //展示子菜单
     
          var optionMenu = new JMenu("Options");
     
          optionMenu.add(readonlyItem);
          optionMenu.addSeparator();//分隔符
          optionMenu.add(insertItem);
          optionMenu.add(overtypeItem);
     
          editMenu.addSeparator();
           
          editMenu.add(optionMenu);
     
          //展示快捷键
     
          var helpMenu = new JMenu("Help");
          helpMenu.setMnemonic('H');//设置快捷字符,该字符在标签中以下划线的项式显示
     
          var indexItem = new JMenuItem("Index");
          indexItem.setMnemonic('I');
          helpMenu.add(indexItem);
     
          //在快捷键上添加动作
          var aboutAction = new TestAction("About");
          aboutAction.putValue(Action.MNEMONIC_KEY, new Integer('A'));
          helpMenu.add(aboutAction);
           
          // 将所有的顶部菜单添加到菜单栏上
     
          var menuBar = new JMenuBar();
          setJMenuBar(menuBar);//设置菜单栏
     
          menuBar.add(fileMenu);
          menuBar.add(editMenu);
          menuBar.add(helpMenu);
     
          // 展示弹出菜单
     
          popup = new JPopupMenu();
          popup.add(cutAction);
          popup.add(copyAction);
          popup.add(pasteAction);
     
          var panel = new JPanel();
          panel.setComponentPopupMenu(popup);//设置组件的弹出菜单
          add(panel);
       }
    }
    运行截图:

    实验1:测试程序2(7分)

    package toolBar;
     
    import java.awt.*;
    import javax.swing.*;
     
    /**
     * @version 1.15 2018-04-10
     * @author Cay Horstmann
     */
    public class ToolBarTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             var frame = new ToolBarFrame();
             frame.setTitle("ToolBarTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    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
    {
       private static final int DEFAULT_WIDTH = 300;
       private static final int DEFAULT_HEIGHT = 200;
       private JPanel panel;
     
       public ToolBarFrame()
       {
          setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
     
          // add a panel for color change
     
          panel = new JPanel();
          add(panel, BorderLayout.CENTER);
     
          // 设置动作
     
          var blueAction = new ColorAction("Blue", new ImageIcon("blue-ball.gif"), Color.BLUE);
          var yellowAction = new ColorAction("Yellow", new ImageIcon("yellow-ball.gif"),
                Color.YELLOW);
          var redAction = new ColorAction("Red", new ImageIcon("red-ball.gif"), Color.RED);
     
          var exitAction = new AbstractAction("Exit", new ImageIcon("exit.gif"))
             {
                public void actionPerformed(ActionEvent event)
                {
                   System.exit(0);
                }
             };
          exitAction.putValue(Action.SHORT_DESCRIPTION, "Exit");
     
          // populate toolbar
     
          var bar = new JToolBar();//创建工具栏
          bar.add(blueAction);//用action对象填充工具栏
          bar.add(yellowAction);
          bar.add(redAction);
          bar.addSeparator();
          bar.add(exitAction);
          add(bar, BorderLayout.NORTH);
     
          // populate menu
     
          var menu = new JMenu("Color");//菜单
          menu.add(yellowAction);
          menu.add(blueAction);
          menu.add(redAction);
          menu.add(exitAction);
          var menuBar = new JMenuBar();//菜单栏
          menuBar.add(menu);
          setJMenuBar(menuBar);//设置菜单栏
       }
     
       /**
        * 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);
             putValue(Action.SMALL_ICON, icon);
             putValue(Action.SHORT_DESCRIPTION, name + " background");
             putValue("Color", c);
          }
     
          public void actionPerformed(ActionEvent event)
          {
             Color c = (Color) getValue("Color");
             panel.setBackground(c);
          }
       }
    }
    运行截图:

    实验1:测试程序3(7分)

    package optionDialog;
     
    import java.awt.*;
    import javax.swing.*;
     
    /**
     * @version 1.35 2018-04-10
     * @author Cay Horstmann
     */
    public class OptionDialogTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             var frame = new OptionDialogFrame();
             frame.setTitle("OptionDialogTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    package optionDialog;
     
    import javax.swing.*;
     
    /**
     * A panel with radio buttons inside a titled border.
     */
    public class ButtonPanel extends JPanel
    {
       private ButtonGroup group;
     
