java程序_计算器.txt

Calculator

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

//计算器显示结果的窗体 
class Result extends JPanel { 
//text先是输入和结果 
JTextField text = new JTextField("0"); 
Result() { 
//讲输入的数字或得到的结果在text的右边显示 
text.setHorizontalAlignment(SwingConstants.RIGHT); 
text.enable(false);//文本框不能编辑 
setLayout(new BorderLayout());//设定布局管理器边框布局 
add(text, BorderLayout.CENTER);//text放置在窗体的中间 
} 
} 

//计算器数字按钮定义面板 
class Number_Key extends JPanel { 
JButton zero = new JButton("0");//数字键0 
JButton one = new JButton("1");//数字键1 
JButton two = new JButton("2");//数字键2 
JButton three = new JButton("3");//数字键3 
JButton four = new JButton("4");//数字键4 
JButton five = new JButton("5");//数字键5 
JButton six = new JButton("6");//数字键6 
JButton seven = new JButton("7");//数字键7 
JButton eight = new JButton("8");//数字键8 
JButton nine = new JButton("9");//数字键9 
JButton plus = new JButton("+"); 
JButton sub = new JButton("-"); 
JButton mul = new JButton("*"); 
JButton div = new JButton("/"); 
JButton equal = new JButton("="); 
JButton ce = new JButton("ce");//置零键 
JButton point = new JButton("."); 
JButton tzero = new JButton("00"); 
Number_Key() { 
setLayout(new GridLayout(6, 3, 10, 10));//定义布局管理器为网格布局 
//添加各个按钮键 
add(seven); 
add(eight); 
add(nine); 
add(four); 
add(five); 
add(six); 
add(one); 
add(two); 
add(three); 
add(zero); 
add(tzero); 
add(plus); 
add(sub); 
add(mul); 
add(div); 
add(point); 
add(equal); 
add(ce); 

} 
} 

//计算器主类 
public class Calculator extends JFrame implements ActionListener { 
Result result = new Result();//定义text的面板 
Number_Key number_key = new Number_Key();//定义按钮面板 
//当点击按钮+、-、*、/时，com = true 
boolean com = false; 
//当i=0时说明是我们第一次输入，字符串sum不会累加 
int i = 0; 
//存放text的内容 
String sum = ""; 
//存放点击按钮+、-、*、/之前的数值 
double total = 0; 
//+、-、*、/的代号分别为1，2，3，4 
int symbol = 0; 
Calculator() { 
super("Calculator");//设定标题 
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//设定关闭窗体时退出程序 
JPanel pane = new JPanel();//定义主面板 
pane.setLayout(new BorderLayout()); 
pane.add(result, BorderLayout.NORTH); 
pane.add(number_key, BorderLayout.SOUTH); 
number_key.one.addActionListener(this);//对1按钮添加监听事件 
number_key.two.addActionListener(this);//对2按钮添加监听事件 
number_key.three.addActionListener(this);//对3按钮添加监听事件 
number_key.four.addActionListener(this);//对4按钮添加监听事件 
number_key.five.addActionListener(this);//对5按钮添加监听事件 
number_key.six.addActionListener(this);//对6按钮添加监听事件 
number_key.seven.addActionListener(this);//对7按钮添加监听事件 
number_key.eight.addActionListener(this);//对8按钮添加监听事件 
number_key.nine.addActionListener(this);//对9按钮添加监听事件 
number_key.zero.addActionListener(this);//对0按钮添加监听事件 
number_key.ce.addActionListener(this);//对置零按钮添加监听事件 
number_key.plus.addActionListener(this);//对+按钮添加监听事件 
number_key.equal.addActionListener(this);//对=按钮添加监听事件 
number_key.sub.addActionListener(this);//对-按钮添加监听事件 
number_key.mul.addActionListener(this);//对*按钮添加监听事件 
number_key.div.addActionListener(this);//对/按钮添加监听事件 
number_key.tzero.addActionListener(this);//对00按钮添加监听事件 
number_key.point.addActionListener(this);//对.按钮添加监听事件 
setContentPane(pane); 
pack();//初始化窗体大小为正好盛放所有按钮 
} 
//各个按钮触发的事件 
public void actionPerformed(ActionEvent e) { 
/*如果是点击数字按钮那么先要判断是否在此之前点击了+、-、*、/、=，如果是那么com=true 
* 如果没有com= false;或者是否点击数字键，如果是i = 1,如果没有 i = 0; 
**/ 
if (e.getSource() == number_key.one) { 
if (com || i == 0) { 
result.text.setText("1"); 
com = false; 
i = 1; 
} else { 
sum = result.text.getText(); 
result.text.setText(sum + "1"); 
} 
} else if (e.getSource() == number_key.two) { 
if (com || i == 0) { 
result.text.setText("2"); 
com = false; 
i = 1; 
} else { 
sum = result.text.getText(); 
result.text.setText(sum + "2"); 
} 

