刘志梅2017710101152.《面向对象程序设计（java）》第十三周学习总结(代码片段)

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

/**
 * A frame with a button panel
 */
public class ButtonFrame extends JFrame

   private JPanel buttonPanel;     //内容窗格对象
   private static final int DEFAULT_WIDTH = 300;//宽度值300像素
   private static final int DEFAULT_HEIGHT = 200;//高度值200像素

   public ButtonFrame()
         
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

      // create buttons
      JButton yellowButton = new JButton("Yellow");
      JButton blueButton = new JButton("Blue");
      JButton redButton = new JButton("Red");

      buttonPanel = new JPanel();//创建JPanel

      // add buttons to panel
      buttonPanel.add(yellowButton);
      buttonPanel.add(blueButton);
      buttonPanel.add(redButton);

      // add panel to frame
      add(buttonPanel);
      //为每种颜色new一个对象
      // create button actions
      ColorAction yellowAction = new ColorAction(Color.YELLOW);
      ColorAction blueAction = new ColorAction(Color.BLUE);
      ColorAction redAction = new ColorAction(Color.RED);//生成三个相同的类对象（colouraction）
      //(注册机制)
      // associate actions with buttons
      yellowButton.addActionListener(yellowAction);
      blueButton.addActionListener(blueAction);
      redButton.addActionListener(redAction);
   

   /**
    * An action listener that sets the panel‘s background color.
    */
   private class ColorAction implements ActionListener
       //监听器接口ActionListener（监听器类且类名为ColorAction）
      private Color backgroundColor;

      public ColorAction(Color c)
      
         backgroundColor = c;
      

      public void actionPerformed(ActionEvent event)//ActionListener只有一个方法actionPerformed
      
         buttonPanel.setBackground(backgroundColor);
      
   

//只有容器组件有add方法

package button;

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

/**
 * A frame with a button panel
 */
public class ButtonFrame extends JFrame

   private JPanel buttonPanel;//
   private static final int DEFAULT_WIDTH = 300;//宽为300px
   private static final int DEFAULT_HEIGHT = 200;//长为200px
//注释掉这个构造器之后只能显示一个窗格，面板上没有内容
/*   public ButtonFrame()//构造器
         
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);//决定框架大小

      // create buttons  创建按钮
      JButton yellowButton = new JButton("Yellow");//Yellow字符串是显示在按钮上的文本
      JButton blueButton = new JButton("Blue");
      JButton redButton = new JButton("Red");

      buttonPanel = new JPanel();//使 buttonPanel指向一个具体的容器对象

      // add buttons to panel
      buttonPanel.add(yellowButton);//将按钮添加到面板中
      buttonPanel.add(blueButton);
      buttonPanel.add(redButton);

      // add panel to frame
      add(buttonPanel);

      // create button actions 
      //生成三个监听器类对象   当事件发生时，事件源将事件对象传递给所有注册的监听器
      //颜色值在Color类中，通过类名调用
      ColorAction yellowAction = new ColorAction(Color.YELLOW);
      ColorAction blueAction = new ColorAction(Color.BLUE);
      ColorAction redAction = new ColorAction(Color.RED);

      // associate actions with buttons  将操作与按钮相关联
      yellowButton.addActionListener(yellowAction);
      //注释掉之后程序可以运行，点击按钮，背景色不变
      blueButton.addActionListener(blueAction);
      redButton.addActionListener(redAction);
   */
   public ButtonFrame()//构造器
      
      buttonPanel = new JPanel();//使 buttonPanel指向一个具体的容器对象
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);//决定框架大小
      add(buttonPanel);
      makeButton("Yellow",Color.YELLOW);
      makeButton("blue",Color.BLUE);
      makeButton("red",Color.RED);
      makeButton("green",Color.GREEN);
   
    public void makeButton(String name,Color BackgroundColor)
    
        JButton button = new JButton(name);
        buttonPanel.add(button);
        ColorAction action = new ColorAction(BackgroundColor);//初始化一个颜色对象
        button.addActionListener(action);//添加一个事件监听器
    
