我有一个半完整的编码，基本上归结为一个gui界面。问题是我不知道如何让它作为自动售票机工作，固定费率和固定金额的现金可以投入。
所以，到目前为止，我已经做了很多事情来计算我所做的事情的总数，总是得出0.00英镑作为totalamount答案。
我迫切需要帮助。这非常令人沮丧。以下是TicketCalculation类的代码
import java.awt.*;
import java.text.*;
import java.awt.event.*;
import javax.swing.*;
public class TicketCalculation extends JFrame implements ActionListener {
DecimalFormat pounds = new DecimalFormat("£#,##0.00");
//creating and naming buttons and textfields
private JButton twentypenceBtn = new JButton("20p");
private JButton fiftypenceBtn = new JButton("50p");
private JButton onepoundBtn = new JButton("£1");
private JButton twopoundsBtn = new JButton("£2");
private JButton fivepoundsBtn = new JButton("£5");
private JButton tenpoundsBtn = new JButton("£10");
private JButton twentypoundsBtn = new JButton("£20");
private JButton C = new JButton("Calculate");
private JButton frontBtn = new JButton("<<Front Stalls>>");
private JButton private1Btn = new JButton("<<Private Box>>");
private JButton middleBtn = new JButton("<<Middle Stalls>>");
private JButton backBtn = new JButton("<<Back Stalls>>");
private JButton calcBtn = new JButton("Calculate Bill");
private JTextField tickettypeTxt = new JTextField(14);
private JTextField stalltypeTxt = new JTextField(25);
private JTextField amountticketsTxt = new JTextField(14);
private JTextField totalamountTxt = new JTextField(10);
private JTextField amountdueTxt = new JTextField(13);
private JTextField amountpaidTxt = new JTextField(10);
//creating labels
private JLabel pickstall = new JLabel();
private JLabel tictype = new JLabel ();
private JLabel amontic = new JLabel();
private JLabel ttamon = new JLabel();
private JLabel amondue = new JLabel();
private JLabel amonpaid = new JLabel();
private JLabel label5 = new JLabel();
private JLabel spacing6 = new JLabel();
private JLabel spacing7 = new JLabel();
private JLabel spacing8 = new JLabel();
private JLabel spacing9 = new JLabel();
private JLabel spacing10 = new JLabel();
//image icon declarations
private ImageIcon paycount = new ImageIcon(getClass().getResource("paycount.jpg"));
double middleprice;
double privateprice;
double backprice;
double frontprice;
double type;
int number;
public static void main(String[] args){
new TicketCalculation();
}
public TicketCalculationt(){
setLayout(new BorderLayout());
setSize(650,750);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//naming labels
pickstall = new JLabel("==> Pick a Stall Type: ");
tictype = new JLabel ("==> Price of a Ticket: £");
amontic = new JLabel("==> Amount of Tickets: ");
ttamon = new JLabel("==> Total Amount: ");
amondue = new JLabel("==> Amount Due: £");
amonpaid = new JLabel("==> Amount Paid: £");
label5 = new JLabel(paycount);
spacing6 = new JLabel(" ");
spacing7 = new JLabel(" ");
spacing8 = new JLabel(" ");
spacing9 = new JLabel(" ");
spacing10 = new JLabel(" ");
//setting font for buttons, textfields and labels
pickstall.setFont(new Font("Rockwell", Font.BOLD, 20));
frontBtn.setFont(new Font("System", Font.BOLD, 22));
middleBtn.setFont(new Font("System", Font.BOLD, 22));
backBtn.setFont(new Font("System", Font.BOLD, 22));
private1Btn.setFont(new Font("System", Font.BOLD, 22));
tictype.setFont(new Font("Rockwell", Font.BOLD, 20));
amontic.setFont(new Font("Rockwell", Font.BOLD, 20));
ttamon.setFont(new Font("Rockwell", Font.BOLD, 20));
amondue.setFont(new Font("Rockwell", Font.BOLD, 20));
amonpaid.setFont(new Font("Rockwell", Font.BOLD, 20));
stalltypeTxt.setFont(new Font("Verdana", Font.BOLD, 20));
tickettypeTxt.setFont(new Font("Verdana", Font.BOLD, 20));
amountticketsTxt.setFont(new Font("Verdana", Font.BOLD, 20));
totalamountTxt.setFont(new Font("Verdana", Font.BOLD, 20));
amountdueTxt.setFont(new Font("Verdana", Font.BOLD, 20));
amountpaidTxt.setFont(new Font("Verdana", Font.BOLD, 20));
twentypenceBtn.setFont(new Font("Century Gothic", Font.BOLD, 28));
fiftypenceBtn.setFont(new Font("Century Gothic", Font.BOLD, 28));
onepoundBtn.setFont(new Font("Century Gothic", Font.BOLD, 28));
twopoundsBtn.setFont(new Font("Century Gothic", Font.BOLD, 28));
