Java * 未定义 JTextField 的运算符，双精度 [重复]

Question

我在项目的侦听器中收到错误“* Operator Undefined for JTextField, Double”。这是一个 Java GUI 项目，我们需要有两个文本字段，一个用于“小时”，另一个用于“费率”。我们还需要有一个列出员工类型的组合框和一个计算按钮。我在监听器下的 switch case 2 (pay = hours * payRate;) 中遇到错误。如何转换文本以便我可以将小时数乘以 payRate？

public class EmployeeControls extends JPanel
{
private JLabel cost, inputLabel1, inputLabel2, outputLabel, resultLabel;
private JTextField hours, rate;
private JComboBox employeeCombo;
private JButton calculateButton;
private double pay, bonus, payRate;

public EmployeeControls()
{   
    inputLabel1 = new JLabel("Hours:");
    inputLabel2 = new JLabel("Rate:");
    outputLabel = new JLabel("Pay:");
    resultLabel = new JLabel("------");
    hours = new JTextField(2);
    rate = new JTextField(5);
    hours.addActionListener(new CalcListener());
    rate.addActionListener(new CalcListener());

    String[] employeeTypes = {"Select an Employee 
    Type","Salaried","Hourly","Volunteer"};


    employeeCombo = new JComboBox(employeeTypes);

    calculateButton = new JButton("Calculate Pay");

    cost = new JLabel("Pay: " + pay);

    setPreferredSize(new Dimension (400, 100));
    setBackground(Color.cyan);

    add(employeeCombo);
    add(calculateButton);

    calculateButton.addActionListener(new CalcListener());

   }

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

        String text = rate.getText();
        String strRate = Double.toString(payRate);

        String text2 = hours.getText();
        String strHours = Double.toString(hours);


        int employeeType = employeeCombo.getSelectedIndex();

        switch(employeeType)
        {
            case 0:
                JOptionPane.showMessageDialog(null, "Select an Employee 
       Type");
                break;
            case 1:
                pay = (2000.00 + bonus);
                JOptionPane.showMessageDialog(null, "Enter bonus amount");
                break;
            case 2:
                pay = hours * payRate;
                break;
            case 3:
                pay = 0.00;
                break;

        }
        cost.setText("Cost = " + pay);
     }

     }
     }

Answer 1

您正在尝试对 JTextField 进行乘法运算：这没有意义。

要解决此问题，请使用hours.getText() 获取文本字段的值，然后使用Integer.parseInt(hours.getText()) 将其解析为int。所以它变成了：

pay = Integer.parseInt(hours.getText()) * payRate