java图形化界面监听事件_Java自学-图形界面事件监听

「爱情、让人受尽委屈。」 2022-11-06 04:55 143阅读 0赞

Swing 如何进行事件监听

示例 1 : 按钮监听

创建一个匿名类实现ActionListener接口，当按钮被点击时，actionPerformed方法就会被调用

![b8f5696381d34a7f53240a58b5003faf.png][]

package gui;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.ImageIcon;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

public class TestGUI \{

public static void main(String\[\] args) \{

JFrame f = new JFrame("LoL");

f.setSize(400, 300);

f.setLocation(580, 200);

f.setLayout(null);

final JLabel l = new JLabel();

ImageIcon i = new ImageIcon("e:/project/j2se/shana.png");

l.setIcon(i);

l.setBounds(50, 50, i.getIconWidth(), i.getIconHeight());

JButton b = new JButton("隐藏图片");

b.setBounds(150, 200, 100, 30);

// 给按钮 增加 监听

b.addActionListener(new ActionListener() \{

// 当按钮被点击时，就会触发 ActionEvent事件

// actionPerformed 方法就会被执行

public void actionPerformed(ActionEvent e) \{

l.setVisible(false);

\});

f.add(l);

f.add(b);

f.setDefaultCloseOperation(JFrame.EXIT\_ON\_CLOSE);

f.setVisible(true);

示例 2 : 键盘监听

键盘监听器： KeyListener

keyPressed 代表 键被按下

keyReleased 代表 键被弹起

keyTyped 代表 一个按下弹起的组合动作

KeyEvent.getKeyCode() 可以获取当前点下了哪个键

![a707aec309620478b26803e13b0a4513.png][]

package gui;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.KeyEvent;

import java.awt.event.KeyListener;

import javax.swing.ImageIcon;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

public class TestGUI \{

public static void main(String\[\] args) \{

JFrame f = new JFrame("LoL");

f.setSize(400, 300);

f.setLocation(580, 200);

f.setLayout(null);

final JLabel l = new JLabel();

ImageIcon i = new ImageIcon("e:/project/j2se/shana.png");

l.setIcon(i);

l.setBounds(50, 50, i.getIconWidth(), i.getIconHeight());

// 增加键盘监听

f.addKeyListener(new KeyListener() \{

// 键被弹起

public void keyReleased(KeyEvent e) \{

// 39代表按下了 “右键”

if (e.getKeyCode() == 39) \{

// 图片向右移动 (y坐标不变，x坐标增加)

l.setLocation(l.getX() + 10, l.getY());

//键被按下

public void keyPressed(KeyEvent e) \{

// TODO Auto-generated method stub

// 一个按下弹起的组合动作

public void keyTyped(KeyEvent e) \{

\});

f.add(l);

f.setDefaultCloseOperation(JFrame.EXIT\_ON\_CLOSE);

f.setVisible(true);

示例 3 : 鼠标监听

MouseListener 鼠标监听器

mouseReleased 鼠标释放

mousePressed 鼠标按下

mouseExited 鼠标退出

mouseEntered 鼠标进入

mouseClicked 鼠标点击

在本例中，使用mouseEntered，当鼠标进入图片的时候，图片就移动位置

![82b3daca8f86b91b3f97629f8bb7ee0c.png][]

package gui;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;

import java.util.Random;

import javax.swing.ImageIcon;

import javax.swing.JFrame;

import javax.swing.JLabel;

public class TestGUI \{

public static void main(String\[\] args) \{

final JFrame f = new JFrame("LoL");

f.setSize(800, 600);

f.setLocationRelativeTo(null);

f.setLayout(null);

final JLabel l = new JLabel();

ImageIcon i = new ImageIcon("e:/project/j2se/shana\_heiheihei.png");

l.setIcon(i);

l.setBounds(375, 275, i.getIconWidth(), i.getIconHeight());

f.add(l);

l.addMouseListener(new MouseListener() \{

// 释放鼠标

public void mouseReleased(MouseEvent e) \{

// TODO Auto-generated method stub

// 按下鼠标

public void mousePressed(MouseEvent e) \{

// TODO Auto-generated method stub

// 鼠标退出

public void mouseExited(MouseEvent e) \{

// TODO Auto-generated method stub

// 鼠标进入

public void mouseEntered(MouseEvent e) \{

Random r = new Random();

int x = r.nextInt(f.getWidth() - l.getWidth());

int y = r.nextInt(f.getHeight() - l.getHeight());

l.setLocation(x, y);

// 按下释放组合动作为点击鼠标

public void mouseClicked(MouseEvent e) \{

// TODO Auto-generated method stub

\});

f.setDefaultCloseOperation(JFrame.EXIT\_ON\_CLOSE);

f.setVisible(true);

示例 4 : 适配器

MouseAdapter 鼠标监听适配器

一般说来在写监听器的时候，会实现MouseListener。

但是MouseListener里面有很多方法实际上都没有用到，比如mouseReleased ，mousePressed，mouseExited等等。

这个时候就可以使用 鼠标监听适配器，MouseAdapter 只需要重写必要的方法即可。

package gui;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.util.Random;

import javax.swing.ImageIcon;

import javax.swing.JFrame;

import javax.swing.JLabel;

public class TestGUI \{

public static void main(String\[\] args) \{

final JFrame f = new JFrame("LoL");

f.setSize(800, 600);

f.setLocationRelativeTo(null);

f.setLayout(null);

final JLabel l = new JLabel("");

ImageIcon i = new ImageIcon("e:/project/j2se/shana\_heiheihei.png");

l.setIcon(i);

l.setBounds(375, 275, i.getIconWidth(), i.getIconHeight());

f.add(l);

// MouseAdapter 适配器，只需要重写用到的方法，没有用到的就不用写了

l.addMouseListener(new MouseAdapter() \{

// 只有mouseEntered用到了

public void mouseEntered(MouseEvent e) \{

Random r = new Random();

int x = r.nextInt(f.getWidth() - l.getWidth());

int y = r.nextInt(f.getHeight() - l.getHeight());

l.setLocation(x, y);

\});

f.setDefaultCloseOperation(JFrame.EXIT\_ON\_CLOSE);

f.setVisible(true);

[b8f5696381d34a7f53240a58b5003faf.png]: /images/20221023/f7d04502f44141119ede28e482b9758c.png
[a707aec309620478b26803e13b0a4513.png]: /images/20221023/b08017067eb6438ba146a4e82a26f82a.png
[82b3daca8f86b91b3f97629f8bb7ee0c.png]: /images/20221023/28918400b079481797d2aa2699b79358.png