java - 构造函数中的 Action 监听器

我正在尝试创建带有框架的NewCard类。如何在NewCard类的构造函数中的元素上添加Actionlisteners？我不能将Actionlistener放入构造函数中，而当将其放在外面时，对于saveButtonListener块，元素“字段”不可见。

第二个问题：class Record在try块中抛出两个异常，为什么try块会产生错误？

package Interface;

import javax.swing.*;
import java.awt.*;
import java.util.*;
import java.awt.event.*;
import Engine.*;

class NewCard extends JFrame
{
    NewCard()
    {
        JFrame Card = new JFrame();
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        setTitle("New Card");
        setSize(340, 580);
        setVisible(true);
        Container contentPane = getContentPane();
        contentPane.setLayout(null);

        // Field

        JTextField field = new JTextField();
        contentPane.add(field);
        field.setBounds(110,15,200,25);

        // Button:

        JButton saveButton = new JButton("Save");
        powZawartosci.add(saveButton);
        saveButton.setBounds(95,495,150,25);

        saveButtonListener listener1 = new saveButtonListener();
        saveButton.addActionListener(listener1);
    }

    private class saveButtonListener implements ActionListener
    {
        try
        {
            @Override
            public void actionPerformed(ActionEvent event)
            {
                new Record(field.getText());
            }
        }
        catch(IOException e)
        {
            System.out.println("IOException");
        }
        catch(SQLException e)
        {
            System.out.println("SQLException");
        }
        finally
        {

        }
    }
}

最佳答案

您可以将动作侦听器放入构造函数中，如下所示：

final JTextField field = new JTextField();
...
saveButton.addActionListener(new ActionListener() {
   @Override
   public void actionPerformed(ActionEvent event) {
      new Record(field.getText());
   }

});