java新手笔记27 监听器类

1、外部类监听

package com.yfs.javase;

import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
//外部类监听
public class FrameDemo1 extends Frame {
	Button but1 = new Button(" + ");
	Button but2 = new Button(" - ");
	TextField text = new TextField(20);
	public FrameDemo1() {
		super("event1外部类");
		setLocation(200, 150);
		// 设置布局
		setLayout(new FlowLayout());
		text.setText("100");
		text.setEditable(false);
		//创建监听器对象
		MyListener listener = new MyListener(this);
		//建立关联  监听器添加到按钮
		but1.addActionListener(listener);
		but2.addActionListener(listener);
		//text.getText();//取text值
		add(but1);
		add(text);
		add(but2);
		setResizable(false);
        pack();
		// 默认隐藏 设置显示
		setVisible(true);
	}

	public static void main(String[] args) {
			new FrameDemo1();
	}

}

//开发监听器  实现监听器接口
class MyListener implements ActionListener {
	private FrameDemo1 frame;
	//通过构造方法强制传入窗体对象
	public MyListener(FrameDemo1 frame) {
		this.frame = frame;
	}
   //ActionEvent  事件对象
	@Override
	public void actionPerformed(ActionEvent e) {
//		System.out.println("按钮被单击了....");
//		//事件对象
		System.out.println(e.getActionCommand());//控件字符
//		System.out.println(e.getSource());//事件源
		//从text取值
		//依赖传入对象
		//FrameDemo1 frame = new FrameDemo1();//不能创建窗体对象
		int val = Integer.parseInt(frame.text.getText());
		System.out.println("val =  " + val);
		String opt = e.getActionCommand().trim();
		if("+".equals(opt)){
			frame.text.setText(String.valueOf(val + 1));
		} else if("-".equals(opt)){
			frame.text.setText(String.valueOf(val - 1));
		} 

	}

}

2.内部类监听

package com.yfs.javase;

import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
//内部类监听
public class FrameDemo2 extends Frame {
	Button but1 = new Button(" + ");
	Button but2 = new Button(" - ");
	TextField text = new TextField(20);
	public FrameDemo2() {
		super("event1内部类");
		setLocation(200, 150);
		// 设置布局
		setLayout(new FlowLayout());
		text.setText("100");
		text.setEditable(false);
		//创建监听器对象
		Listener listener = new Listener();
		//建立关联  监听器添加到按钮
		but1.addActionListener(listener);
		but2.addActionListener(listener);
		//text.getText();//取text值
		add(but1);
		add(text);
		add(but2);
		setResizable(false);
        pack();
		// 默认隐藏 设置显示
		setVisible(true);
	}
	//内部类
	class Listener implements ActionListener {
		@Override
		public void actionPerformed(ActionEvent e) {
			int val = Integer.parseInt(text.getText());
			String opt = e.getActionCommand().trim();
			System.out.println(opt);
			if("+".equals(opt)){
				text.setText(String.valueOf(val + 1));
			} else if("-".equals(opt)){
				text.setText(String.valueOf(val - 1));
			}
		}

	}

	public static void main(String[] args) {
			new FrameDemo2();
	}

}

3.自监听

package com.yfs.javase;

import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
//自监听
public class FrameDemo3 extends Frame implements ActionListener {
	Button but1 = new Button(" + ");
	Button but2 = new Button(" - ");
	TextField text = new TextField(20);
	public FrameDemo3() {
		super("event1自监听类");
		setLocation(200, 150);
		// 设置布局
		setLayout(new FlowLayout());
		text.setText("100");
		text.setEditable(false);

		//建立关联  监听器添加到按钮
		but1.addActionListener(this);
		but2.addActionListener(this);
		//text.getText();//取text值
		add(but1);
		add(text);
		add(but2);
		setResizable(false);
        pack();
		// 默认隐藏 设置显示
		setVisible(true);
	}

	public static void main(String[] args) {
			new FrameDemo3();
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		//事件处理代码
		int val = Integer.parseInt(text.getText());
		String opt = e.getActionCommand().trim();
		if("+".equals(opt)){
			text.setText(String.valueOf(val + 1));
		} else if("-".equals(opt)){
			text.setText(String.valueOf(val - 1));
		}
	}

}

4.匿名类监听

package com.yfs.javase;

import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
//匿名类监听
public class FrameDemo4 extends Frame {
	Button but1 = new Button(" + ");
	Button but2 = new Button(" - ");
	TextField text = new TextField(20);
	public FrameDemo4() {
		super("event1匿名监听类");
		setLocation(200, 150);
		// 设置布局
		setLayout(new FlowLayout());
		text.setText("100");
		text.setEditable(false);

		//建立关联  监听器添加到按钮
		but1.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent arg0) {
				int val = Integer.parseInt(text.getText()) + 1;
				text.setText(String.valueOf(val));

			}
		});
		but2.addActionListener(new ActionListener() {

			@Override
			public void actionPerformed(ActionEvent arg0) {
				int val = Integer.parseInt(text.getText()) - 1;
				text.setText(String.valueOf(val));

			}
		});
		//text.getText();//取text值
		add(but1);
		add(text);
		add(but2);
		setResizable(false);
        pack();
		// 默认隐藏 设置显示
		setVisible(true);
	}

	public static void main(String[] args) {
			new FrameDemo4();
	}

}

5.背景图片

package com.yfs.javase;

import java.awt.FlowLayout;
import java.awt.Image;

import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
//匿名类监听
public class FrameDemo5 extends JFrame {

	public FrameDemo5() {
		super("event1匿名监听类");
		setBounds(200, 150, 400, 400);
		setLayout(new FlowLayout());
		//标题图片
		Image logo = new ImageIcon("img/m.gif").getImage();
		setIconImage(logo);
		//图片label
		Icon ic = new ImageIcon("img\\index.gif");
		JLabel jl = new JLabel(ic);

		JButton but = new JButton(new ImageIcon("img/1_03.gif"));
		add(but);
		add(jl);
		setResizable(false);
        //pack();
		setVisible(true);
	}

	public static void main(String[] args) {
			new FrameDemo5();
	}

}