Java基础（Swing组件之动作事件监听器）

例如:

package Swing组件;

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

public class Demo12 extends JFrame {
          
   
    public Demo12(){
          
   
        Container c =getContentPane();
        setBounds(100,100,500,100);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);

        JPanel centerP = new JPanel();
        centerP.setLayout(new FlowLayout());
        c.add(centerP,BorderLayout.CENTER);

        JPanel southP = new JPanel();
        JLabel console = new JLabel("点击组件");
        southP.add(console);
        c.add(southP,BorderLayout.SOUTH);

        JButton btn = new JButton("按钮");
        centerP.add(btn);
        btn.addActionListener(new ActionListener() {
          
   
            @Override
            public void actionPerformed(ActionEvent e) {
          
   
                console.setText("按钮被点击");
            }
        });
        JTextField jt = new JTextField(10);
        centerP.add(jt);
        jt.addActionListener(new ActionListener() {
          
   
            @Override
            public void actionPerformed(ActionEvent e) {
          
   
                Object obj = e.getSource(); //返回obj对象值
                JTextField jtTmp =(JTextField)obj;  //强制转化为文本框
                System.out.println(jtTmp.getText());
                console.setText("文本框中点击了回车");
            }
        });
        JCheckBox jc = new JCheckBox("多选框");
        centerP.add(jc);
        jc.addActionListener(new ActionListener() {
          
   
            @Override
            public void actionPerformed(ActionEvent e) {
          
   
                console.setText("多选框被点击");
            }
        });
        JRadioButton jr = new JRadioButton("单选框");
        centerP.add(jr);
        jr.addActionListener(new ActionListener() {
          
   
            @Override
            public void actionPerformed(ActionEvent e) {
          
   
                console.setText("单选框被点击");
            }
        });
        String values[] = {
          
   "选项1","选项2","选项3"};
        JComboBox jb = new JComboBox(values);
        centerP.add(jb);
        jb.addActionListener(new ActionListener() {
          
   
            @Override
            public void actionPerformed(ActionEvent e) {
          
   
                console.setText("下拉列表被选择");
            }
        });
        c.validate();  //重新验证一下容器中的组件


    }

    public static void main(String[] args) {
          
   
        new Demo12();
    }
}

运行结果：