tfmath.java

简单实现键盘的控制

package com.zhoutenghn;

import java.awt.*;
import java.awt.event.*;

public class TFmath {

	public static void main(String[] args) {
		new TFrame().launch();
	}

}

class TFrame extends Frame {
	TextField num1, num2, num3;

	public void launch() {
		num1 = new TextField(10);
		num2 = new TextField(10);
		num3 = new TextField(15);
		Label add = new Label("+");
		Button equel = new Button("=");
		equel.addActionListener(new Moniter());
		setLayout(new FlowLayout());
		add(num1);
		add(add);
		add(num2);
		add(equel);
		add(num3);
		pack();
		setVisible(true);
	}

	private class Moniter implements ActionListener {// 内部类！！！
		// 可以直接调用外面包装类的成员变量,如果时私有的话，
		// 别人不能访问此内部类
		public void actionPerformed(ActionEvent e) {
			int n1 = Integer.parseInt(num1.getText());
			int n2 = Integer.parseInt(num2.getText());
			num3.setText("" + (n1 + n2));
			// System.out.println("ok");
		}
	}
}

/*
 * class Moniter implements ActionListener { TFrame tf = null;
 * 
 * public Moniter(TFrame tf) {//此为持有对象的引用，把TFrame对象的引用调过来，以便使用其成员变量 this.tf =
 * tf; }
 * 
 * public void actionPerformed(ActionEvent e) { int n1 =
 * Integer.parseInt(tf.num1.getText()); int n2 =
 * Integer.parseInt(tf.num2.getText()); tf.num3.setText("" + (n1 + n2)); //
 * System.out.println("ok"); }
 *  }
 */