201871010135 张玉晶《面向对象程序设计（java）》第十五周学习总结

                                   

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/12000169.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。

 

第一部分：总结菜单、对话框两类组件用途及常用API

     一. 菜单

          1. 菜单是GUI编程中经常用到的一种组件。  位于窗口顶部的菜单栏中包括下拉菜单的名字。 点击一个名字就可以打开包含菜单项和子菜单的菜单。

           2. 创建一个菜单栏：菜单栏是一个可以添加到容器组件的任何位置的组件。 通常放置在框架的顶部。

                                            JMenuBar menuBar=new JMenuBar();

          3. 调用框架的setJMenuBar 方法可将一个菜单栏对象添加到框架上。   frame.serJMenuBar(menuBar);

          4.  创建菜单对象，并将菜单对象添加到菜单栏中

               JMenu editMenu = new JMenu("Edit");

               menuBar.add(editMenu);

          5. 向菜单对象添加一个菜单项

              JMenuItem pasteitem = new JMenuItem();

              editMenu.add(pasteitem);

          6. 向菜单添加分隔符行

             editMenu.addSeperator();

          7. 向菜单对象项添加子菜单

              JMenu optionsMenu = new Jmenu("option");

              editMenu.add(optionsMenu);

          8.  当用户选择菜单时，将触发一个动作事件。 这里需要为每一个菜单项安装一个动作监听器。

              ActionListener listener=...;

              pasteitem.addActionListener(listener);

          9. 菜单对象的add方法可返回创建的子菜单项。 可以使用以下方法来获取他，并添加监听器：

              JMenuItem pasteitem = editMenu.add("Paste");

              pasteitem.addActionListener(listener);

         二.  弹出菜单（JPopupMenu)

              1. 弹出菜单是不固定在菜单栏中随处浮动的菜单 

                     

               2. 创建一个弹出菜单与创建一个常规菜单的方法类似，但是弹出菜单没有标题：

                   JPopupMenu  popup = new JPopupMenu();

              3. 然后用常规方法为弹出菜单添加菜单项：

                 JMenuItem item = new JMenuItem("Cut");

                  item.addActionListener(listener);

                  popup.add(item);

               4. 弹出菜单调用show方法才能显示出来：

                   popup.show(panel,x,y);

                5. 弹出式触发器（pop-up trigger): • 用户点击鼠标某个键时弹出菜单

                                                                       • 在Windows或者Linux中，弹出式触发器是鼠标右键

                                                                       • 要想在用户点击某一个组件的时候弹出菜单，该组件就要调用以下方法设置弹出式触发器：    component.setComponentPopupMenu(popup);

       三.  快捷键

              1. 可以为菜单项设置快捷键，在当前菜单打开的情况下，可按下某菜单的快捷键，相当于鼠标点击了该菜单项。

                    JMenuItem CutItem = new JMenuItem("Index");

                    CutItem.setMnemonic("I");

                  此快捷键就会自动显示在菜单项中，快捷键下面有一条下划线。

                    

        四. 加速器

              1. 加速器可以在不打开菜单的情况下选中菜单项的快捷键，例如： CTRL+S关联到Save

              2. 使用SetAccelerator方法可以将加速器关联到一个菜单项，该方法使用KeyStroke类型的对象做为参数

                      openitem.setAccelerator(KeyStroke.getKeyStroke("ctrl o"));

              3. 加速器只关联在菜单项，而不能关联菜单。

              4. 加速器实际上并不打开菜单，而是直接激活菜单关联的动作事件。

          五. 启用和禁用菜单项

               1. 屏蔽 / 启用菜单项的方法： aMenuItem.setEnabled(boolean)

                2. 如果需要动态启用/ 屏蔽某菜单项，则需要为菜单项注册 "menuSelected" 事件监听器。javax.swing.event包定义了MenuListener接口它有三个方法

                      • void menuSelected(MenuEvent event)

                      •  void menuDeselected(MenuEvent event)

                      • void menuCanceled(MenuEvent event)

           五. 工具栏（JToolBar)

                 1. 调用setToolTest方法添加工具提示到  JComponent:  exitButton.setToolTipText("Exit");

                 2. 如果使用Action对象  就可以用SHORT-DESCRIPTION关联工具提示：

                      exitButton.putValue(Action.SHORT-DESCRIPTION, "Exit");       

           六. 对话框

                1. 它是一种大小不能变化，不能有菜单的容器窗口。

                2. 对话框依赖于框架。当框架被清除时，对话框也会被清除。对话框在显示时，如果框架被最小化，对话框也将变为不可见。

                3. 构造一个标题为" Dialog" 的模式对话框，该对话框为框架 frame所拥有      JDialog dialog = new JDialog(frame, "Dialog", true)