       /**
        * Constructs a button panel.
        * @param title the title shown in the border
        * @param options an array of radio button labels
        */
       public ButtonPanel(String title, String... options)
       {
          setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(), title));//设置边框即标题
          setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));//垂直排列
          group = new ButtonGroup();
     
          // 为每一个选项创建一个单选钮
          for (String option : options)
          {
             var button = new JRadioButton(option);
             button.setActionCommand(option);
             add(button);
             group.add(button);
             button.setSelected(option == options[0]);//设置默认选择
          }
       }
     
       /**
        * Gets the currently selected option.
        * @return the label of the currently selected radio button.
        */
       public String getSelection()
       {
          return group.getSelection().getActionCommand();
       }
    }
    复制代码
     
    复制代码
    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
    {
       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()
       {
          var 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);
     
          // Show按钮的添加
     
          var showPanel = new JPanel();
          var showButton = new JButton("Show");
          showButton.addActionListener(new ShowAction());
          showPanel.add(showButton);
     
          add(gridPanel, BorderLayout.CENTER);
          add(showPanel, BorderLayout.SOUTH);
          pack();
       }
     
       /**
        *得到当前选择的信息
        * @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);//JOptionPane.xxx来获得这个静态字段的值
          }
          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)
       {
          var g2 = (Graphics2D) g;
          var 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);
       }
    }

    运行结果:

     

    实验1:测试程序4(7分)

    package dialog;
    
    import java.awt.*;
    import javax.swing.*;
    
    /**
     * @version 1.35 2018-04-10
     * @author Cay Horstmann
     */
    public class DialogTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
              DialogFrame frame = new DialogFrame();
             frame.setTitle("DialogTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    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);//调用超类的构造器
    
          // add HTML label to center
    
          add(
             new JLabel(
                "<html><h1><i>Core Java</i></h1><hr>By Cay Horstmann</html>"),
             BorderLayout.CENTER);
    
          // OK button closes the dialog
    
          JButton ok = new JButton("OK");
          ok.addActionListener(event -> setVisible(false));//可见
    
          // add OK button to southern border
    
           JPanel panel = new JPanel();
          panel.add(ok);
          add(panel, BorderLayout.SOUTH);
    
          pack();
       }
    }
    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();//菜单栏
          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));//退出
          fileMenu.add(exitItem);
       }
    }
    运行结果:

    实验1:测试程序5(7分)

    package dataExchange;
     
    import java.awt.*;
    import javax.swing.*;
     
    /**
     * @version 1.35 2018-04-10
     * @author Cay Horstmann
     */
    public class DataExchangeTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             var 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()
       {
          // 创建File菜单
     
          var mbar = new JMenuBar();//菜单栏
          setJMenuBar(mbar);
          var fileMenu = new JMenu("File");//菜单
          mbar.add(fileMenu);
     
          //添加Connect、Exit菜单项
     
          var connectItem = new JMenuItem("Connect");//菜单项
          connectItem.addActionListener(new ConnectAction());
          fileMenu.add(connectItem);
     
          //关闭程序
     
          var exitItem = new JMenuItem("Exit");
          exitItem.addActionListener(event -> System.exit(0));
          fileMenu.add(exitItem);
     
          textArea = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);//含滚动条的文本区
          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)
          {
             //第一次,创建对话框
     
             if (dialog == null) dialog = new PasswordChooser();
     
             //设置默认值
             dialog.setUser(new User("yourname", null));
     
             //弹出对话框
             if (dialog.showDialog(DataExchangeFrame.this, "Connect"))
             {
                // 重新得到用户输入
                User u = dialog.getUser();
                textArea.append("user name = " + u.getName() + ", password = "
                   + (new String(u.getPassword())) + "
    ");
             }
          }
       }
    }
    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());
     
          //创建还有user name与password域的面板
     
          var 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);//点击OK按钮后关闭对话框
          });
     
          var cancelButton = new JButton("Cancel");
          cancelButton.addActionListener(event -> dialog.setVisible(false));
     
          //添加按钮
     
          var 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)//放置默认值
       {
          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;
     
