Question

我通过ArrayList<Items>动态地向JPanel添加项目。基本上，items对象看起来像：

public class Item {

    private JComponent component;
    private String functionality;

    public Item(JComponent component, String functionality) {
        super();
        this.component = component;
        this.functionality = functionality;
    }

    public JComponent getComponent() {
        return component;
    }

    public void setComponent(JComponent component) {
        this.component = component;
    }

    public String getFunctionality() {
        return functionality;
    }

    public void setFunctionality(String functionality) {
        this.functionality = functionality;
    }
}

这里我动态添加我的按钮:(如果需要，请尝试示例）

public class minimumExample extends JFrame {

    private JButton addItem;

    private JComboBox itemBox;

    private String[] itemSelect = { "test1", "test2" };

    private JPanel addUpperPane;

    private JPanel addLowerPane;

    private ArrayList<Item> displayedItems = new ArrayList<Item>();

    private JButton upButton;

    private JButton downButton;

    private JButton deleteButton;

    public void createControlPane() {

        addUpperPane = new JPanel();
        addLowerPane = new JPanel(new GridLayout(0, 1));

        addItem = new JButton("Add item");
        upButton = new JButton("Up");
        downButton = new JButton("Down");
        deleteButton = new JButton("Delete");

        itemBox = new JComboBox(itemSelect);

        addItem.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {

                if(itemBox.getSelectedItem().toString().equals("test1")) {
                    displayedItems.add(new Item( new ButtonComp().butt(), "test1"));                
                    validate();
                    repaint();
                }

                if(itemBox.getSelectedItem().toString().equals("test2")) {
                    displayedItems.add(new Item( new LabelComp().label(), "test2"));    
                    validate();
                    repaint();
                }


                for (int i = 0; i < displayedItems.size(); i++) {
                    addLowerPane.add(displayedItems.get(i).getComponent());
                    validate();
                    repaint();
                }
            }
        });



        addUpperPane.add(itemBox, BorderLayout.EAST);
        addUpperPane.add(addItem, BorderLayout.WEST);
        addUpperPane.add(new JLabel(" | "), BorderLayout.WEST);
        addUpperPane.add(upButton, BorderLayout.WEST);
        addUpperPane.add(downButton, BorderLayout.WEST);
        addUpperPane.add(deleteButton, BorderLayout.WEST);
        addUpperPane.add(new JSeparator(JSeparator.HORIZONTAL));

        //put everything together

        add(addUpperPane, BorderLayout.NORTH);
        add(addLowerPane, BorderLayout.SOUTH);

        repaint();

    }

    private void makeLayout() {

        setTitle("Test App");
        setLayout(new BorderLayout());
        setPreferredSize(new Dimension(1000, 500));

        createControlPane();
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setVisible(true);

    }


    /**
     * starts the GUI
     */
    public void start() {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                makeLayout();   
            }
        });
    }

    public static void main(String[] args) throws IOException {
        minimumExample ex = new minimumExample();
        ex.start();
    }



    public class ButtonComp extends Component {

        public JPanel butt() {
            JPanel panel = new JPanel();

            JButton button = new JButton("Test1");
            JCheckBox check = new JCheckBox();

            panel.add(button);
            panel.add(check);

            return panel;
        }
    }

    public class LabelComp extends Component {

        public JPanel label() {
            JPanel panel = new JPanel();

            JLabel label = new JLabel("Test2");
            JCheckBox check = new JCheckBox();

            panel.add(label);
            panel.add(check);

            return panel;
        }
    }
}

程序基本上是这样的：

enter image description here

我的问题是按钮Up, Down and Delete不起作用，因为我不知道如何从窗格中获取所选元素以从所有组件所在的列表中删除它。有关如何制作的任何建议这项工作？

