Java窗体中的事件处理之Button

浅浅的花香味﹌ 2022-07-13 01:39 111阅读 0赞

Java中的事件处理机制：

监听器对象是一个实现了特定监听器接口（Listener Interface）类的实例

事件源是一个能够注册监听器对象并发送事件对象的对象

当事件发送时候，事件源将事件对象传递给所以注册的监听器

监听器对象将利用事件对象中的信息决定如何做出响应

创建一个Buttontest窗体，里面包含三个按钮，点击按钮改变面板的背景颜色：

package com.Project_Button01;
    
    import java.awt.Color;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import java.awt.event.MouseEvent;
    import java.awt.event.MouseListener;
    
    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JPanel;
    
    public class ButtonFrame extends JFrame{
    	public ButtonFrame(){
    		this.setTitle("Buttontest");
    		this.setSize(400,400);
    		
    		//create button
    		JButton yellowbutton=new JButton("Yellow");
    		JButton bluebutton=new JButton("Blue");
    		JButton redbutton=new JButton("red");
    		
    		//add buttons to panel
    		buttonPanel=new JPanel();
    		buttonPanel.add(yellowbutton);
    		buttonPanel.add(bluebutton);
    		buttonPanel.add(redbutton);
    		
    		//add panel to frame
    		this.add(buttonPanel);
    		
    		//craete button actions
    		yellowbutton.addActionListener(new ColorAction(Color.YELLOW));
    		bluebutton.addActionListener(new ColorAction(Color.BLUE));
    		redbutton.addActionListener(new ColorAction(Color.RED));
    		yellowbutton.addMouseListener(new MouseListener() {
    			
    			@Override
    			public void mouseReleased(MouseEvent e) {
    				// TODO Auto-generated method stub
    				System.out.println("mouseReleased");
    			}
    			
    			@Override
    			public void mousePressed(MouseEvent e) {
    				// TODO Auto-generated method stub
    				System.out.println("mousePressed");
    			}
    			
    			@Override
    			public void mouseExited(MouseEvent e) {
    				// TODO Auto-generated method stub
    				System.out.println("mouseExited");
    			}
    			
    			@Override
    			public void mouseEntered(MouseEvent e) {
    				// TODO Auto-generated method stub
    				System.out.println("mouseEntered");
    			}
    			
    			@Override
    			public void mouseClicked(MouseEvent e) {
    				// TODO Auto-generated method stub
    				
    			}
    		});
    	}
    	
    	public class ColorAction implements ActionListener{
    		public ColorAction(Color c){
    			backgroundColor=c;
    		}
    		
    		private Color backgroundColor;
    
    		@Override
    		public void actionPerformed(ActionEvent e) {
    			// TODO Auto-generated method stub
    			buttonPanel.setBackground(backgroundColor);
    		}
    	}
    	private JPanel buttonPanel;
    }

程序入口：

package com.Project_Button01;
    
    import java.awt.EventQueue;
    
    import javax.swing.JFrame;
    
    public class StartMian {
    
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		EventQueue.invokeLater(new Runnable() {
    			
    			@Override
    			public void run() {
    				// TODO Auto-generated method stub
    				ButtonFrame frame=new ButtonFrame();
    				frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    				frame.setVisible(true);
    			}
    		});
    	}
    
    }