java - 通过选中所有必需的复选框来启用按钮

Question

我正在尝试创建一个程序，其中 JButton仅当所有 JCheckBoxes 时才会启用已检查，但我在启用特定 JButton 时遇到问题因为一旦我检查了所有 JCheckBoxes唯一JButton正在启用的是最后创建的

这是我的代码:

public class Practice extends JFrame implements ActionListener
{
    JPanel main=new JPanel();
    JPanel gui=new JPanel();
    JButton btnadd=new JButton("Add Timer");
    JPanel order=new JPanel();
    JPanel chkPanel=new JPanel();
    JButton remove=new JButton("Remove");

    public Practice()
    {

        main.setLayout(new BorderLayout());
        gui.setLayout(new FlowLayout());
        main.add(btnadd, BorderLayout.NORTH);
        main.add(gui,BorderLayout.CENTER);
        add(main);
        btnadd.addActionListener(new ActionListener() 
        {
            int ctr=0;
            @Override
            public void actionPerformed(ActionEvent e) 
            {
                ctr+=1;
                //addPanel();
                //System.out.print(x);
                addPanel(ctr);
                revalidate();
                repaint();
            }
        });

        main.add(gui);
    }


    public void addPanel(int ctr)
    {
        Border blackline=BorderFactory.createLineBorder(Color.BLACK);
        order=new JPanel();
        order.setPreferredSize(new Dimension(200,300));
        order.setLayout(new BorderLayout());
        TitledBorder title=BorderFactory.createTitledBorder(blackline);
        title.setTitleJustification(TitledBorder.LEFT);
        order.setBorder(title);
        addCheckPanel(ctr);
        addBtn();
        gui.add(order);
    }

    public void addCheckPanel(int ctr)
    {
        chkPanel=new JPanel();
        chkPanel.setLayout(new BoxLayout(chkPanel, BoxLayout.Y_AXIS));
        for(int i=0;i<ctr;i++)
            addCheck(ctr);
        order.add(chkPanel);
    }
    int y;
    public void addCheck(int ctr)
    {
        JCheckBox check=new JCheckBox("Check Me");
        chkPanel.add(check);
        y=ctr;
        check.addActionListener(listener);

    public void addBtn()
    {
        remove=new JButton("Remove");
        order.add(remove, BorderLayout.SOUTH);
        remove.setEnabled(false);
        remove.addActionListener(listener);
    }

    public static void main(String args[])
    {
        TimerPractice p=new TimerPractice();
        p.setSize(1000,800);
        p.setVisible(true);
        p.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        p.setLocationRelativeTo(null);
    }

    ActionListener listener=new ActionListener()
    {
        @Override
        public void actionPerformed(ActionEvent e)
        {
             Object source = e.getSource();
             if (source instanceof Component) 
             {
                Component comp = (Component)source;
                gui.remove(comp.getParent());
                revalidate();
                repaint();
             }
         }
    };


    @Override
    public void actionPerformed(ActionEvent e) 
    {

    }
}

Answer 1

您需要隔离和分隔您的工作单元。例如，您的 order 面板具有控件和功能，最好将其分为自己的类，在类中它可以独立于自身的其他实例来维护自己的状态，例如...

您可以提取主类的大部分代码并创建一个单独的类，例如 OrderPane...

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JPanel;
import javax.swing.border.Border;
import javax.swing.border.TitledBorder;

public class OrderPane extends JPanel {

    private JPanel chkPanel;
    private int selectedCount = 0;
    private int checkCount = 0;

    private JButton removeButton;

    public OrderPane(int checkCount) {
        setLayout(new BorderLayout());

        Border blackline = BorderFactory.createLineBorder(Color.BLACK);
        TitledBorder title = BorderFactory.createTitledBorder(blackline);
        title.setTitleJustification(TitledBorder.LEFT);
        setBorder(title);

        this.checkCount = checkCount;

        addCheckPanel();
        addBtn();

    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(200, 300);
    }

    public void addCheckPanel() {
        chkPanel = new JPanel();
        chkPanel.setLayout(new BoxLayout(chkPanel, BoxLayout.Y_AXIS));
        for (int i = 0; i < checkCount; i++) {
            addCheck();
        }
        add(chkPanel);
    }

    public void addCheck() {
        JCheckBox check = new JCheckBox("Check Me");
        chkPanel.add(check);
        check.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                JCheckBox cb = (JCheckBox) e.getSource();
                if (cb.isSelected()) {
                    selectedCount++;
                } else {
                    selectedCount--;
                }
                if (selectedCount == checkCount) {
                    removeButton.setEnabled(true);
                }
            }
        });
    }

    public void addBtn() {
        removeButton = new JButton("Remove");
        add(removeButton, BorderLayout.SOUTH);
        removeButton.setEnabled(false);
        removeButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                Object source = e.getSource();
                if (source instanceof Component) {
                    Component comp = (Component) source;
                    Component myParent = comp.getParent();
                    Container yourParent = myParent.getParent();
                    yourParent.remove(myParent);
                    yourParent.revalidate();
                    yourParent.repaint();
                }
            }
        });
    }

}

您可以在需要时创建此类的新实例，并根据需要将其添加到您的 UI，例如...

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Practice extends JFrame {

    JPanel main = new JPanel();
    JPanel gui = new JPanel();
    JButton btnadd = new JButton("Add Timer");

    public Practice() {

        main.setLayout(new BorderLayout());
        gui.setLayout(new FlowLayout());
        main.add(btnadd, BorderLayout.NORTH);
        main.add(gui, BorderLayout.CENTER);
        add(main);

        final Random rnd = new Random();
        btnadd.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                OrderPane orderPane = new OrderPane(rnd.nextInt(10));
                gui.add(orderPane);
                gui.revalidate();
                gui.repaint();
            }
        });

        main.add(gui);
    }

    public static void main(String args[]) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                Practice p = new Practice();
                p.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                p.setSize(800, 600);
                p.setLocationRelativeTo(null);
                p.setVisible(true);
            }
        });
    }
}

您可能会从 Object-Oriented Programming Concepts 找到一些信息和 Inheritance有用且无意冒犯，在处理像 UI 这样复杂的事情之前我会先了解这些主题;)

附注

通常，我会将某种“ Controller ”接口(interface)传递给OrderPane，它将提供从主 UI 中删除组件的功能以及其他功能OrderPane 可能需要提供反馈。

其中一些反馈可以通过观察者/监听器模式提供，例如当计时器超时时，最好向注册的监听器提供某种事件，然后可能调用“ Controller ”上的方法 - 恕我直言

...但是让我们一次处理一个概念...