java - 如何使用 JButton 从 JTextField 获取 int

Question

我试图通过单击 JButton 从 JTextField 获取 int，但我不知道如何执行此操作。我正在尝试获取 int 并将其设置为一个变量，以便我可以在我的程序中进一步使用它。

这是代码(这是整个方法):

    JFrame presets = new JFrame("Presets");
    presets.setVisible(true);
    presets.setSize(500, 500);

    JPanel gui = new JPanel(new BorderLayout(2,2));

    JPanel labelFields = new JPanel(new BorderLayout(2,2));
    labelFields.setBorder(new TitledBorder("Presets"));

    JPanel labels = new JPanel(new GridLayout(0,1,1,1));

    JPanel fields = new JPanel(new GridLayout(0,1,1,1));

    labels.add(new JLabel("Place values on Cat.2/Cat.3 at"));
    JTextField f1 = new JTextField(10);
    String text = f1.getText();
    int first = Integer.parseInt(text);
    labels.add(new JLabel("and place follow up value at"));
    fields.add(new JTextField(10));


    labelFields.add(labels, BorderLayout.CENTER);
    labelFields.add(fields, BorderLayout.EAST);

    JPanel guiCenter = new JPanel(new BorderLayout(2,2));

    JPanel submit = new JPanel(new FlowLayout(FlowLayout.CENTER));

    submit.add( new JButton("Submit") );
    guiCenter.add( submit, BorderLayout.NORTH );

    gui.add(labelFields, BorderLayout.NORTH);
    gui.add(guiCenter, BorderLayout.CENTER);

    JOptionPane.showMessageDialog(null, gui);

Answer 1

试试这个，

      String getText()

      Returns the text contained in this TextComponent.

因此，将字符串转换为整数:

try {
    int integerValue = Integer.parseInt(jTextField.getText());
}
catch(NumberFormatException ex)
{
    System.out.println("Exception : "+ex);
}