          //拥有者框架
     
          Frame owner = null;
          if (parent instanceof Frame)
             owner = (Frame) parent;
          else
             owner = (Frame) SwingUtilities.getAncestorOfClass(Frame.class, parent);//返回给定组件的最先的父容器
     
          //第一次或改变拥有者,则创建新的对话框 
     
          if (dialog == null || dialog.getOwner() != owner)
          {
             dialog = new JDialog(owner, true);
             dialog.add(this);
             dialog.getRootPane().setDefaultButton(okButton);//设置默认按钮
             dialog.pack();
          }
     
          //设置标题并展示对话框
     
          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;
       }
    }
    运行结果:



    实验1:测试程序6(7分)

    package fileChooser;
     
    import java.awt.*;
    import javax.swing.*;
     
    /**
     * @version 1.26 2018-04-10
     * @author Cay Horstmann
     */
    public class FileChooserTest
    {
       public static void main(String[] args)
       {
          EventQueue.invokeLater(() -> {
             var frame = new ImageViewerFrame();
             frame.setTitle("FileChooserTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    package fileChooser;
     
    import java.io.*;
     
    import javax.swing.*;
    import javax.swing.filechooser.*;
    import javax.swing.filechooser.FileFilter;
     
    /**
     * A frame that has a menu for loading an image and a display area for the
     * loaded image.
     */
    public class ImageViewerFrame extends JFrame
    {
       private static final int DEFAULT_WIDTH = 300;
       private static final int DEFAULT_HEIGHT = 400;
       private JLabel label;
       private JFileChooser chooser;
     
       public ImageViewerFrame()
       {
          setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
     
          // set up menu bar
          var menuBar = new JMenuBar();//菜单栏
          setJMenuBar(menuBar);
     
          var menu = new JMenu("File");//菜单
          menuBar.add(menu);
     
          var openItem = new JMenuItem("Open");
          menu.add(openItem);
          openItem.addActionListener(event -> {
             chooser.setCurrentDirectory(new File("."));//设置当前目录
     
             //文件选择对话框
                int result = chooser.showOpenDialog(ImageViewerFrame.this);
     
                // 图像文件接受,把它作为标签的图标
                if (result == JFileChooser.APPROVE_OPTION)
                {
                   String name = chooser.getSelectedFile().getPath();//获取用户选择的一个文件路径
                   label.setIcon(new ImageIcon(name));
                   pack();
                }
             });
     
          var exitItem = new JMenuItem("Exit");
          menu.add(exitItem);
          exitItem.addActionListener(event -> System.exit(0));
     
          //使用标签显示图像
          label = new JLabel();
          add(label);
     
          // 创建文件选择器
          chooser = new JFileChooser();
     
          //接受所有以.jpg, .jpeg, .gif格式的图片文件
          var filter = new FileNameExtensionFilter(
                "Image files", "jpg", "jpeg", "gif");
          chooser.setFileFilter(filter);//文件对话框的文件过滤器
     
          chooser.setAccessory(new ImagePreviewer(chooser));//设置附件组件
     
          chooser.setFileView(new FileIconView(filter, new ImageIcon("palette.gif")));//设置文件视图来提供文件过滤器显示信息
       }
    }
    package fileChooser;
     
    import java.awt.*;
    import java.io.*;
     
    import javax.swing.*;
     
    /**
     * A file chooser accessory that previews images.
     */
    public class ImagePreviewer extends JLabel
    {
       /**
        * Constructs an ImagePreviewer.
        * @param chooser the file chooser whose property changes trigger an image
        *        change in this previewer
        */
       public ImagePreviewer(JFileChooser chooser)
       {
          setPreferredSize(new Dimension(100, 100));
          setBorder(BorderFactory.createEtchedBorder());//3D效果的直线边框
     
          chooser.addPropertyChangeListener(event -> {
             if (event.getPropertyName() == JFileChooser.SELECTED_FILE_CHANGED_PROPERTY)
             {
                //用户选定新的文件
                File f = (File) event.getNewValue();
                if (f == null)
                {
                   setIcon(null);
                   return;
                }
     
                //将图像设置未图标
                var icon = new ImageIcon(f.getPath());
     
