柏竹
柏竹
2020-02-18
目录

Java事件

# Java事件

# 动作事件

Class ActionEvent

java.lang.Object java.util.EventObject java.awt.AWTEvent java.awt.event.ActionEvent

ActionEvent类 监听控件动作，ActionListener接口 也可实现处理事件监听

抽象方法

actionPerformed(ActionEvent e); 控件回车

# 焦点事件监听器

Class FocusEvent

java.lang.Object java.util.EventObject java.awt.AWTEvent java.awt.event.ComponentEvent java.awt.event.FocusEvent

FocusEvent类 控件焦点监听，以光标视为焦点，失去或激活都会触发事件，FocusListener接口 也可实现处理事件监听

抽象方法

focusGained(FocusEvent e); 获取焦点

focusLost(FocusEvent e); 失去焦点

# 键盘事件

Class KeyEvent

java.lang.Object java.util.EventObject java.awt.AWTEvent java.awt.event.ComponentEvent java.awt.event.InputEvent java.awt.event.KeyEvent

KeyEvent类 键盘监听，KeyListener接口 也可实现处理事件监听

抽象方法

keyTyped(KeyEvent e); 点击

KeyPressed(keyEvent e); 被按下（未松也触发）

KeyReleased(keyEvent e); 松开释放

方法自查API

注意：KeyEvent类中以“VK_”为前缀的静态常量代表键盘的keyCode（键盘按键

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

public class KeyEventTest extends JFrame {

    private JTextField jtf = new JTextField(3);
    private JLabel jl = new JLabel("H");
    private Container container = getContentPane();

    public KeyEventTest(){
        setBounds(400, 300, 90, 80);
        setDefaultCloseOperation(3);
        jtf.setFont(new Font("微软雅黑",Font.PLAIN,16));
        jl.setFont(new Font("微软雅黑",Font.PLAIN,16));
        //窗体流布局
        container.setLayout(new FlowLayout());
        //添加组件
        container.add(jtf);
        container.add(jl);

        jtf.addKeyListener(new KeyListener() {
            @Override
            public void keyTyped(KeyEvent e) {
                System.out.println("点击了键盘");
            }

            @Override
            public void keyPressed(KeyEvent e) {
                System.out.println(e.getKeyText(e.getKeyCode()));
            }

            @Override
            public void keyReleased(KeyEvent e) {
                jtf.setText("");
                jl.setText(e.getKeyText(e.getKeyCode()));
            }
        });

        setVisible(true);
    }

    public static void main(String[] args) {
        new KeyEventTest();
    }
}

# 鼠标事件

Class MouseEvent

java.lang.Object java.util.EventObject java.awt.AWTEvent java.awt.event.ComponentEvent java.awt.event.InputEvent java.awt.event.MouseEvent

MouseEvent类 键盘监听类，MouseListener接口也可实现处理事件监听

MouseListener接口有5个抽象方法，分为不同的触发方式

mouseEntered(MouseEvent e);  鼠标移入组件触发\

mousePressed(MouseEvent e); 鼠标按下触发

mouseReleased(MouseEvent e); 鼠标释放触发

mouseClicked(MouseEvent e); 鼠标单击触发

mouseExited(MouseEvent e); 鼠标移出组件触发

方法自查API

MouseEvent类静态常量

静态常量 值 键
BUTTON1 1 鼠标左键
BUTTON2 2 鼠标滚轮
BUTTON3 3 鼠标右键
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

public class MouseEventTest extends JFrame implements MouseListener {

    private Container c = getContentPane();
    private JButton jb = new JButton("清空测试");
    private JLabel jl = new JLabel("H");
    private JTextArea jta = new JTextArea(15,35);
    private JScrollPane jsp = new JScrollPane(jta);
    private String scr = "";
    private static String tap = "(暂无)";

    public MouseEventTest(){
        setLayout(new FlowLayout());
        setDefaultCloseOperation(3);
        setBounds(400, 300, 400, 330);

        //边框颜色
        jsp.setBorder(BorderFactory.createLineBorder(Color.RED));

        c.add(jb);
        c.add(jl);
        c.add(jsp);

        //添加监听器
        jb.addMouseListener(this);
        jta.addMouseListener(this);
        jb.addActionListener(new AbstractAction() {
            @Override
            public void actionPerformed(ActionEvent e) {
                jta.setText("");
            }
        });
        setVisible(true);
    }


    //鼠标移入组件
    @Override
    public void mouseEntered(MouseEvent e) {
        if (e.getSource() == jb){
            scr = "按钮：";
        }
        if (e.getSource() == jta){
            scr = "文本框：";
        }
        jl.setText(scr+"移入组件");
    }
    //鼠标移出组件
    @Override
    public void mouseExited(MouseEvent e){
        jl.setText(scr+"移出组件");
    }
    //鼠标释放
    @Override
    public void mouseReleased(MouseEvent e){
        annpanduan(e);
        jl.setText(scr+"松开"+tap);
        jta.append(scr+"松开"+tap+"\n");
    }

    //鼠标按下
    @Override
    public void mousePressed(MouseEvent e){
        annpanduan(e);
        jl.setText(scr+"按下"+tap);
        jta.append(scr+"按下"+tap+"\n");