   /**
    * An action listener that sets the panel‘s background color.
    */
   //监听器类，类名是ColorAction
   private class ColorAction implements ActionListener//实现了一个监听器接口
   
      private Color backgroundColor;

      public ColorAction(Color c)
      
         backgroundColor = c;
      

      public void actionPerformed(ActionEvent event)
      
         buttonPanel.setBackground(backgroundColor);
      
   

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

/**
 * @version 1.32 2015-06-12
 * @author Cay Horstmann
 */
public class PlafTest

   public static void main(String[] args)
   
      EventQueue.invokeLater(() -> 
         JFrame frame = new PlafFrame();
         frame.setTitle("PlafTest");//框架标题（“PlafTest”）
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      );
   

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;

/**
 * A frame with a button panel for changing look-and-feel
 */
public class PlafFrame extends JFrame

   private JPanel buttonPanel;

   public PlafFrame()//按钮面板
   
      buttonPanel = new JPanel();

      UIManager.LookAndFeelInfo[] infos = UIManager.getInstalledLookAndFeels();
      for (UIManager.LookAndFeelInfo info : infos)
         makeButton(info.getName(), info.getClassName());

      add(buttonPanel);
      pack();
   

   /**
    * Makes a button to change the pluggable look-and-feel.
    * @param name the button name
    * @param className the name of the look-and-feel class
    */
   private void makeButton(String name, String className)
   
      // add button to panel

      JButton button = new JButton(name);
      buttonPanel.add(button);

      // set button action

      button.addActionListener(event -> 
         // button action: switch to the new look-and-feel
         try
         
            UIManager.setLookAndFeel(className);
            SwingUtilities.updateComponentTreeUI(this);
            pack();//调用静态UIManager.setLookAndFeel方法
         
         catch (Exception e)
         
            e.printStackTrace();
         
      );
   

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

/**
 * A frame with a panel that demonstrates color change actions.
 */
public class ActionFrame extends JFrame

   private JPanel buttonPanel;
   private static final int DEFAULT_WIDTH = 300;
   private static final int DEFAULT_HEIGHT = 200;

   public ActionFrame()
   
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

      buttonPanel = new JPanel();

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

      // add buttons for these actions
      buttonPanel.add(new JButton(yellowAction));
      buttonPanel.add(new JButton(blueAction));
      buttonPanel.add(new JButton(redAction));
      //为这些动作添加按钮
      // add panel to frame
      add(buttonPanel);

      // associate the Y, B, and R keys with names
      InputMap imap = buttonPanel.getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
      imap.put(KeyStroke.getKeyStroke("ctrl Y"), "panel.yellow");
      imap.put(KeyStroke.getKeyStroke("ctrl B"), "panel.blue");
      imap.put(KeyStroke.getKeyStroke("ctrl R"), "panel.red");

      // associate the names with actions
      ActionMap amap = buttonPanel.getActionMap();
      amap.put("panel.yellow", yellowAction);
      amap.put("panel.blue", blueAction);
      amap.put("panel.red", redAction);
   
   
   public class ColorAction extends AbstractAction//公共类ColorAction扩展了AbstractAction
   
      /**
       * Constructs a color action.
       * @param name the name to show on the button
       * @param icon the icon to display on the button
       * @param c the background color
       */
      public ColorAction(String name, Icon icon, Color c)//公共类ColorAction（字符串名称，图标，颜色）
      
         putValue(Action.NAME, name);
         putValue(Action.SMALL_ICON, icon);
         putValue(Action.SHORT_DESCRIPTION, "Set panel color to " + name.toLowerCase());
         putValue("color", c);
      

      public void actionPerformed(ActionEvent event)
      
         Color c = (Color) getValue("color");
         buttonPanel.setBackground(c);
      
   

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

/**
 * A component with mouse operations for adding and removing squares.
 */
public class MouseComponent extends JComponent

   private static final int DEFAULT_WIDTH = 300;//宽度定义为300像素
   private static final int DEFAULT_HEIGHT = 200;//高度为200像素

   private static final int SIDELENGTH = 10;
   private ArrayList<Rectangle2D> squares;
   private Rectangle2D current; // the square containing the mouse cursor

   public MouseComponent()
   
      squares = new ArrayList<>();
      current = null;//当前为零

      addMouseListener(new MouseHandler());
      addMouseMotionListener(new MouseMotionHandler());
   

   public Dimension getPreferredSize()  return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT);    
   
   public void paintComponent(Graphics g)
   
