java例程练习（简单的计算器[调停者 设计模式 及 内部类 ]）

import java.awt.*;import java.awt.event.*;public class TestInnerClass {    public static void main(String[] args) {    new TFFrame().launchFrame();    }}class TFFrame extends Frame {public void launchFrame() {TextField num1 = new TextField(10);TextField num2 = new TextField(10);TextField num3 = new TextField(15);Label lbPlus = new Label("+");Button btnEqual = new Button("=");setLayout(new FlowLayout());add(num1);add(lbPlus);add(num2);add(btnEqual);add(num3);btnEqual.addActionListener(new MyMonitor(num1, num2, num3));pack();setVisible(true);}}class MyMonitor implements ActionListener {TextField num1,num2,num3;MyMonitor(TextField num1, TextField num2, TextField num3) {//用构造函数实现this.num1 = num1;this.num2 = num2;this.num3 = num3;}public void actionPerformed(ActionEvent e) {int n1 = Integer.parseInt(num1.getText());int n2 = Integer.parseInt(num2.getText());int n3 = n1 + n2;num3.setText("" + n3);}}

import java.awt.*;import java.awt.event.*;public class TestInnerClass {    public static void main(String[] args) {    new TFFrame().launchFrame();    }}class TFFrame extends Frame {public void launchFrame() {TextField num1 = new TextField(10);TextField num2 = new TextField(10);TextField num3 = new TextField(15);Label lbPlus = new Label("+");Button btnEqual = new Button("=");setLayout(new FlowLayout());add(num1);add(lbPlus);add(num2);add(btnEqual);add(num3);btnEqual.addActionListener(new MyMonitor(this/*num1, num2, num3*/));pack();setVisible(true);}}class MyMonitor implements ActionListener {//TextField num1,num2,num3;//MyMonitor(TextField num1, TextField num2, TextField num3) {//this.num1 = num1;//this.num2 = num2;//this.num3 = num3;//} //持有对方的引用TFFrame tf = null;public MyMonitor(TFFrame tf) {this.tf = tf;}public void actionPerformed(ActionEvent e) {int n1 = Integer.parseInt(tf.num1.getText());int n2 = Integer.parseInt(tf.num2.getText());int n3 = n1 + n2;tf.num3.setText("" + n3);}}

import java.awt.*;import java.awt.event.*;public class TestInnerClass {    public static void main(String[] args) {    new TFFrame().launchFrame();    }}class TFFrame extends Frame {TextField num1, num2, num3;public void launchFrame() {num1 = new TextField(10);num2 = new TextField(10);num3 = new TextField(15);Label lbPlus = new Label("+");Button btnEqual = new Button("=");setLayout(new FlowLayout());add(num1);add(lbPlus);add(num2);add(btnEqual);add(num3);btnEqual.addActionListener(new MyMonitor());pack();setVisible(true);}//内部类:1，方便的访问包装类的成员//       2，该类不允许或不需要其他类进行访问class MyMonitor implements ActionListener {public void actionPerformed(ActionEvent e) {int n1 = Integer.parseInt(num1.getText());int n2 = Integer.parseInt(num2.getText());int n3 = n1 + n2;num3.setText("" + n3);}}}