    }

    //鼠标单击
    @Override
    public void mouseClicked(MouseEvent e){
        annpanduan(e);
        jl.setText(scr+"单击"+tap);
        jta.append(scr+"单击"+tap+"\n");
    }

    public static void annpanduan(MouseEvent e){
        int source = e.getButton();
        switch(source){
            case 1 : tap = "(左键)"; break;
            case 2 : tap = "(中键)"; break;
            case 3 : tap = "(右键)"; break;
        }
    }

    public static void main(String[] args) {
        new MouseEventTest();
    }
    
}

# 窗体事件

# 窗体焦点事件

WindowFocusListener接口，捕获当前窗体焦点变化 抽象方法

windowGainedFocus(WindowEvent e);  获取焦点触发

windowLosetFocus(WindowEvent e);  失去焦点触发

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

public class WindowFocusTest extends JFrame implements WindowFocusListener {

    public WindowFocusTest(){
        setBounds(400,300,400,300);
        setDefaultCloseOperation(3);
        //为窗体添加焦点事件
        addWindowFocusListener(this);
        setVisible(true);
    }

    @Override
    public void windowGainedFocus(WindowEvent e){//获取焦点
        System.out.println("获取焦点");
    }
    @Override
    public void windowLostFocus(WindowEvent e){//失去焦点
        System.out.println("失去焦点");
    }

    public static void main(String[] args) {
        new WindowFocusTest();
    }
}

# 窗体状态事件

WindowStateListener接口，捕获当前窗体正常、最大、最小化的变化 抽象方法

windowStateChanged(WindowEvent e);  窗体发生变化时触发

窗体状态变化后，获取状态的方法

（int）getNewState()  获取窗体 现在 的状态

（int）getOldState()  获取窗体 以前 的状态

窗体状态的静态常量

静态常量 值 键
NORMAL 0 正常化
ICONIFIED 1 最小化
MAXIMIZED_BOTH 6 最大化
import javax.swing.*;
import java.awt.event.WindowEvent;
import java.awt.event.WindowFocusListener;
import java.awt.event.WindowStateListener;

public class WindowBasicTest extends JFrame implements WindowFocusListener, WindowStateListener {

    public WindowBasicTest(){
        setBounds(400,300,400,300);
        setDefaultCloseOperation(3);
        //为窗体添加焦点事件
        addWindowFocusListener(this);
        addWindowStateListener(this);
        setVisible(true);
    }

    @Override
    public void windowGainedFocus(WindowEvent e){//获取焦点
        System.out.println("获取焦点");
    }
    @Override
    public void windowLostFocus(WindowEvent e){//失去焦点
        System.out.println("失去焦点");
    }

    @Override
    public void windowStateChanged(WindowEvent e){//窗体发生变化
        //原旧状态 --> 新状态
        System.out.println(VaryString(e.getOldState())+" --> "+VaryString(e.getNewState()));
    }
    public String VaryString(int e){
        String scr = null;
        switch(e){
            case 0: scr = "正常化";break;
            case 1: scr = "最小化";break;
            case 6: scr = "最大化";break;
            default: scr = "最小化";break;
        }
        return scr;
    }

    public static void main(String[] args) {
        new WindowBasicTest();
    }
}

# 其他窗体事件

WindowListener接口，捕获窗体的变化情况 抽象方法

windowActivated(WindowEvent e);  激活触发（类似焦点

windowDeactivated(WindowEvent e); 非激活触发

windowIconified(WindowEvent e); 最小化触发

windowDeiconified(WindowEvent e); 非最小化触发

windowOpened(WindowEvent e); 窗口打开触发

windowClosing(WindowEvent e); 关闭窗口触发

windowClosed(WindowEvent e); 已关闭窗口触发

# 选项事件

Class ItemEvent

java.lang.Object java.util.EventObject java.awt.AWTEvent java.awt.event.ItemEvent

ItemEvent类 选项监听类，ItemListener接口也可实现处理事件监听 抽象方法

itemStateChanged(ItemEvent e); 选定/取消 时触发

处理选项方法

（object）getItem()  获取选中对象 （int）getStateChange()  获取选中的状态

getStateChange()方法 返回的静态常量

静态常量 值 键
SELECTED 1 选中
DESELECTED 2 取消
import javax.swing.*;
import java.awt.*;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

public class OptionEventTest extends JFrame implements ItemListener {

   private String[] listdata = {"全部", "复选框", "单选按钮"};
   private JComboBox jcblist = new JComboBox(listdata);
   //选中内容
   private JPanel jpl = new JPanel();
   private JRadioButton jrb = new JRadioButton("单选按钮");
   private JCheckBox jcb = new JCheckBox("复选框");
   private Container c = getContentPane();

   public OptionEventTest() {
       setBounds(400, 300, 200, 140);
       setDefaultCloseOperation(3);

       jpl.add(jrb);
       jpl.add(jcb);
       jpl.setSize(200, 280);
       jpl.setBorder(BorderFactory.createTitledBorder("显示区"));

       c.add(jcblist, BorderLayout.NORTH);
       c.add(jpl, BorderLayout.CENTER);

       //监听
       jrb.addItemListener(this);
       jcb.addItemListener(this);
       jcblist.addItemListener(new ItemListener() {
           @Override
           public void itemStateChanged(ItemEvent e) {
               switch ((String) e.getItem()) {
                   case "单选按钮":
                       jrb.setVisible(true);
                       jcb.setVisible(false);
                       break;
                   case "复选框":
                       jrb.setVisible(false);
                       jcb.setVisible(true);
                       break;
                   default:
                       jrb.setVisible(true);
                       jcb.setVisible(true);
                       break;
               }
           }
       });

       setVisible(true);
   }

   @Override
   public void itemStateChanged(ItemEvent e) {// 选中 ro 取消
       //单选按钮和复选框的父类
       JToggleButton tmp = (JToggleButton) e.getSource();
       String type = tmp.getText();
       switch (e.getStateChange()) {
           case 1:
               System.out.println("选中" + type);
               break;
           case 2:
               System.out.println("取消" + type);
               break;
           default:
               System.out.println("错误");
               break;
       }
   }

   public static void main(String[] args) {
       new OptionEventTest();
   }
}
#Java
上次更新: 2023/03/12, 00:43:49

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