java编译计算器
这个计算器的界面模仿Windows自带的简易计算器。
思路：
不考虑连续计算(如1+2+1)的情况，只是两个数值进行基本运算
1、定义三个变量
2、将第一次按钮的值赋值个第一个变量
3、将第二个按钮的值(也就是加减乘除)赋值给第二个变量
4、将第三个按钮的值赋值给第三个变量
5、用case或者if判断第二个变量，判断是那种计算，比如是+,就直接将第一个和第三个变量相加
6、将得到的结果显示
代码：
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
public class Jisuanqi extends JFrame implements ActionListener {
/**
*
*/
private static final long serialVersionUID = 1L;
Result result = new Result(); /pic/p>
Number_Key number_key = new Number_Key(); /pic/p>
/pic/时，com = true
boolean com = false;
/pic/p>
int i = 0;
/pic/p>
String text = "";
/pic/之前的数值
double defbutton = 0;
/pic/的代号分别为1，2，3，4
int symbol = 0;
/pic/p>
Jisuanqi() {
super("WangJiao"); /pic/p>
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); /pic/p>
JPanel pane = new JPanel(); /pic/p>
pane.setLayout(new BorderLayout());
setBounds(380, 220, 30, 80); /pic/p>
/pic/p>
ImageIcon icon = new ImageIcon("F:1.GIF");
/pic/p>
/pic/p>
setIconImage(icon.getImage());
pane.add(result, BorderLayout.NORTH);
pane.add(number_key, BorderLayout.CENTER);
pane.add(number_key.equal, BorderLayout.SOUTH);
number_key.one.addActionListener(this); /pic/p>
number_key.two.addActionListener(this); /pic/p>
number_key.three.addActionListener(this); /pic/p>
number_key.four.addActionListener(this); /pic/p>
number_key.five.addActionListener(this); /pic/p>
number_key.six.addActionListener(this); /pic/p>
number_key.seven.addActionListener(this); /pic/p>
number_key.eight.addActionListener(this); /pic/p>
number_key.nine.addActionListener(this); /pic/p>
number_key.zero.addActionListener(this); /pic/p>
number_key.ce.addActionListener(this); /pic/p>
number_key.plus.addActionListener(this); /pic/p>
number_key.equal.addActionListener(this); /pic/p>
number_key.sub.addActionListener(this); /pic/p>
number_key.mul.addActionListener(this); /pic/p>
number_key.div.addActionListener(this); /pic/按钮添加监听事件
number_key.point.addActionListener(this); /pic/p>
setContentPane(pane);
pack(); /pic/p>
}
/pic/p>
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 {
text = result.text.getText();
result.text.setText(text + "1");
}
} else if (e.getSource() == number_key.two) {
if (com || i == 0) {
result.text.setText("2");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "2");
}
} else if (e.getSource() == number_key.three) {
if (com || i == 0) {
result.text.setText("3");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "3");
}
} else if (e.getSource() == number_key.four) {
if (com || i == 0) {
result.text.setText("4");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "4");
}
} else if (e.getSource() == number_key.five) {
if (com || i == 0) {
result.text.setText("5");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "5");
}
} else if (e.getSource() == number_key.six) {
if (com || i == 0) {
result.text.setText("6");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "6");
}
} else if (e.getSource() == number_key.seven) {
if (com || i == 0) {
result.text.setText("7");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "7");
}
} else if (e.getSource() == number_key.eight) {
if (com || i == 0) {
result.text.setText("8");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "8");
}
} else if (e.getSource() == number_key.nine) {
if (com || i == 0) {
result.text.setText("9");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "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) { /pic/p>
if (com || i == 0) {
result.text.setText("0");
com = false;
i = 1;
} else {
