如何在Java GUI上循环数据？

Question

private void enterData() {
    numberOfCars = 10; // the maximum number of cars to be examined will be no more than 10
    carRegistration = registrationField.getText(); // car registration is what users type in the registration field
    carAge = Integer.parseInt((String) ageCombo.getSelectedItem()); // the age is to be selected from the combo box
    boolean accident = accidentCheckBox.isSelected(); // the accident status depends on whether or not the checkbox is ticked
    discount = Fee * 0.25; // declaring that the discount is 25% of the fee

    textArea.setText(String.format("%10s %10s %10s %10s", "Registration", "Age", "Accident", "Fee\n")); // placing the headings of the four categories of information into text
    textArea.append(String.format("--------------------------------------------\n")); // underline separates the titles of categories from the information of each car
    textArea.append(String.format("%10s %10s %10s %10s", carRegistration, carAge, Accident, "$" +Fee)); // the four categories information displayed into text for each car

    if(accidentCheckBox.isSelected()) // if the accident checkbox is displayed, the accident status should display as YES
       Accident = "YES";
    else
       Accident = "NO"; // if the accident checkbox is displayed, the accident status would display as NO

    if(numberOfCars > 10)
       JOptionPane.showMessageDialog(this, "You have reached the limit of cars to enter"); // display error message if the number of cars exceed 10

    if (carAge > 5)
      Fee = 350.00; // if the car is above 5 years of age, the fee would be $350.00

    if(carAge<=5)
      Fee = 200.00; // if the car is under or equal to 5 years of age, the fee would be $200.00

    if(accidentCheckBox.isSelected())
        Fee = Fee; // if the car has been in an accident, the fee will not change
    else
        Fee = Fee - discount; // if the car has not been in an accident, the fee will be discounted

    if(registrationField.getText().equals(""))
    {
        JOptionPane.showMessageDialog(this, "Please enter a car's registration"); // error message if car registration isn't entered
    }

    registrationField.setText(""); // reset the registration field when data is entered

    ageCombo.setSelectedIndex(0); // reset the combo box to the default number selected when data is entered

    accidentCheckBox.setSelected(false); // reset the check box to its default state when data is entered

    registrationField.requestFocus();
} // enterData

我想循环carRegistration、carAge、Accident和Fee的文本，我的任务是输入至少10辆车的详细信息，但是在GUI上只有一行是活动的文本，如果我要输入新数据，它的文本将替换我以前输入的文本，我希望它被输入到新行

Answer 1

您正在通过textArea.setText()覆盖文本。在循环之前只执行一次，或者在将文本设置为文本区域时创建一个布尔标志并将其设置为true，并在尝试再次设置之前在循环中每次检查它