java代码---------计算器实现

总结：虽然，没有人会帮你到底，凭什么要对你怜香惜玉

注意实现哪一个运算就把相关代码放在else if这个判断语句里面

package com.rue;

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;

//实现计算器的功能，我他妈的真是不懂变通。

class Ji extends JFrame implements ActionListener {
	private static final String CE = null;
	// 定义按钮
	StringBuffer str = new StringBuffer();
	JButton jb_0, jb_1, jb_2, jb_3, jb_4, jb_5, jb_6, jb_7, jb_8, jb_9, jb_jia,
			jb_jian, jb_cheng, jb_chu, jb_dian, jb_deng, jb_delete;
	JLabel jf;
	double num1 = 0;
	double num2 = 0;
	char c = '\0';
	double m;
	boolean ready = true;

	public Ji() {
		JPanel jp = new JPanel(new GridLayout(5, 4));// 把所有的按钮组件和文本框放在这个panel里面
		jf = new JLabel("0.0");
		jf.setFont(new Font("", 1, 18));
		jf.setHorizontalAlignment(JLabel.RIGHT);
		jb_delete = new JButton("CE");// 设一个删除的按钮
		jb_0 = new JButton("0");
		JButton jb_genghao = new JButton("√");
		jb_1 = new JButton("1");
		jb_genghao.addActionListener(this);
		jb_2 = new JButton("2");
		jb_3 = new JButton("3");
		jb_4 = new JButton("4");
		jb_5 = new JButton("5");
		jb_6 = new JButton("6");
		jb_7 = new JButton("7");
		jb_8 = new JButton("8");
		jb_9 = new JButton("9");
		jb_jia = new JButton("+");
		jb_jian = new JButton("-");
		jb_cheng = new JButton("*");
		jb_chu = new JButton("/");
		jb_dian = new JButton(".");
		jb_deng = new JButton("=");
		//
		jb_delete.addActionListener(this);
		jb_0.addActionListener(this);
		jb_1.addActionListener(this);
		jb_2.addActionListener(this);
		jb_3.addActionListener(this);
		jb_4.addActionListener(this);
		jb_5.addActionListener(this);
		jb_6.addActionListener(this);
		jb_7.addActionListener(this);
		jb_8.addActionListener(this);
		jb_9.addActionListener(this);
		jb_jia.addActionListener(this);
		jb_jian.addActionListener(this);
		jb_cheng.addActionListener(this);
		jb_chu.addActionListener(this);
		jb_dian.addActionListener(this);
		jb_deng.addActionListener(this);

		JButton jb_Back = new JButton("Back");
		jb_Back.addActionListener(this);

		jp.add(jb_1);
		jp.add(jb_2);
		jp.add(jb_3);
		jp.add(jb_4);
		jp.add(jb_5);
		jp.add(jb_6);
		jp.add(jb_7);
		jp.add(jb_8);
		// this.add(jp);

		jp.add(jb_9);

		jp.add(jb_jia);
		jp.add(jb_jian);
		jp.add(jb_cheng);
		jp.add(jb_chu);
		jp.add(jb_dian);
		jp.add(jb_deng);
		jp.add(jb_0);
		jp.add(jb_Back);
		jp.add(jb_delete);
		jp.add(jb_genghao);
		this.add(jf, BorderLayout.NORTH);
		this.add(jp);

		// this.setLayout();
		this.setVisible(true);

		this.setBounds(100, 20, 230, 300);
		this.setDefaultCloseOperation(3);

	}

	public double count() {
		switch (c) {
		case '+':
			m = num1 + num2;
			break;
		case '-':
			m = num1 - num2;
			break;
		case '*':
			m = num1 * num2;
			break;
		case '/':
			m = num1 / num2;
			break;
		case '√':
			m = Math.sqrt(num1);
			break;
		case 'E':
			m = '\0';
		}

		return m;
	}

	public void actionPerformed(ActionEvent e) {
		String str = e.getActionCommand();
		if (str.equals("0") || str.equals(".") || str.equals("1")
				|| str.equals("2") || str.equals("3") || str.equals("4")
				|| str.equals("5") || str.equals("6") || str.equals("7")
				|| str.equals("8") || str.equals("9") || str.equals("1")) {
			if (ready) {
				jf.setText(str);
				ready = false;
			} else {

				jf.setText(jf.getText() + str);
				ready = false;
			}

		} else if (str.equals("+")) {
			num1 = Double.parseDouble(jf.getText());
			// count();
			// ////////////其实可以感觉到操作符有点不正常的。就是操作符设置的问题有点大
			// if(num1=){}
			c = '+';

			ready = true;
		} else if (str.equals("√")) {
			num1 = Double.parseDouble(jf.getText());
			c = '√';
			ready = true;
		} else if (str.equals("CE")) {
			num1 = Double.parseDouble(jf.getText());
			// c='c';//这里可以判断按的是哪一个按钮吗？
			jf.setText("0.0");// 记住这里是要清空，但并不是把lable也全部删除看不见。Label的作用。
			ready = true;// 当这里为false时，它会与0.0连接一起显示出来，此时设置我ture。它正常了。是不是继续执行下一步的意思呢？

		} else if (str.equals("-")) {
			num1 = Double.parseDouble(jf.getText());
			c = '-';
			ready = true;
		} else if (str.equals("*")) {
			num1 = Double.parseDouble(jf.getText());
			c = '*';
			ready = true;
		} else if (str.equals("/")) {
			num1 = Double.parseDouble(jf.getText());
			c = '/';
			ready = true;
		} else if (str.equals("=")) {
			num2 = Double.parseDouble(jf.getText());

			jf.setText(count() + "");

			ready = false;
		}

	}

}

public class Test {
	public static void main(String[] args) {
		new Ji();
	}
}