用java编写的简易计算器

使用布局管理器编写的简易计算器。

代码如下：

package com.cjg.jisuanqi;

import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Color;
import java.awt.Frame;
import java.awt.GridLayout;
import java.awt.Panel;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class Calculator extends WindowAdapter {

	Panel p1 = new Panel();
	Panel p2 = new Panel();
	Panel p3 = new Panel();
	TextField txt;
	private Button[] b = new Button[17];
	private String ss[] = {"7","8","9","+","4","5","6","-","1","2","3","*","清空","0","=","/","关闭"};
	static double a = 0;
	static String s, str;
	
	public static void main(String[] args) {
		// TODO 自动生成的方法存根
		(new Calculator()).frame();

	}
	public void frame(){
		Frame fm = new Frame("计算器");
		for (int i = 0; i <=16; i++) {
			b[i] = new Button(ss[i]);
		}
		for (int i = 0; i <=15; i++) {
			p2.add(b[i]);
		}
		b[16].setBackground(Color.yellow);
		
		txt = new TextField(15);
		txt.setEditable(false);
		for (int i = 0; i < 16; i++) {
			b[i].addActionListener(new buttonlistener());
		}
		b[16].addActionListener(new close());
		fm.addWindowListener(this);
		fm.setBackground(Color.red);
		p1.setLayout(new BorderLayout());
		p1.add(txt, "North");
		p2.setLayout(new GridLayout(4,4));
		p3.setLayout(new BorderLayout());
		p3.add(b[16]);
		//添加各个面板到窗口上
		fm.add(p1, "North");
		fm.add(p2, "Center");
		fm.add(p3, "South");
		fm.pack();
		fm.setVisible(true);
	}
	public void windowClosing(WindowEvent e){
		System.exit(0);
	}
	//编写事件监听器
	class buttonlistener implements ActionListener{
		public void actionPerformed(ActionEvent e){
			Button btn = (Button) e.getSource();
			if (btn.getLabel() == "=") {
				jisuan();
				str = String.valueOf(a);
				txt.setText(str);
				s = "";
			} else if(btn.getLabel() == "+") {
				
				jisuan();
				str = String.valueOf(a);
				txt.setText(str);
				//txt.setText("");
				s = "+";
			}else if(btn.getLabel() == "-") {
				
				jisuan();
				str = String.valueOf(a);
				txt.setText(str);
				s = "-";
			}else if(btn.getLabel() == "*") {
				
				jisuan();
				str = String.valueOf(a);
				txt.setText(str);
				s = "*";
			}else if(btn.getLabel() == "/") {
				
				jisuan();
				str = String.valueOf(a);
				txt.setText(str);
				s = "/";
			}else  {
				
				//str = String.valueOf(a);
				txt.setText(btn.getLabel());
				//jisuan();
			}
		}
		public void jisuan(){
			if(s == "+")
				a += Double.parseDouble(txt.getText());
			else if(s == "-")
				a -= Double.parseDouble(txt.getText());
			else if(s == "*")
				a *= Double.parseDouble(txt.getText());
			else if(s == "/")
				a /= Double.parseDouble(txt.getText());
			else 
				a = Double.parseDouble(txt.getText());
		}
	}

}
class close implements ActionListener{
	public void actionPerformed(ActionEvent e){
		System.exit(0);
	}
}