java设计一个简单计算器
//最简单的，效果如图
优化版的在这里
优化之后的java计算器
这是简单计算器的代码：
package count;
import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.Font;
import javax.swing.SwingConstants;
public class Calculator extends JFrame {
private JPanel contentPane;
private JTextField textField;
private int operator = 0;
String num1 = "", num2 = "";
private double number1, number2;
private boolean flag = false;
double value;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Calculator frame = new Calculator();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public Calculator() {
setTitle("\u8BA1\u7B97\u5668");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 418, 388);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);
textField = new JTextField();
textField.setFont(new Font("宋体", Font.BOLD, 30));
textField.setText("0");
textField.setHorizontalAlignment(SwingConstants.RIGHT);
textField.setBounds(14, 24, 372, 59);
contentPane.add(textField);
textField.setColumns(10);
//数字部分
JButton btn0 = new JButton("0");
btn0.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (flag) {
textField.setText("0");
flag = false;
} else {
if (textField.getText().equals("0")) {
textField.setText("0");
} else
textField.setText(textField.getText() + 0);
}
}
});
btn0.setFont(new Font("黑体", Font.BOLD, 15));
btn0.setBounds(14, 260, 53, 43);
contentPane.add(btn0);
JButton btn1 = new JButton("1");
btn1.setFont(new Font("黑体", Font.BOLD, 15));
btn1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (flag) {
textField.setText("1");
flag = false;
} else {
if (textField.getText().equals("0"))
textField.setText("1");
else
textField.setText(textField.getText() + 1);
}
}
});
btn1.setBounds(14, 92, 53, 43);
contentPane.add(btn1);
JButton btn2 = new JButton("2");
btn2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (flag) {
textField.setText("2");
flag = false;
} else {
if (textField.getText().equals("0"))
textField.setText("2");
else
textField.setText(textField.getText() + 2);
}
}
});
btn2.setFont(new Font("黑体", Font.BOLD, 15));
btn2.setBounds(81, 92, 53, 43);
contentPane.add(btn2);
JButton btn3 = new JButton("3");
btn3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (flag) {
textField.setText("3");
flag = false;
} else {
if (textField.getText().equals("0"))
textField.setText("3");
else
textField.setText(textField.getText() + 3);
}
}
});
btn3.setFont(new Font("黑体", Font.BOLD, 15));
btn3.setBounds(148, 92, 53, 43);
contentPane.add(btn3);
JButton btn4 = new JButton("4");
btn4.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (flag) {
textField.setText("4");
flag = false;
} else {
if (textField.getText().equals("0"))
textField.setText("4");
else
textField.setText(textField.getText() + 4);
}
}
});
btn4.setFont(new Font("黑体", Font.BOLD, 15));
btn4.setBounds(14, 148, 53, 43);
contentPane.add(btn4);
JButton btn5 = new JButton("5");
btn5.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (flag) {
textField.setText("5");
flag = false;
} else {
if (textField.getText().equals("0"))
textField.setText("5");
else
textField.setText(textField.getText() + 5);
}
}
});
btn5.setFont(new Font("黑体", Font.BOLD, 15));
btn5.setBounds(81, 148, 53, 43);
contentPane.add(btn5);
JButton btn6 = new JButton("6");
btn6.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (flag) {
textField.setText("6");
flag = false;
} else {
if (textField.getText().equals("0"))
textField.setText("6");
else
textField.setText(textField.getText() + 6);
}
}
});
btn6.setFont(new Font("黑体", Font.BOLD, 15));
btn6.setBounds(148, 148, 53, 43);
contentPane.add(btn6);
JButton btn7 = new JButton("7");
btn7.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (flag) {
textField.setText("7");