text = result.text.getText();
if (Float.parseFloat(text) > 0 || Float.parseFloat(text) < 0) { /pic/p>
result.text.setText(text + "0");
} else {
if (text.trim().indexOf(".") == -1) {
result.text.setText(text);
} else {
result.text.setText(text + "0");
}
}
}
} else if (e.getSource() == number_key.ce) {
result.text.setText("0");
i = 0;
com = true;
/pic/p>
defbutton = 0;
}
/*
* 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 {
text = result.text.getText();
if (text.trim().indexOf(".") == -1) {
result.text.setText(text + ".");
} else {
result.text.setText(text);
}
}
} /pic/p>
else if (e.getSource() == number_key.plus) {
com = true;
i = 0;
defbutton = Double.parseDouble(result.text.getText());
symbol = 1;
} /pic/p>
else if (e.getSource() == number_key.sub) {
com = true;
i = 0;
defbutton = Double.parseDouble(result.text.getText());
symbol = 2;
} /pic/p>
else if (e.getSource() == number_key.mul) {
com = true;
i = 0;
defbutton = Double.parseDouble(result.text.getText());
System.out.println(defbutton);
symbol = 3;
} /pic/之前的数值
else if (e.getSource() == number_key.div) {
com = true;
i = 0;
defbutton = Double.parseDouble(result.text.getText());
symbol = 4;
} else if (e.getSource() == number_key.equal) {
switch (symbol) {
case 1: { /pic/p>
double ad = defbutton
+ Double.parseDouble(result.text.getText());
result.text.setText(ad + "");
i = 0;
text = "";
break;
}
case 2: { /pic/p>
double ad = defbutton
- Double.parseDouble(result.text.getText());
result.text.setText(String.valueOf(ad));
i = 0;
text = "";
break;
}
case 3: { /pic/p>
double ad = defbutton
* Double.parseDouble(result.text.getText());
result.text.setText(ad + "");
i = 0;
text = "";
break;
}
case 4: { /pic/p>
double ad = defbutton
/ Double.parseDouble(result.text.getText());
result.text.setText(ad + "");
i = 0;
text = "";
break;
}
}
System.out.println(com);
}
System.out.println(result.text.getText());
}
@SuppressWarnings("deprecation")
public static void main(String[] args) {
Jisuanqi loveyou = new Jisuanqi();
loveyou.show();
}
}
/pic/p>
class Number_Key extends JPanel {
/**
*
*/
private static final long serialVersionUID = 1L;
JButton zero = new JButton("0"); /pic/p>
JButton one = new JButton("1"); /pic/p>
JButton two = new JButton("2"); /pic/p>
JButton three = new JButton("3"); /pic/p>
JButton four = new JButton("4"); /pic/p>
JButton five = new JButton("5"); /pic/p>
JButton six = new JButton("6"); /pic/p>
JButton seven = new JButton("7"); /pic/p>
JButton eight = new JButton("8"); /pic/p>
JButton nine = new JButton("9"); /pic/p>
JButton plus = new JButton("+");
JButton sub = new JButton("-");
JButton mul = new JButton("*");
JButton div = new JButton("/");
JButton equal = new JButton("=");
JButton ce = new JButton("清零"); /pic/p>
JButton point = new JButton(".");
Number_Key() {
setLayout(new GridLayout(4, 4, 1, 1)); /pic/p>
setBackground(Color.blue); /pic/p>
/pic/p>
add(one);
add(two);
add(three);
add(four);
add(five);
add(six);
add(seven);
add(eight);
add(nine);
add(zero);
add(plus);
add(sub);
add(mul);
add(div);
add(point);
add(equal);
add(ce);
}
}
/pic/p>
class Result extends JPanel {
/**
*
*/
private static final long serialVersionUID = 1L;
/pic/p>
JTextField text = new JTextField("0");
@SuppressWarnings("deprecation")
Result() { /pic/p>
text.setHorizontalAlignment(SwingConstants.RIGHT);
text.enable(false); /pic/p>
setLayout(new BorderLayout()); /pic/p>
add(text, BorderLayout.CENTER); /pic/p>
}
}
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