javaGUI创建一个窗口实现四则运算_列表框gui四则运算编程java

创建一个窗口实现四则运算

图片

import com.sun.imageio.plugins.gif.GIFImageReader;
import jdk.nashorn.internal.scripts.JO;

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

public class fourArithmetic extends JFrame {
    public fourArithmetic(){
        this.setSize(400,200);
//        this.setLocation(100,100);
        this.setLocationRelativeTo(null);
        this.setTitle("四则运算");
       this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setResizable(false);
        this.setIconImage(new ImageIcon("fourArithmetic.png").getImage());
        this.setLayout(new GridLayout(3,1));

        JPanel jp = new JPanel();
        JPanel jp1 = new JPanel();
        JPanel jp2 = new JPanel();

              JButton jb = new JButton("=");
                      jb.setSize(30,10);

        JTextField num = new JTextField(6);
        JTextField num1 = new JTextField(2);
        JTextField num2 = new JTextField(6);
        JTextField num3 = new JTextField(6);

        jp1.add(num);
        jp1.add(num1);
        jp1.add(num2);
        jp1.add(jb);
        jp1.add(num3);
        this.add(jp);
        this.add(jp1);
        this.add(jp2);
        this.setVisible(true);

        jb.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try{
                    String Num = num.getText();
                    String Num1 = num1.getText();
                    String Num2 = num2.getText();

                    if (Num.length() == 0 || Num1.length() == 0 || Num2.length() == 0) {
                        JOptionPane.showMessageDialog(null, "输入不能为空！", "系统提示", JOptionPane.WARNING_MESSAGE);
                        return;
                    }
                    if (Num.matches("[0-9]+") && Num2.matches("[0-9]+")) {
                        if (Num1.equals("+") || Num1.equals("-") || Num1.equals("*") || Num1.equals("/")) {
                            double a1 = new Double(Num);
                            double a2 = new Double(Num2);
                            if (Num1.equals("+")) {
                                num3.setText("" + (a1 + a2));
                            } else if (Num1.equals("-")) {
                                num3.setText("" + (a1 - a2));
                            } else if (Num1.equals("*")) {
                                num3.setText("" + a1 * a2);
                            } else {
                                num3.setText("" + a1 / a2);
                            }
                        } else {
                            JOptionPane.showMessageDialog(null, "运算符号有误！");
                            return;
                        }

                    } else {
                        JOptionPane.showMessageDialog(null, "请输入数字进行运算！");
                        return;
                    }

                }catch (ArithmeticException e1) {
                    JOptionPane.showMessageDialog(null, "除数不能为0！");
                    return;
                }
            }
        });
    }

    public static void main(String[] args) {
        
        new fourArithmetic();
    }

}

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