                4. 选择对话框 （JOption Pane）

                     定义多个showXxxDialog形式的静态方法

                       • showMessageDialog--------信息对话框，显示信息，告知用户发生了什么

                       • showConfirmDialog ---------确认对话框，显示问题，要求用户进行确认

                       • showOptionDialog  ----------选择对话框，显示选项，要求用户进行选择

                       • showInputDialog ------------输入对话框，提示用户进行输入

                 5. 创建对话框

                     • JDialog (Frame owner)  ---------构造一个没有标提的非模式对话框

                     • JDialog (Frame owner, boolean modal) ------构造一个没有标题对话框，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) -----构造一个有标题的对话框

               6. showXxxDialog 方法的参数

                     •  Component parentComponent     对话框的父窗口对象，其屏幕坐标将决定对话框的显示位置，此参数也可以为null， 表示采用缺省的Frame作为父窗口，此时对话框将设置在屏幕的正中

                     • Object message   显示对话框中的描述信息。 该参数是一个string对象，但也可以是一个图标，一个组件或者一个对象数组

                     

2、实验内容和步骤

实验1：

测试程序1：

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。

 

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;

   /**
    * A sample action that prints the action name to System.out.
    */
   class TestAction extends AbstractAction
   {
      public TestAction(String name)
      {
         super(name);
      }

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

   public MenuFrame()
   {
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);//设置菜单框架的大小

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

      // 演示加速器

      JMenuItem openItem = fileMenu.add(new TestAction("Open"));  //
      openItem.setAccelerator(KeyStroke.getKeyStroke("ctrl O"));  //将加速器ctrl O关联到openItem菜单项

      fileMenu.addSeparator();  //在fileMenu菜单中添加分隔符

      saveAction = new TestAction("Save");
      JMenuItem saveItem = fileMenu.add(saveAction);
      saveItem.setAccelerator(KeyStroke.getKeyStroke("ctrl S"));   //将加速器ctrl S关联到saveItem菜单项

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

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

      // 演示复选框和单选按钮菜单

      readonlyItem = new JCheckBoxMenuItem("Read-only");  //用Read-only构造一个复选框菜单项
      readonlyItem.addActionListener(new ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               boolean saveOk = !readonlyItem.isSelected();  //获取菜单项的选择状态
               saveAction.setEnabled(saveOk);  //启用菜单项
               saveAsAction.setEnabled(saveOk);
            }
         });

      ButtonGroup group = new ButtonGroup();  //为单选钮组构造一个对象

      JRadioButtonMenuItem insertItem = new JRadioButtonMenuItem("Insert");//创建一个单选按钮
      insertItem.setSelected(true); //设置这个菜单的选择状态
      JRadioButtonMenuItem overtypeItem = new JRadioButtonMenuItem("Overtype");  

      group.add(insertItem);//把insertItem对象加到按钮组中
      group.add(overtypeItem);

      // 演示图标 

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

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

      // 演示嵌套菜单

      JMenu optionMenu = new JMenu("Options");

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

      editMenu.addSeparator();
      editMenu.add(optionMenu);//把optionMenu菜单嵌套在edit菜单中

      // 演示助记符

      JMenu helpMenu = new JMenu("Help");
      helpMenu.setMnemonic('H');  //为Help这个菜单设置快捷键H

      JMenuItem indexItem = new JMenuItem("Index");
      indexItem.setMnemonic('I');  //为Help这个菜单设置快捷键I
      helpMenu.add(indexItem);//将Index菜单项添加到Help这个菜单中

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

      JMenuBar menuBar = new JMenuBar();//创建一个菜单栏
      setJMenuBar(menuBar);

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

      // 演示弹出窗口

      popup = new JPopupMenu();  //创建一个弹出菜单
      popup.add(cutAction);
      popup.add(copyAction);
      popup.add(pasteAction);

      JPanel panel = new JPanel();
      panel.setComponentPopupMenu(popup);  //用户点击panel时弹出菜单
      add(panel);
   }
}

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(() -> {
         MenuFrame frame = new MenuFrame();
         frame.setTitle("MenuTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

运行结果如下：

               

       

  

测试程序2：

掌握工具栏和工具提示的用法

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

/**
 * 带有工具栏和颜色变化菜单的框架
 */
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);

      // 添加用于颜色更改的面板

      panel = new JPanel();
      add(panel, BorderLayout.CENTER);//将这个面板加在边框的中间

      // 设置操作

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

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

      // 填充工具栏

      JToolBar bar = new JToolBar();  //创建一个工具栏
      bar.add(blueAction); 
      bar.add(yellowAction);
      bar.add(redAction);
      bar.addSeparator();  //给工具栏添加分隔符
      bar.add(exitAction);
      add(bar, BorderLayout.NORTH);

