java实现简单计算器

设计一个简单的计算器，包括界面布局、属性设置和事件代码

• 计算器提供简单的加减乘除运算
• 按照需要加入控件，并按照一定的要求进行布局，要求界面美观
• 为按钮、窗口添加事件，完成数字的输入和结果计算
• 处理输出异常，如输入字符或者无输出。

import java.awt.event.*;
import javax.swing.*;

public class T extends Jframe implements ActionListener {
	JLabel title;
	Jtextarea result;
	JTextField tf1, tf2;
	JComboBox sy;
	JButton cal, cal2;
	JPanel jP;

	public T(String s) {
		super(s);
		this.setSize(400, 300);
		this.setLocation(600, 300);
		this.init();
	}

	public void init() {
		title = new JLabel("计算器", 0);
		result = new Jtextarea();
		tf1 = new JTextField(5);
		tf2 = new JTextField(5);

		// tf1.addKeyListener(new KeyAdapter() {
		// public void keyPressed(KeyEvent e) {
		// char keychar = e.getKeyChar();
		// int keycode = e.getKeyCode();
		// System.out.println("字符->" + keychar + "代码-->" + keycode);
		// }
		// });

		sy = new JComboBox();
		sy.addItem("+");
		sy.addItem("-");
		sy.addItem("*");
		sy.addItem("/");
		sy.addItem("%");

		cal = new JButton("计算");
		cal2 = new JButton("clear");

		cal.addActionListener(this);
		cal2.addActionListener(this);
		jP = new JPanel();
		jP.add(tf1);
		jP.add(sy);
		jP.add(tf2);
		jP.add(cal);
		jP.add(cal2);
		this.add("North", title);
		this.add("Center", result);
		this.add("South", jP);

	}

	public void actionPerformed(ActionEvent e1) {
		try {
			double c1 = Double.parseDouble(tf1.getText().toString());
			double c2 = Double.parseDouble(tf2.getText().toString());
			double c = 0;
			boolean flag = true;
			if (e1.getActionCommand() == "计算") {
				if (sy.getSelectedItem() == "+")
					c = c1 + c2;
				else if (sy.getSelectedItem() == "-")
					c = c1 - c2;
				else if (sy.getSelectedItem() == "*")
					c = c1 * c2;
				else if (sy.getSelectedItem() == "/") {
					if (c2 != 0)
						c = c1 / c2;
					else
						flag = false;
				} else if (sy.getSelectedItem() == "%")
					c = c1 % c2;
				if (flag)
					result.insert(tf1.getText() + sy.getSelectedItem() + tf2.getText() + "=" + c + "n", 0);
				else
					result.insert("0不能被整除" + "n", 0);
			}
		} catch (Exception e) {
			result.insert("输入的值有误" + "n", 0);
		}

		if (e1.getActionCommand() == "clear") {
			result.setText("");
		}
	}

	public static void main(String[] args) {

		T xiao = new T("xiaoxiaoran");
		xiao.setVisible(true);
		xiao.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent arg0) {
				System.exit(0);
			}
		});

	}

}