fivepoundsBtn.setFont(new Font("Century Gothic", Font.BOLD, 28));
tenpoundsBtn.setFont(new Font("Century Gothic", Font.BOLD, 28));
twentypoundsBtn.setFont(new Font("Century Gothic", Font.BOLD, 28));
C.setFont(new Font("Serif", Font.BOLD, 28));
stalltypeTxt.setEditable(false);
tickettypeTxt.setEditable(false);
totalamountTxt.setEditable(false);
amountdueTxt.setEditable(false);
amountpaidTxt.setEditable(false);
//positioning all buttons, textfields and labels
JPanel top = new JPanel();
top.add(label5);
add("North", top);
JPanel mid = new JPanel();
mid.add(pickstall);
mid.add(stalltypeTxt);
mid.add(spacing6);
mid.add(private1Btn);
mid.add(frontBtn);
mid.add(middleBtn);
mid.add(backBtn);
mid.add(tictype);
mid.add(tickettypeTxt);
mid.add(spacing7);
mid.add(amontic);
mid.add(amountticketsTxt);
mid.add(spacing8);
mid.add(ttamon);
mid.add(totalamountTxt);
mid.add(calcBtn);
mid.add(spacing10);
mid.add(amonpaid);
mid.add(amountpaidTxt);
mid.add(spacing9);
mid.add(twentypenceBtn);
mid.add(fiftypenceBtn);
mid.add(onepoundBtn);
mid.add(twopoundsBtn);
mid.add(fivepoundsBtn);
mid.add(tenpoundsBtn);
mid.add(twentypoundsBtn);
mid.add(amondue);
mid.add(amountdueTxt);
mid.add(C);
add("Center", mid);
calcBtn.addActionListener(this);
private1Btn.addActionListener(this);
frontBtn.addActionListener(this);
middleBtn.addActionListener(this);
backBtn.addActionListener(this);
twentypenceBtn.addActionListener(this);
fiftypenceBtn.addActionListener(this);
onepoundBtn.addActionListener(this);
twopoundsBtn.addActionListener(this);
fivepoundsBtn.addActionListener(this);
tenpoundsBtn.addActionListener(this);
twentypoundsBtn.addActionListener(this);
C.addActionListener(this);
setVisible(true);
}
public void actionPerformed(ActionEvent e){
// event handler for the buttons
if (e.getSource() == private1Btn)
{
stalltypeTxt.setText("Private Stall Location is Chosen");
tickettypeTxt.setText("30.85");
}
else if (e.getSource() == frontBtn)
{
stalltypeTxt.setText("Front Stall Location is Chosen");
tickettypeTxt.setText("15.00");
}
else if (e.getSource() == middleBtn)
{
stalltypeTxt.setText("Middle Stall Location is Chosen");
tickettypeTxt.setText("10.20");
}
else if (e.getSource() == backBtn)
{
stalltypeTxt.setText("Back Stall Location is Chosen");
tickettypeTxt.setText("5.70");
}
else if (e.getSource() == tickettypeTxt)
{
type = Double.parseDouble(tickettypeTxt.getText());
}
else if (e.getSource() == amountticketsTxt)
{
number = Integer.parseInt(amountticketsTxt.getText());
}
else if (e.getSource() == calcBtn)
{
Workings c = new Workings();
w.setType(type);
w.setNumber(number);
double total = w.calculateBill();
totalamountTxt.setText(pounds.format(total));
}
}
}
使用名为Workings的中途完成的辅助类
public class Workings {
// private instance variables
private double type, number;
// public no-argument constructor
public Workings() { }
// public constructor with four arguments
public Workings(double t, int n)
{
type = t;
number = n;
}
// public 'set' methods
public void setType(double t) { type = t; }
public void setNumber(int n) { number = n; }
// public method to calculate the bill
public double calculateBill()
{
double total = type * number ;
return total;
}
}
答案 0 :(得分：0)
当用户在该字段中点击键盘上的Enter键时，ActionListener仅在JTextField上触发。这是不直观的，所以我想说使用ActionListener是一个很大的禁忌。
而是使用FocusListener从文本字段中获取“用户离开文本字段”事件。那应该拿起输入的数据然后它应该工作。
答案 1 :(得分：0)
这是你的问题
else if (e.getSource() == tickettypeTxt)
{
type = Double.parseDouble(tickettypeTxt.getText());
}
else if (e.getSource() == amountticketsTxt)
{
number = Integer.parseInt(amountticketsTxt.getText());
}
else if (e.getSource() == calcBtn)
{
Workings c = new Workings();
w.setType(type);
w.setNumber(number);
double total = w.calculateBill();
totalamountTxt.setText(pounds.format(total));
}
删除前两个else if并执行此操作
else if (e.getSource() == calcBtn)
{
type = Double.parseDouble(tickettypeTxt.getText());
number = Integer.parseInt(amountticketsTxt.getText());
Workings c = new Workings();
w.setType(type);
w.setNumber(number);
double total = w.calculateBill();
totalamountTxt.setText(pounds.format(total));
}