java - 如何获取 JCheckBox 的状态，哪些组件位于 VerticalBox 中？

Question

我正在创建一个脚本，您可以在其中选择一个文件夹，您可以通过 JCheckBox 选择其中的组件并将它们复制到另一个文件夹。我的问题是，我使用 VerticalBox 来存储文件名并将 JCheckBox 添加到其中，所以我不知道如何获取单个 CheckBox 的状态，因为它的变量被每个新文件覆盖，我只能从最后列出的文件中读取它。

这是(未完成的)代码:

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;

import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;

public class CopyGUI extends JFrame implements ActionListener {

    private static final long serialVersionUID = 1L;
    private Box box;
    private File fromFile;
    private File toFile;
    private File folder;
    private File[] listOfFiles;
    private JButton beginButton;
    private JButton fromButton;
    private JButton toButton;
    private JCheckBox checkBox;
    private JLabel fromLabel;
    private JLabel toLabel;
    private JPanel panel;
    private JScrollPane scrollPane;
    private JTextField fromField;
    private JTextField toField;

    public CopyGUI() {
        init();
    }

    private void init() {
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setBounds(200, 200, 420, 700);
        setResizable(false);
        setTitle("File Copy");

        panel = new JPanel(null);
        add(panel);

        fromLabel = new JLabel("From:");
        fromLabel.setBounds(40, 20, 50, 20);

        fromField = new JTextField();
        fromField.setBounds(100, 20, 200, 20);

        fromButton = new JButton("Browse");
        fromButton.setBounds(300, 20, 80, 20);
        fromButton.addActionListener(this);

        toLabel = new JLabel("To: ");
        toLabel.setBounds(40, 40, 50, 20);

        toField = new JTextField();
        toField.setBounds(100, 40, 200, 20);

        toButton = new JButton("Browse");
        toButton.setBounds(300, 40, 80, 20);
        toButton.addActionListener(this);

        panel.add(fromLabel);
        panel.add(fromField);
        panel.add(fromButton);

        panel.add(toLabel);
        panel.add(toField);
        panel.add(toButton);

        beginButton = new JButton("Begin Copy");
        beginButton.setBounds(280, 620, 100, 20);
        beginButton.addActionListener(this);

        panel.add(beginButton);

        scrollPane = new JScrollPane();
        scrollPane.setBounds(40,80,340,520);

        box = Box.createVerticalBox();

        scrollPane = new JScrollPane(box);
        scrollPane.setBounds(40,80,340,520);

        panel.add(scrollPane);
    }

    public void actionPerformed(ActionEvent e) {

        if (e.getSource() == fromButton) {
            JFileChooser fileChooser = new JFileChooser();
            fileChooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);

            int op = fileChooser.showOpenDialog(this);
            if (op == JFileChooser.APPROVE_OPTION) {
                fromFile = fileChooser.getSelectedFile();
                fromField.setText(fromFile.getAbsolutePath() + "\\");
                folder = new File(fromFile.getAbsolutePath());
                listOfFiles = folder.listFiles();
            }

            box.removeAll();

            for (int i = 0; i < listOfFiles.length; i++) {
                if (listOfFiles[i].isFile()) {
                    checkBox = new JCheckBox(listOfFiles[i].getName());
                    box.add(checkBox);
                }
                else if (listOfFiles[i].isDirectory()) {
                }
            }

            panel.revalidate();
            panel.repaint();
        }

        if (e.getSource() == toButton) {
            JFileChooser fileChooser = new JFileChooser();
            fileChooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);

            int op = fileChooser.showOpenDialog(this);
            if (op == JFileChooser.APPROVE_OPTION) {
                toFile = fileChooser.getSelectedFile();
                toField.setText(toFile.getAbsolutePath() + "\\");
            }
        }

        if (e.getSource() == beginButton) {

            System.out.println(checkBox.isSelected());

        }
    }

    public static void main(String[] args) {
        new CopyGUI().setVisible(true);
    }
}

Answer 1

您需要保留对您添加的每个 JCeckBox 的引用:

    JCheckBox checkBox = new JCheckBox(listOfFiles[i].getName());
    box.add(checkBox);

    //you could keep reference in a List such as 
    List<JCheckBox> listOfChkBox = new ArrayList<>(); //class variable 
    listOfChkBox.add(checkBox);

    //or a map 
    Map<String,JCheckBox> mapOfChkBox = new HashMap<>(); //class variable
    mapOfChkBox.add(listOfFiles[i].getName(), checkBox);