flag = false;
} else {
if (textField.getText().equals("0"))
textField.setText("7");
else
textField.setText(textField.getText() + 7);
}
}
});
btn7.setFont(new Font("黑体", Font.BOLD, 15));
btn7.setBounds(14, 204, 53, 43);
contentPane.add(btn7);
JButton btn8 = new JButton("8");
btn8.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (flag) {
textField.setText("8");
flag = false;
} else {
if (textField.getText().equals("0"))
textField.setText("8");
else
textField.setText(textField.getText() + 8);
}
}
});
btn8.setFont(new Font("黑体", Font.BOLD, 15));
btn8.setBounds(81, 204, 53, 43);
contentPane.add(btn8);
JButton btn9 = new JButton("9");
btn9.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (flag) {
textField.setText("9");
flag = false;
} else {
if (textField.getText().equals("0"))
textField.setText("9");
else
textField.setText(textField.getText() + 9);
}
}
});
btn9.setFont(new Font("黑体", Font.BOLD, 15));
btn9.setBounds(148, 204, 53, 43);
contentPane.add(btn9);
// 运算符
JButton btnAdd = new JButton("+");
btnAdd.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
num1 = textField.getText();
operator = 1;
flag = true;
}
});
btnAdd.setFont(new Font("黑体", Font.BOLD, 15));
btnAdd.setBounds(215, 92, 53, 43);
contentPane.add(btnAdd);
JButton btnsubtract = new JButton("-");
btnsubtract.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
num1 = textField.getText();
operator = 2;
flag = true;
}
});
btnsubtract.setFont(new Font("黑体", Font.BOLD, 15));
btnsubtract.setBounds(215, 148, 53, 43);
contentPane.add(btnsubtract);
JButton btnmultiply = new JButton("*");
btnmultiply.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
num1 = textField.getText();
operator = 3;
flag = true;
}
});
btnmultiply.setFont(new Font("黑体", Font.BOLD, 15));
btnmultiply.setBounds(215, 204, 53, 43);
contentPane.add(btnmultiply);
JButton btndivide = new JButton("/");
btndivide.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
num1 = textField.getText();
operator = 4;
flag = true;
}
});
btndivide.setFont(new Font("黑体", Font.BOLD, 15));
btndivide.setBounds(215, 260, 53, 43);
contentPane.add(btndivide);
// 符号部分
JButton btnpoint = new JButton(".");
btnpoint.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (flag) {
textField.setText(".");
flag = false;
} else {
if (textField.getText().equals("0"))
textField.setText("0.");
else
textField.setText(textField.getText() + ".");
}
flag = false;
}
});
btnpoint.setFont(new Font("黑体", Font.BOLD, 15));
btnpoint.setBounds(81, 260, 53, 43);
contentPane.add(btnpoint);
JButton btnC = new JButton("C");
btnC.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
textField.setText("0");
}
});
btnC.setFont(new Font("黑体", Font.BOLD, 15));
btnC.setBounds(148, 260, 53, 43);
contentPane.add(btnC);
JButton btnequal = new JButton("=");
btnequal.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// num1 operator num2 =
number1 = Double.parseDouble(num1);
number2 = Double.parseDouble(textField.getText());
if (operator == 1)
value = number1 + number2;
else if (operator == 2)
value = number1 - number2;
else if (operator == 3)
value = number1 * number2;
else if (operator == 4)
value = number1 / number2;
if ((int) value == value) {
int exp1 = (int) value;
textField.setText(exp1 + "");
} else {
String exp0 = String.valueOf(value);
textField.setText(exp0);
}
}
});
btnequal.setFont(new Font("黑体", Font.PLAIN, 37));
btnequal.setBounds(301, 97, 85, 206);
contentPane.add(btnequal);
}
}
基于windowbuilder设计的。只实现了简单的加减乘除以及复位功能，还存在很多缺点。
缺点有：
*无法进行多个数据的计算（只能准确进行一对数据的计算）
*界面还需要进一步美化。方法并没有进行封装，导致代码量较大。
*计算的数据有大小限制。
*还没有设计当出现错误时跳出的提示信息或窗口。（例如除数不能为0，小数点不能为多个等等）。
后面如果有空闲时间还会继续优化。
我的水平有限，如果有什么错误或者更好的建议希望大家给我留言和发消息，一起共同进步。：）