java - 在 GUI 中合计金额

Question

我下面的代码可以完成我想要的一切，除了缺少一个关键功能。我希望它获取每个方 block 的值并将其显示在输入框中。然后，当用户按下总计时，它会显示最终价格加上 7% 的税。目前这只是一个错误，但之前它只是将金额放入总计框中，而没有实际将其相加。我怎样才能让它正确地添加它们？谢谢你!这是我的 2 个类文件:

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
public class PizzaOrder
{

    private JPanel phone;

    public static void main (String[] args)
    {

    JFrame frame = new JFrame ("Pizza Order");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel phone = new JPanel();
    phone.setBorder (BorderFactory.createRaisedBevelBorder());

    JTabbedPane tp = new JTabbedPane();
    tp.addTab ("Pizza Order", new PizzaGUI());

    frame.getContentPane().add(phone);
    frame.getContentPane().add(tp);
    frame.pack();
    frame.pack();frame.setVisible(true);

    }
}


import java.awt.*;
import java.awt.event.*;

import javax.swing.*;


public class PizzaGUI extends JPanel
{
    private JLabel  resultLabel;


    private JButton button0, button1, button2, button3, button4, button5, button6, button7, button8, button9, buttonclear;

    public  PizzaGUI()
    {
        // grid layout
        setLayout (new GridLayout (5, 3));

        // creates buttons  and label
        resultLabel = new JLabel (" ");
        button0 = new JButton ("Small: 10.00");
        button1 = new JButton ("Medium: 14.00");
        button2 = new JButton ("Large: 16.00");
        button3 = new JButton ("Soda: 2.00");
        button4 = new JButton ("Water: 1.50");
        button5 = new JButton ("Extra Cheese: 1.50");
        button6 = new JButton ("Pepperoni: 1.50");
        button7 = new JButton ("Mushroom: 1.50");
        button8 = new JButton ("Sausage: 1.50");
        button9 = new JButton ("Pepper Onion: 1.50");
        buttonclear = new JButton ("Total");

        //listeners for each button
        button0.addActionListener (new ButtonListener0());
        button1.addActionListener (new ButtonListener1());
        button2.addActionListener (new ButtonListener2());
        button3.addActionListener (new ButtonListener3());
        button4.addActionListener (new ButtonListener4());
        button5.addActionListener (new ButtonListener5());
        button6.addActionListener (new ButtonListener6());
        button7.addActionListener (new ButtonListener7());
        button8.addActionListener (new ButtonListener8());
        button9.addActionListener (new ButtonListener9());
        buttonclear.addActionListener(new ButtonListenerT());

        //adds all buttons and label
        add (resultLabel);
        add (button0);
        add (button1);
        add (button2);
        add (button3);
        add (button4);
        add (button5);
        add (button6);
        add (button7);
        add (button8);
        add (button9);
        add (buttonclear);


        setPreferredSize (new Dimension(720,360));
        setBackground (Color.white);
    }

    //code below is one listener per button
    private class ButtonListener0 implements ActionListener
    {
        public void actionPerformed (ActionEvent event)
        {


            resultLabel.setText(resultLabel.getText() + "10.00");
        }
    }


    private class ButtonListener1 implements ActionListener
    {
        public void actionPerformed (ActionEvent event)
        {



            resultLabel.setText(resultLabel.getText() + "14.00");
        }
    }

    private class ButtonListener2 implements ActionListener
    {
        public void actionPerformed (ActionEvent event)
        {


            resultLabel.setText(resultLabel.getText() + "16.00");       
        }
    }


    private class ButtonListener3 implements ActionListener
    {
        public void actionPerformed (ActionEvent event)
        {


            resultLabel.setText(resultLabel.getText() + "2.00");        
        }
    }

    private class ButtonListener4 implements ActionListener
    {
        public void actionPerformed (ActionEvent event)
        {


            resultLabel.setText(resultLabel.getText() + "1.50");         
        }
    }

    private class ButtonListener5 implements ActionListener
    {
        public void actionPerformed (ActionEvent event)
        {


            resultLabel.setText(resultLabel.getText() + "1.50");        
        }
    }

    private class ButtonListener6 implements ActionListener
    {
        public void actionPerformed (ActionEvent event)
        {


            resultLabel.setText(resultLabel.getText() + "1.50");         
        }
    }

    private class ButtonListener7 implements ActionListener
    {
        public void actionPerformed (ActionEvent event)
        {


            resultLabel.setText(resultLabel.getText() + "1.50");         
        }
    }

    private class ButtonListener8 implements ActionListener
    {
        public void actionPerformed (ActionEvent event)
        {


            resultLabel.setText(resultLabel.getText() + "1.50");        
        }
    }

    private class ButtonListener9 implements ActionListener
    {
        public void actionPerformed (ActionEvent event)
        {


            resultLabel.setText(resultLabel.getText() + "1.50");      
        }
    }

    private class ButtonListenerT implements ActionListener
    {
        public void actionPerformed (ActionEvent event)
        {



            double total;

            resultLabel.setText ("Total plus tax:" + total = total *1.07);           
        }
    }


}

Answer 1

好吧，OP 的代码非常模糊且难以理解。所以我要在黑暗中扔一 block 石头。

在除 ButtonListenerT 之外的每个按钮列表器的 actionPerformed 方法中，将代码更改为

private class ButtonListener0 implements ActionListener
{
    public void actionPerformed (ActionEvent event)
    {
        resultLabel.setText(String.valueOf(Double.parseDouble(resultLabel.getText()) + 10.00));        
    }
}

对于 ButtonListener2 10.00 将是 16.00 依此类推...

现在

private class ButtonListenerT implements ActionListener
{
    public void actionPerformed (ActionEvent event)
    {
        double total;
        total = Double.parseDouble(resultLabel.getText());
        resultLabel.setText ("Total plus tax: " + (total *1.07));           
    }
}