} else if (e.getSource() == number_key.three) { 
if (com || i == 0) { 
result.text.setText("3"); 
com = false; 
i = 1; 
} else { 
sum = result.text.getText(); 
result.text.setText(sum + "3"); 
} 
} else if (e.getSource() == number_key.four) { 
if (com || i == 0) { 
result.text.setText("4"); 
com = false; 
i = 1; 
} else { 
sum = result.text.getText(); 
result.text.setText(sum + "4"); 
} 
} else if (e.getSource() == number_key.five) { 
if (com || i == 0) { 
result.text.setText("5"); 
com = false; 
i = 1; 
} else { 
sum = result.text.getText(); 
result.text.setText(sum + "5"); 
} 
} else if (e.getSource() == number_key.six) { 
if (com || i == 0) { 
result.text.setText("6"); 
com = false; 
i = 1; 
} else { 
sum = result.text.getText(); 
result.text.setText(sum + "6"); 
} 
} else if (e.getSource() == number_key.seven) { 
if (com || i == 0) { 
result.text.setText("7"); 
com = false; 
i = 1; 
} else { 
sum = result.text.getText(); 
result.text.setText(sum + "7"); 
} 
} else if (e.getSource() == number_key.eight) { 
if (com || i == 0) { 
result.text.setText("8"); 
com = false; 
i = 1; 
} else { 
sum = result.text.getText(); 
result.text.setText(sum + "8"); 
} 
} else if (e.getSource() == number_key.nine) { 
if (com || i == 0) { 
result.text.setText("9"); 
com = false; 
i = 1; 
} else { 
sum = result.text.getText(); 
result.text.setText(sum + "9"); 
} 
} 
/*对于0这个按钮有一定的说法，在我的程序里不会出现如00000这样的情况，我加了判断条件就是 
* 如果text中的数值=0就要判断在这个数值中是否有.存在?如果有那么就在原来数值基础之上添 
* 加0;否则保持原来的数值不变 
*/ 
else if (e.getSource() == number_key.zero) { 
if (com || i == 0) { 
result.text.setText("0"); 
com = false; 
i = 1; 
} else { 
sum = result.text.getText(); 
if (Float.parseFloat(sum) > 0 || Float.parseFloat(sum) < 0) { 
result.text.setText(sum + "0"); 
} else { 
if (sum.trim().indexOf(".") == -1) { 
result.text.setText(sum); 
} else { 
result.text.setText(sum + "0"); 
} 
} 
} 
} else if (e.getSource() == number_key.ce) { 
result.text.setText("0"); 
i = 0; 
com = true; 
} else if (e.getSource() == number_key.tzero) { 
if (com || i == 0) { 
result.text.setText("0"); 
com = false; 
i = 1; 
} else { 
sum = result.text.getText(); 
if (Float.parseFloat(sum) > 0 || Float.parseFloat(sum) < 0) { 
result.text.setText(sum + "00"); 
} else { 
if (sum.trim().indexOf(".") == -1) { 
result.text.setText(sum); 
} else { 
result.text.setText(sum + "00"); 
} 
} 
} 
} 
/*本程序不会让一个数值中出现2个以上的小数点.具体做法是:判断是否已经存在.存在就不添加, 
* 不存在就添加. 
*/ 
else if (e.getSource() == number_key.point) { 
if (com || i == 0) { 
result.text.setText("0."); 
com = false; 
i = 1; 
} else { 
sum = result.text.getText(); 
if (sum.trim().indexOf(".") == -1) { 
result.text.setText(sum + "."); 
} else { 
result.text.setText(sum); 
} 

} 
}//获得点击+之前的数值 
else if (e.getSource() == number_key.plus) { 
com = true; 
i = 0; 
total = Double.parseDouble(result.text.getText()); 
symbol = 1; 
}//获得点击-之前的数值 
else if (e.getSource() == number_key.sub) { 
com = true; 
i = 0; 
total = Double.parseDouble(result.text.getText()); 

symbol = 2; 
}//获得点击*之前的数值 
else if (e.getSource() == number_key.mul) { 
com = true; 
i = 0; 
total = Double.parseDouble(result.text.getText()); 
System.out.println(total); 
symbol = 3; 
}//获得点击/之前的数值 
else if (e.getSource() == number_key.div) { 
com = true; 
i = 0; 
total = Double.parseDouble(result.text.getText()); 
symbol = 4; 
} else if (e.getSource() == number_key.equal) { 
switch (symbol) { 
case 1 ://计算加法 
{ 
double ad = 
total + Double.parseDouble(result.text.getText()); 
result.text.setText(ad + ""); 
i = 0; 
sum = ""; 
break; 
} 
case 2 ://计算减法 
{ 
double ad = 
total - Double.parseDouble(result.text.getText()); 
result.text.setText(String.valueOf(ad)); 
i = 0; 
sum = ""; 
break; 
} 
case 3 ://计算乘法 
{ 
double ad = 
total * Double.parseDouble(result.text.getText()); 

result.text.setText(ad + ""); 
i = 0; 
sum = ""; 
break; 
} 
case 4 ://计算除法 
{ 
double ad = 
total / Double.parseDouble(result.text.getText()); 
result.text.setText(ad + ""); 
i = 0; 
sum = ""; 
break; 
} 
} 
System.out.println(com); 
} 
} 
public static void main(String[] args) { 
Calculator ww = new Calculator(); 
ww.show(); 
} 
}