      //填充菜单

      JMenu menu = new JMenu("Color");
      menu.add(yellowAction);
      menu.add(blueAction);
      menu.add(redAction);
      menu.add(exitAction);
      JMenuBar menuBar = new JMenuBar();//创建菜单栏
      menuBar.add(menu);//将菜单栏加到菜单上
      setJMenuBar(menuBar);
   }

   /**
    * 颜色动作将框架的背景设置为给定的颜色.
    */
   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);  //给面板加背景
      }
   }
}

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(() -> {
         ToolBarFrame frame = new ToolBarFrame();
         frame.setTitle("ToolBarTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

运行结果如下：

         

测试程序3：

掌握选项对话框的用法

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.awt.geom.Rectangle2D.Double;
import java.util.*;
import javax.swing.*;
/**
 * 包含用于选择各种选项对话框的设置的框架。
 */
public class OptionDialogFrame extends JFrame
{
   private ButtonPanel typePanel;
   private ButtonPanel messagePanel;
   private ButtonPanel messageTypePanel;
   private ButtonPanel optionTypePanel;
   private ButtonPanel optionsPanel;
   private ButtonPanel inputPanel;
   private String messageString = "Message";
   private Icon messageIcon = new ImageIcon("blue-ball.gif");
   private Object messageObject = new Date();
   private Component messageComponent = new SampleComponent();

   public OptionDialogFrame()
   {
      JPanel gridPanel = new JPanel();
      gridPanel.setLayout(new GridLayout(2, 3));//设置该面板的布局管理器为2行3列的网格

      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);

      // 添加带有显示按钮的面板

      JPanel showPanel = new JPanel();
      JButton showButton = new JButton("Show");
      showButton.addActionListener(new ShowAction());
      showPanel.add(showButton);//把按钮添加到面板上

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

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

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

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

   /**
    * The action listener for the Show button shows a Confirm, Input, Message, or Option dialog
    * depending on the Type panel selection.
    */
   private class ShowAction implements ActionListener
   {
      public void actionPerformed(ActionEvent event)
      {
         if (typePanel.getSelection().equals("Confirm")) JOptionPane.showConfirmDialog( //显示确认对话框
               OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel),
               getType(messageTypePanel));
         else if (typePanel.getSelection().equals("Input"))
         {
            if (inputPanel.getSelection().equals("Text field")) JOptionPane.showInputDialog(//显示输入对话框
                  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(//显示信息对话框
               OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel));
         else if (typePanel.getSelection().equals("Option")) JOptionPane.showOptionDialog(//显示选择对话框
               OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel),
               getType(messageTypePanel), null, getOptions(), getOptions()[0]);
      }
   }
}

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

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

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

import javax.swing.*;

/**
 * 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));//创建一个带标题的边框
      setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
      group = new ButtonGroup();

      // 为每个选项制作一个单选按钮
      for (String option : options)
      {
         JRadioButton button = new JRadioButton(option);
         button.setActionCommand(option);
         add(button);
         group.add(button);
         button.setSelected(option == options[0]);
      }
   }

   /**
    * Gets the currently selected option.
    * @return the label of the currently selected radio button.
    */
   public String getSelection()
   {
      return group.getSelection().getActionCommand();
   }
}

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(() -> {
         OptionDialogFrame frame = new OptionDialogFrame();
         frame.setTitle("OptionDialogTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

运行结果如下：

            

        

测试程序4：

掌握对话框的创建方法

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);

      // 构造文件菜单

      JMenuBar menuBar = new JMenuBar();//创建一个菜单栏
      setJMenuBar(menuBar);
      JMenu fileMenu = new JMenu("File");
      menuBar.add(fileMenu);//将File菜单添加到菜单栏上

      // 添加和退出菜单项

      // About项目显示About对话框

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

      // 退出项目退出程序

      JMenuItem exitItem = new JMenuItem("Exit");
      exitItem.addActionListener(event -> System.exit(0));
      fileMenu.add(exitItem);//将菜单项添加到菜单上
   }
}

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);
      });
   }
}

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);

      //将html标签添加到中心

      add(
         new JLabel(
            "<html><h1><i>Core Java</i></h1><hr>By Cay Horstmann</html>"),
         BorderLayout.CENTER);

      // ok按钮关闭对话框

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

      // 将“ok”按钮添加到南部边框

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

运行结果如下：

     

测试程序5：

 掌握对话框的数据交换用法;