      Graphics2D g2 = (Graphics2D) g;

      // draw all squares
      for (Rectangle2D r : squares)
         g2.draw(r);
   

   /**
    * Finds the first square containing a point.
    * @param p a point
    * @return the first square that contains p
    */
   public Rectangle2D find(Point2D p)
   
      for (Rectangle2D r : squares)
      
         if (r.contains(p)) return r;
      
      return null;//返回null
   

   /**
    * Adds a square to the collection.
    * @param p the center of the square
    */
   public void add(Point2D p)
   
      double x = p.getX();
      double y = p.getY();

      current = new Rectangle2D.Double(x - SIDELENGTH / 2, y - SIDELENGTH / 2, SIDELENGTH,
            SIDELENGTH);
      squares.add(current);
      repaint(); //重画
   

   /**
    * Removes a square from the collection.
    * @param s the square to remove
    */
   public void remove(Rectangle2D s)
   
      if (s == null) return;
      if (s == current) current = null;
      squares.remove(s);
      repaint();
   

   private class MouseHandler extends MouseAdapter
   
      public void mousePressed(MouseEvent event)
      
         // add a new square if the cursor isn‘t inside a square
         current = find(event.getPoint());
         if (current == null) add(event.getPoint());
      

      public void mouseClicked(MouseEvent event)
      
         // remove the current square if double clicked
         current = find(event.getPoint());
         if (current != null && event.getClickCount() >= 2) remove(current);
      
   

   private class MouseMotionHandler implements MouseMotionListener
   
      public void mouseMoved(MouseEvent event)
      
         // set the mouse cursor to cross hairs if it is inside
         // a rectangle

         if (find(event.getPoint()) == null) setCursor(Cursor.getDefaultCursor());
         else setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
      

      public void mouseDragged(MouseEvent event)
      
         if (current != null)
         
            int x = event.getX();
            int y = event.getY();

            // drag the current rectangle to center it at (x, y)
            current.setFrame(x - SIDELENGTH / 2, y - SIDELENGTH / 2, SIDELENGTH, SIDELENGTH);
            repaint();//重新绘制画布，以显示新的鼠标位置
         
      
      

import javax.swing.*;

/**
 * A frame containing a panel for testing mouse operations
 */
public class MouseFrame extends JFrame

   public MouseFrame()//公共类MouseFrame
   
      add(new MouseComponent());
      pack();
   

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


public class dian //公关类dian
public static void main(String []args)

MyFrame f = new MyFrame();
f.launchFrame();





class MyFrame extends Frame
Label text2;
void launchFrame()
setTitle("学生点名系统");
setVisible(true);
Button btn1 = new Button("开始");
Button btn2 = new Button("结束");
Label text1 = new Label("学号：");
text2 = new Label("按下开始按钮开始点名");
Panel p=new Panel();

setBounds(300,300,300,400);

p.setBackground(Color.white);
p.setBounds(0,0,300,400);
p.setLayout(new FlowLayout(FlowLayout.CENTER,60,100));
//btn1.setBounds(20,20,50,20);
//btn2.setBounds(90,20,50,20);


add(p);
p.add(text1);//添加text1
p.add(text2);//添加text2
p.add(btn1);//添加btn1
p.add(btn2);//添加btn2
this.addWindowListener(new MyWindowMoniter());
btn1.addActionListener(new btnMoniter(this));
btn2.addActionListener(new btnMoniter(this));




class btnMoniter implements ActionListener 
MyFrame f;
btnMoniter(MyFrame f)
this.f=f;

public void actionPerformed(ActionEvent e)
String s=e.getActionCommand();
Random r=new Random();
int i=r.nextInt(50);
if(s=="开始") 
f.repaint();
f.text2.setText("正在点名！");

if(s=="结束")//如果s意为结束
f.repaint();//重新一次
f.text2.setText(""+i);





//window时间监听器，用于关闭window窗口
class MyWindowMoniter extends WindowAdapter
public void windowClosing(WindowEvent e)
System.exit(0);//退出