这是我做的计算器的排版，显得有些笨拙，上面两个文本框用于用户输入数字的，中间的五个是按钮，下面一个是显示答案的文本框
*事件：当用户在界面上执行一个操作，例如按下键盘、拖动或者单击鼠标时，都将产生一个事件。Java中事件是用来描述不同类型用户操作的对象，Java中有很多不同类型的事件。例如：单击，双击，右击，拖动，键盘的按下、释放，文本域内容改变等。

事件源：产生事件的组件就是一个事件源。例如，当在一个Button上单击鼠标是，将产生一个ActionEvent类型的事件，而这个Button就是事件源

事件监听器：就是调用事件处理方法的对象。当界面操作事件产生并被发送到产生事件的组件时，该组件将把事件发送给能接受和处理该事件的监听器。*
这里面的重要的是事件的监听，我是通过事件源是按钮，事件是鼠标移动。而这一动作会被监听器捕捉到，监听器就会创建一个移动事件类并自动调用监听器接口(里面都是抽象方法，必须全部实现)中的一个方法，对这一动作做出反应

import java.awt.*;
import java.awt.event.*;
/**
*@author 作者 Your-Name：
*@version 创建时间：
*类说明：实现GUI计算器
*/
public class JiSuanQi {static int x;static int y;public static void main(String[] args) {// TODO Auto-generated method stubFrame f = new Frame("计算器");f.setBounds(100,100,400,400);f.setVisible(true);f.setLayout(null);f.addWindowListener(new WindowAdapter() {public void windowClosing(WindowEvent e){System.exit(0);}});TextField t1 = new TextField();t1.setBounds(100,80,100,30);f.add(t1);TextField t2 = new TextField();t2.setBounds(100,160,100,30);f.add(t2);TextField t3 = new TextField();t3.setBounds(100,300,100,30);f.add(t3);Button b1 = new Button("+");b1.setBounds(80,240,30,20);b1.addMouseListener(new MouseListener() {public void mouseClicked(MouseEvent e){}public void mouseEntered(MouseEvent e){}public void mouseExited(MouseEvent e){}public void mousePressed(MouseEvent e){}public void mouseReleased(MouseEvent e){x = Integer.parseInt(t1.getText());//获取文本框1里面的数字，文本框中都是字符串所以要用这个方法强转为整数y = Integer.parseInt(t2.getText());t3.setText("和为: " + (x + y));//对文本框3添加字符串}});f.add(b1);Button b2 = new Button("-");b2.setBounds(130,240,30,20);b2.addMouseListener(new MouseListener() {public void mouseClicked(MouseEvent e){}public void mouseEntered(MouseEvent e){}public void mouseExited(MouseEvent e){}public void mousePressed(MouseEvent e){}public void mouseReleased(MouseEvent e){x = Integer.parseInt(t1.getText());y = Integer.parseInt(t2.getText());t3.setText("差为: " + (x - y));}});f.add(b2);Button b3 = new Button("*");b3.setBounds(170,240,30,20);b3.addMouseListener(new MouseListener() {public void mouseClicked(MouseEvent e){}public void mouseEntered(MouseEvent e){}public void mouseExited(MouseEvent e){}public void mousePressed(MouseEvent e){}public void mouseReleased(MouseEvent e){x = Integer.parseInt(t1.getText());y = Integer.parseInt(t2.getText());t3.setText("积为: " + (x * y));}});f.add(b3);Button b4 = new Button("/");b4.setBounds(210,240,30,20);b4.addMouseListener(new MouseListener() {public void mouseClicked(MouseEvent e){}public void mouseEntered(MouseEvent e){}public void mouseExited(MouseEvent e){}public void mousePressed(MouseEvent e){}public void mouseReleased(MouseEvent e){x = Integer.parseInt(t1.getText());y = Integer.parseInt(t2.getText());if(y == 0){t3.setText("除数不能为0");}else{t3.setText("商为: " + (x / y));}}});f.add(b4);Button b5 = new Button("清空");b5.setBounds(250,240,30,30);b5.addMouseListener(new MouseListener() {public void mouseClicked(MouseEvent e){}public void mouseEntered(MouseEvent e){}public void mouseExited(MouseEvent e){}public void mousePressed(MouseEvent e){}public void mouseReleased(MouseEvent e){t1.setText("");t2.setText("");t3.setText("");}});f.add(b5);}}