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()
   {
      // 构建文件菜单

      JMenuBar mbar = new JMenuBar();//创建一个菜单栏
      setJMenuBar(mbar);
      JMenu fileMenu = new JMenu("File");  //创建一个菜单
      mbar.add(fileMenu);//在菜单栏中添加菜单

      // 添加连接和退出菜单项

      JMenuItem connectItem = new JMenuItem("Connect");//创建一个菜单项
      connectItem.addActionListener(new ConnectAction());
      fileMenu.add(connectItem);//将菜单项添加到菜单

      // Exit项目退出程序

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

      textArea = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);
      add(new JScrollPane(textArea), BorderLayout.CENTER);//为文本区添加滚动条并放在边框的中间
      pack();
   }

   /**
    * The Connect action pops up the password dialog.
    */
   private class ConnectAction implements ActionListener
   {
      public void actionPerformed(ActionEvent event)
      {
         // 如果第一次构建对话框

         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"))
         {
            // 如果接受，检索用户输入
            User u = dialog.getUser();
            textArea.append("user name = " + u.getName() + ", password = "
               + (new String(u.getPassword())) + "
");
         }
      }
   }
}

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(() -> {
         DataExchangeFrame frame = new DataExchangeFrame();
         frame.setTitle("DataExchangeTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

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());

      // 构建一个包含用户名和密码字段的面板

      JPanel panel = new JPanel();
      panel.setLayout(new GridLayout(2, 2));//设置面板的布局管理器为2*2的网格
      panel.add(new JLabel("User name:"));
      panel.add(username = new JTextField(""));//给面板添加文本域
      panel.add(new JLabel("Password:"));
      panel.add(password = new JPasswordField(""));
      add(panel, BorderLayout.CENTER);//将该面板添加到边框的中间

      // 创建终止对话框的“确定”和“取消”按钮

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

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

      // 向南部边框添加按钮

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

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

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

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

      // 定位到owner 框架

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

      //如果是第一次，或者owner已经更改，请创建新对话框

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

      // 设置标题和显示对话框

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

/**
 * 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;
   }
}

运行结果如下：

          

测试程序6：

掌握文件对话框的用法

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);

      // 设置菜单栏
      JMenuBar menuBar = new JMenuBar();
      setJMenuBar(menuBar);

      JMenu menu = new JMenu("File");
      menuBar.add(menu);

      JMenuItem openItem = new JMenuItem("Open");
      menu.add(openItem);
      openItem.addActionListener(event -> {
         chooser.setCurrentDirectory(new File("."));

         // 显示文件选择器对话框
            int result = chooser.showOpenDialog(ImageViewerFrame.this);

            // 如果图像文件被接受，将其设置为标签的图标
            if (result == JFileChooser.APPROVE_OPTION)
            {
               String name = chooser.getSelectedFile().getPath();
               label.setIcon(new ImageIcon(name));
               pack();
            }
         });

      JMenuItem 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);

      // 设置文件选择器
      chooser = new JFileChooser();

      // 接受所有以jpg,jpeg ,gif结尾的图像文件
      FileNameExtensionFilter filter = new FileNameExtensionFilter(
            "Image files", "jpg", "jpeg", "gif");
      chooser.setFileFilter(filter);

      chooser.setAccessory(new ImagePreviewer(chooser));

      chooser.setFileView(new FileIconView(filter, new ImageIcon("palette.gif")));
   }
}

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());

      chooser.addPropertyChangeListener(event -> {
         if (event.getPropertyName() == JFileChooser.SELECTED_FILE_CHANGED_PROPERTY)
         {
            // 用户选择了一个新文件
            File f = (File) event.getNewValue();
            if (f == null)
            {
               setIcon(null);
               return;
            }

            // 将图像读入图标
            ImageIcon icon = new ImageIcon(f.getPath());

            // 如果图标太大，缩放它
            if (icon.getIconWidth() > getWidth())
               icon = new ImageIcon(icon.getImage().getScaledInstance(
                     getWidth(), -1, Image.SCALE_DEFAULT));

            setIcon(icon);
         }
      });
   }
}

import java.io.*;
import javax.swing.*;
import javax.swing.filechooser.*;
import javax.swing.filechooser.FileFilter;

/**
 *显示与文件过滤器匹配的所有文件的图标的文件视图。
 */
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;
   }
}

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(() -> {
         ImageViewerFrame frame = new ImageViewerFrame();
         frame.setTitle("FileChooserTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

运行结果如下：

              

测试程序7：

了解颜色选择器的用法

package 第十五周;
import javax.swing.*;

