如何将ActionListener添加到JCheckBox?

本文介绍了如何将ActionListener添加到JCheckBox?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

所以我的程序接收一个.csv文件并加载数据并显示它.加载数据后，它将为数据中存在的每个列标题创建一个新的 JCheckBox .如何添加 ActionListener ，以便当用户勾选/取消选中任何框时，它应该执行某些功能?

So my program takes in a .csv file and loads the data and displays it. When data is loaded in, it creates a new JCheckBox for every column header there is in the data. How do I add an ActionListener such that when the user ticks/unticks any of the boxes, it should do a certain function?

加载数据后，它将通过以下代码更新 JPanel :

When data is loaded in, it updates the JPanel by the code:

    public void updateChecklistPanel(){

        checklistPanel.removeAll();
        checklistPanel.setLayout(new GridLayout(currentData.getColumnNames().length, 1, 10, 0));
        for (String columnName : currentData.getColumnNames()){
            JCheckBox checkBox = new JCheckBox();
            checkBox.setText(columnName);
            checklistPanel.add(checkBox);
        }
        checklistPanel.revalidate();
        checklistPanel.repaint();
    }

我在底部也有以下内容:

I also have the following at the bottom:

    @Override
    public void actionPerformed(ActionEvent e) {

        if (e.getSource() == newDataFrameItem){
            newFile();
            System.out.println("New DataFrame Loaded in");
        }
        if (e.getSource() == loadDataFrameItem){
            loadFile();
            System.out.println(".csv Data loaded into DataFrame.");
        }
        if (e.getSource() == saveDataFrameItem){
            System.out.println("Saved the data to a .csv file");
        }

    }

我想做的是，当未选中复选框时，它应该在 JTable 中隐藏一列，而在选中时，它应该重新显示该列.

What I'm trying to do is that when a checkbox is unticked, it should hide a column in the JTable and when ticked, it should redisplay the column.

我想出的解决方案是使变量 allColumnHeaders 成为字符串的ArrayList.然后，我还有一个变量 shownColumnHeaders ，它是布尔值的ArrayList.当用户想要显示/隐藏列时， showColumn(String columnName)和 hideColumn(String columnName)函数在 allColumnHeaders中找到列名的索引并将 shownColumnHeaders 中索引的布尔值设置为true/false.

The solution that I have come up with is to make a variable allColumnHeaders that is an ArrayList of Strings. I then also have a variable shownColumnHeaders that is an ArrayList of Booleans. When the user wants to show/hide a column, the showColumn(String columnName) and hideColumn(String columnName) function finds the index of the column Name in allColumnHeaders and sets the Boolean value of the index in shownColumnHeaders to either true/false.

此过程将创建一个新的表模型，仅在该列的布尔值为true时才添加该列.然后，它将表的模型设置为新的表模型.

It the proceeds to create a new table model where the columns are only added if the Boolean value for that column is true. It will then set the model for the table to the new table model.

下面的代码如下所示:

import java.awt.*;
import java.util.ArrayList;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;

public class MRE extends JPanel {

    private static JTable table;
    private static ArrayList<String> allColumnHeaders = new ArrayList<>();
    private static ArrayList<Boolean> shownColumnHeaders = new ArrayList<>();

    private static void createAndShowGUI()
    {
        table = new JTable(5, 7);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        JScrollPane scrollPane = new JScrollPane( table );

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

        for (int i = 0; i < table.getColumnCount(); i++) {
            String column = table.getColumnName(i);
            allColumnHeaders.add(column);
            JCheckBox checkBox = new JCheckBox(column);

            checkBox.addActionListener(event -> {
                JCheckBox cb = (JCheckBox) event.getSource();
                if (cb.isSelected()) {
                    System.out.println(checkBox.getText() + " is now being displayed");
                    showColumn(checkBox.getText());
                } else {
                    System.out.println(checkBox.getText() + " is now being hidden");
                    hideColumn(checkBox.getText());
                }

                table.setModel(createTableModel());
            });

            checkBox.setSelected( true );
            buttons.add( checkBox );

            shownColumnHeaders.add(true);

        }

        JPanel wrapper = new JPanel();
        wrapper.add( buttons );

        JFrame frame = new JFrame("MRE");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(scrollPane, BorderLayout.CENTER);
        frame.add(wrapper, BorderLayout.LINE_END);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationByPlatform( true );
        frame.setVisible( true );
    }

    public static DefaultTableModel createTableModel(){

        DefaultTableModel tableModel = new DefaultTableModel(0, 0);
        String[] columnValues = new String[1];
        for (int i = 0; i < shownColumnHeaders.size(); i++){
            if (shownColumnHeaders.get(i)){
                tableModel.addColumn(allColumnHeaders.get(i), columnValues);
            }
        }

        return tableModel;
    }

    public static void showColumn(String columnName){
        for (int i = 0; i < allColumnHeaders.size(); i++) {
            if (allColumnHeaders.get(i).equals(columnName)){
                shownColumnHeaders.set(i, true);
            }
        }
    }

    public static void hideColumn(String columnName){
        for (int i = 0; i < allColumnHeaders.size(); i++) {
            if (allColumnHeaders.get(i).equals(columnName)){
                shownColumnHeaders.set(i, false);
            }
        }
    }

    public static void main(String[] args) throws Exception
    {
        SwingUtilities.invokeLater( () -> createAndShowGUI() );
    }

}

推荐答案

这仅演示如何创建基本的MRE:

This only demonstrates how to create a basic MRE:

csv文件不相关.
模型中的数据无关.
您的loadFile，newFile和saveFile按钮无关.
TableModel不相关

您的问题是有关基于表的列向动态创建的复选框添加ActionListener.

Your question is about adding an ActionListener to dynamically created checkboxes based on the columns of the table.

因此，您需要的是一个带有一些列和相应复选框的表.

So all you need is a table with some columns and the resulting checkboxes.

import java.awt.*;
import javax.swing.*;

public class MRE extends JPanel
{
    private static void createAndShowGUI()
    {
        JTable table = new JTable(5, 7);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        JScrollPane scrollPane = new JScrollPane( table );

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

        for (int i = 0; i < table.getColumnCount(); i++)
        {
            String column = table.getColumnName(i);
            JCheckBox checkBox = new JCheckBox("Display " + column);
            checkBox.setSelected( true );
            buttons.add( checkBox );
        }

        JPanel wrapper = new JPanel();
        wrapper.add( buttons );

        JFrame frame = new JFrame("MRE");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(scrollPane, BorderLayout.CENTER);
        frame.add(wrapper, BorderLayout.LINE_END);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationByPlatform( true );
        frame.setVisible( true );
    }

    public static void main(String[] args) throws Exception
    {
        SwingUtilities.invokeLater( () -> createAndShowGUI() );
    }
}

如果您可以修改此内容以演示如何使用可重用类"，则为了管理列的可见性，那么我将更新上面的代码，以将我的可重用类与另外4行代码一起使用.

If you can modify this to demonstrate how to use your "reusable class" to manage column visibility, then I will update the above code to use my reusable class with 4 additional lines of code.