我有一個帶有 swing gui 的程序來訂購某些產品。處理訂單的類有一個，JFrame有JPanel一個JButton。按下該按鈕時，我需要處理訂單的類中的輸入。但是無法弄清楚如何一直獲得該輸入。包含按鈕的面板：public class PayPanel extends JPanel {    private double paidAmount;    private JButton payButton;    public PayPanel() {        setBorder(BorderFactory.createTitledBorder("Make Payment"));        JLabel payLabel = new JLabel("Pay with: ");        JTextField payField = new JTextField(12);        this.payButton = new JButton("Pay");        this.payButton.setPreferredSize(new Dimension(100, 20));        this.payButton.addActionListener(new ActionListener() {            public double paidAmount;            public void actionPerformed(ActionEvent e) {                this.paidAmount = Double.parseDouble(payField.getText());            }            public double getPaidAmount() {                return this.paidAmount;            }        });        setLayout(new GridBagLayout());        GridBagConstraints gridBagConstraints = new GridBagConstraints();        gridBagConstraints.gridx = 0;        gridBagConstraints.gridy = 1;        add(payLabel, gridBagConstraints);        gridBagConstraints.gridx = 1;        gridBagConstraints.gridy = 1;        add(payField, gridBagConstraints);        gridBagConstraints.weighty = 10;        gridBagConstraints.gridx = 2;        gridBagConstraints.gridy = 1;        add(payButton, gridBagConstraints);    }    public double getPaidAmount() {        ActionListener[] payButtonListeners = this.payButton.getActionListeners();        ActionListener payButtonActionListener = payButtonListeners[0];        return payButtonActionListener.getPaidAmount(); // this function is not recognized even though i defined it in the action listener like shown above in the contructor.     }我paidAmount在ActionListener聲明中添加了變量，這樣我就可以ActionListener從付款按鈕中獲取，然后調用該getPaidAmount()函數。但是當我ActionListener從中獲取payButton.getActionListeners()然后調用我聲明的函數時，java 無法識別該getPaidAmount()函數。我的問題是，我如何獲取它paidAmount并將其從按鈕傳輸到面板，然后從面板傳輸到框架，再從框架傳輸到擁有框架的類？