/**
 * A frame with a color chooser panel
 */
public class ColorChooserFrame extends JFrame
{
   private static final int DEFAULT_WIDTH = 300;    //两个私有属性，常量
   private static final int DEFAULT_HEIGHT = 200;
 
   public ColorChooserFrame()    //ColorChooserFrame构造器
   {     
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); //设置为两个常量大小的框架
 
      // add color chooser panel to frame
 
      ColorChooserPanel panel = new ColorChooserPanel();  //创建一个ColorChooserPanel类对象panel
      add(panel); //将panel添加到框架里面
   }
}

package 第十五周;
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()      //ColorChooserPanel构造器
   {
      JButton modalButton = new JButton("Modal");     //创建一个JButton按钮对象
      modalButton.addActionListener(new ModalListener());    //动作监听器对象
      add(modalButton);    //将JButton对象添加到框架里面
 
      JButton modelessButton = new JButton("Modeless");     //新建一个Modeless按钮
      modelessButton.addActionListener(new ModelessListener());   //添加动作监听器
      add(modelessButton);   //将按钮添加到框架当中
 
      JButton immediateButton = new JButton("Immediate");  //新建一个Immediate按钮
      immediateButton.addActionListener(new ImmediateListener());  //添加动作监听器
      add(immediateButton);  //将immediateButton添加到框架当中
   }
 
   /**
    * This listener pops up a modal color chooser
    */
   private class ModalListener implements ActionListener   //创建一个实现ActionListener接口的类ModalListener
   {
      public void actionPerformed(ActionEvent event)    //actionPerformed方法
      {
         Color defaultColor = getBackground();    //创建一个颜色类对象，设置为背景颜色
         Color selected = JColorChooser.showDialog(ColorChooserPanel.this, "Set background",
               defaultColor);
         if (selected != null) setBackground(selected);
      }
   }
 
   /**
    * This listener pops up a modeless color chooser. The panel color is changed when the user
    * clicks the OK button.
    */
   private class ModelessListener implements ActionListener  //ModelessListener类实现了ActionListener接口
   {
      private JDialog dialog;    //对话框
      private JColorChooser chooser;     //颜色选择器
 
      public ModelessListener()      //ModelessListener构造器
      {
         chooser = new JColorChooser();   //创建一个JColorChooser选择器类对象
         dialog = JColorChooser.createDialog(ColorChooserPanel.this, "Background Color",
               false /* not modal */, chooser,
               event -> setBackground(chooser.getColor()),
               null /* no Cancel button listener */);
      }//创建一个对话框，颜色选择器面板ColorChooserPanel.this是本类，提供组件。设置背景颜色为颜色选择器调用getColor方法得到的颜色
 
      public void actionPerformed(ActionEvent event)  //actionPerformed方法
      {
         chooser.setColor(getBackground());   //设置背景颜色
         dialog.setVisible(true);    //设置对话框组件可见
      }
   }
 
   /**
    * This listener pops up a modeless color chooser. The panel color is changed immediately when
    * the user picks a new color.
    */
   private class ImmediateListener implements ActionListener    //ImmediateListener是实现ActionListener接口的类
   {
      private JDialog dialog;
      private JColorChooser chooser;   //私有属性，颜色选择器的定义
 
      public ImmediateListener()   //ImmediateListener构造器
      {
         chooser = new JColorChooser();    //新建一个颜色选择器类对象
         chooser.getSelectionModel().addChangeListener(
               event -> setBackground(chooser.getColor()));
 
         dialog = new JDialog((Frame) null, false /* not modal */);
         dialog.add(chooser);//添加chooser到文本框当中
         dialog.pack();   //获取对话框的首选大小
      }
 
      public void actionPerformed(ActionEvent event)//actionPerformed方法
      {
         chooser.setColor(getBackground());    //设置背景颜色
         dialog.setVisible(true);   //设置组件可见
      }
   }
}

package 第十五周;
import java.awt.*;
import javax.swing.*;
 
/**
 * @version 1.04 2015-06-12
 * @author Cay Horstmann
 */
public class ColorChooserTest          //框架整体框架
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() -> {
         JFrame frame = new ColorChooserFrame();
         frame.setTitle("ColorChooserTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

运行结果如下：

         

      

 实验总结：

     本周重点学了菜单和对话框，包括在菜单栏上添加菜单项，嵌套菜单，以及弹出菜单的使用，还有对话框的很多类型，有选择对话框，确认对话框，消息对话框，还有确认对话框。本周的实验都是验证性实验，通过看书，注释，网上查找，还有问同学就感觉是懂了点，但是理解的还不是很透彻，我会在课余时间自己看着书多敲几遍，多理解理解。