                //图标过大或过小,缩放
                if (icon.getIconWidth() > getWidth())
                   icon = new ImageIcon(icon.getImage().getScaledInstance(
                         getWidth(), -1, Image.SCALE_DEFAULT));
     
                setIcon(icon);//设置图标
             }
          });
       }
    }
    package fileChooser;
     
    import java.io.*;
    import javax.swing.*;
    import javax.swing.filechooser.*;
    import javax.swing.filechooser.FileFilter;
     
    /**
     * A file view that displays an icon for all files that match a file filter.
     */
    public class FileIconView extends FileView
    {
       private FileFilter filter;
       private Icon icon;
     
       /**
        * Constructs a FileIconView.
        * @param aFilter a file filter--all files that this filter accepts will be shown 
        * with the icon.
        * @param anIcon--the icon shown with all accepted files.
        */
       public FileIconView(FileFilter aFilter, Icon anIcon)
       {
          filter = aFilter;
          icon = anIcon;
       }
     
       public Icon getIcon(File f)
       {
          if (!f.isDirectory() && filter.accept(f)) return icon;
          else return null;
       }
    }
    运行截图:

    实验1:测试程序7(7分)

    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();
             frame.setTitle("ColorChooserTest");
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
          });
       }
    }
    package colorChooser;
     
    import javax.swing.*;
     
    /**
     * A frame with a color chooser panel
     */
    public class ColorChooserFrame extends JFrame
    {
       private static final int DEFAULT_WIDTH = 300;
       private static final int DEFAULT_HEIGHT = 200;
     
       public ColorChooserFrame()
       {      
          setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
     
          // add color chooser panel to frame
     
          ColorChooserPanel panel = new ColorChooserPanel();//初始颜色为白色的颜色选择器
          add(panel);
       }
    }
    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()
       {
          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);
       }
     
       /**
        *弹出模式颜色选择器
        */
       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);//将当前选中的颜色,点击OK按钮,设置为背景颜色
          }
       }
     
       /**
        * 弹出无模式颜色选择器,点击OK,对话框的背景颜色就会被设置为所选择的颜色
        */
       private class ModelessListener implements ActionListener
       {
          private JDialog dialog;
          private JColorChooser chooser;
     
          public ModelessListener()
          {
             chooser = new JColorChooser();//颜色选择器
             dialog = JColorChooser.createDialog(ColorChooserPanel.this, "Background Color",
                   false /* not modal */, chooser, 
                   event -> setBackground(chooser.getColor()), 
                   null /* no Cancel button listener */);
          }//点击OK,对话框的背景颜色就会被设置为所选择的颜色
     
          public void actionPerformed(ActionEvent event)
          {
             chooser.setColor(getBackground());
             dialog.setVisible(true);
          }
       }
     
       /**
        * 弹出无模式颜色选择器,当用户选择一种新的颜色,立即改变背景颜色 
        */
       private class ImmediateListener implements ActionListener
       {
          private JDialog dialog;
          private JColorChooser chooser;
     
          public ImmediateListener()
          {
             chooser = new JColorChooser();
             chooser.getSelectionModel().addChangeListener(
                   event -> setBackground(chooser.getColor()));//监视颜色选择,立即反馈给用户
     
             dialog = new JDialog((Frame) null, false /* not modal */);//无模式对话框
             dialog.add(chooser);
             dialog.pack();
          }
     
          public void actionPerformed(ActionEvent event)
          {
             chooser.setColor(getBackground());
             dialog.setVisible(true);
          }
       }
    }
    运行结果:

    实验2:结对编程练习包含以下4部分:(该项作业16周实验课现场检查,并单独评分)

    1)   程序设计思路简述;

    2)   符合编程规范的程序代码;

    3)   程序运行功能界面截图;

    实验总结:(16分)

    在本周的实验中,通过阅读完整的代码,我逐渐了解了菜单的完整使用过程及方法,对菜单有了更深的理解。在老师讲解知识后,要把不明白的程序要弄清楚,多多理解几次。本次的结对编程让我体会到结对编程的好处,两个人同时去这同一个程序,可以通过讨论,相互提出问题,解决问题,可达到事半功倍的效果。也是对编程能力的一种提升。这次结对编程内容同时也是对这次新知识的一种应用,实现了对新知识的巩固,利用。以后要多通过自己实践,去应用理论知识。

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  • 原文地址:https://www.cnblogs.com/2360689227t/p/12013694.html
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