我非常感谢你的回答！

更新

我将我的代码更改为您的规格@cghislai但它不起作用。自己尝试一下：

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSeparator;

public class minimumExample extends JFrame {

    private JButton addItem;

    private JComboBox itemBox;

    private String[] itemSelect = { "test1", "test2" };

    private JPanel addUpperPane;

    private JPanel addLowerPane;

    private List<CheckableItem> displayedItems = new ArrayList<CheckableItem>();

    private JButton upButton;

    private JButton downButton;

    private JButton deleteButton;

    public void createControlPane() {

        addUpperPane = new JPanel();
        addLowerPane = new JPanel(new GridLayout(0, 1));

        addItem = new JButton("Add item");
        upButton = new JButton("Up");
        downButton = new JButton("Down");
        deleteButton = new JButton("Delete");

        itemBox = new JComboBox(itemSelect);

        addItem.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {

                if(itemBox.getSelectedItem().toString().equals("test1")) {
                    ButtonComp butt = new ButtonComp();
                    butt.init();
                    displayedItems.add(butt);
                    validate();
                    repaint();
                }

                if(itemBox.getSelectedItem().toString().equals("test2")) {
                    //                  displayedItems.add(new CopyOfItem( new LabelComp(), "test2"));  
                    validate();
                    repaint();
                }


                for (int i = 0; i < displayedItems.size(); i++) {
                    addLowerPane.add(displayedItems.get(i).getComponent());
                    validate();
                    repaint();
                }
            }
        });


        deleteButton.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {

                Iterator<CheckableItem> it = displayedItems.iterator();
                while (it.hasNext()) {
                    CheckableItem next = it.next();
                    if (next.isSelected()) {
                        addLowerPane.remove(next.getComponent());
                        it.remove();
                        continue;
                    }
                }

            }
        });

        addUpperPane.add(itemBox, BorderLayout.EAST);
        addUpperPane.add(addItem, BorderLayout.WEST);
        addUpperPane.add(new JLabel(" | "), BorderLayout.WEST);
        addUpperPane.add(upButton, BorderLayout.WEST);
        addUpperPane.add(downButton, BorderLayout.WEST);
        addUpperPane.add(deleteButton, BorderLayout.WEST);
        addUpperPane.add(new JSeparator(JSeparator.HORIZONTAL));

        //put everything together

        add(addUpperPane, BorderLayout.NORTH);
        add(addLowerPane, BorderLayout.SOUTH);

        repaint();

    }

    private void makeLayout() {

        setTitle("Test App");
        setLayout(new BorderLayout());
        setPreferredSize(new Dimension(1000, 500));

        createControlPane();
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setVisible(true);

    }


    /**
     * starts the GUI
     */
    public void start() {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                makeLayout();   
            }
        });
    }

    public static void main(String[] args) throws IOException {
        minimumExample ex = new minimumExample();
        ex.start();
    }




    public abstract class CheckableItem {

        protected JCheckBox check;

        public boolean isSelected() {
            return check.isSelected();
        }

        public abstract Component getComponent();

    }

    public class ButtonComp extends CheckableItem {
        JPanel panel = new JPanel();

        public void init() {
            JButton button = new JButton("Test1");
            check = new JCheckBox();
            panel.add(button);
            panel.add(check);
        }

        @Override
        public Component getComponent() {
            return panel;
        }

    }

    public class LabelComp extends JPanel {

        public void label() {
            //          JPanel panel = new JPanel();

            JLabel label = new JLabel("Test2");
            JCheckBox check = new JCheckBox();

            add(label);
            add(check);

        }
    }
}

Answer 1

为什么不从JPanel扩展 ButtomComp 和 LabelComp ？这会解决我想到的很多问题。例如：

public class ButtonComp extends JPanel {

    JButton button;
    JCheckBox check = new JCheckBox();


    public ButtonComp() {

        button = new JButton("Test1");

        this.add(button);
        this.add(check);
    }
}

然后您需要做的就是遍历您的项目并查看组件中的复选框：

for (int i = 0; i < displayedItems.size(); i++) {

    if (displayedItems.get(i).check.isSelected()) {
        displayedItems.remove(i);
    }
}

注意：尚未测试此代码。但你应该明白这一点。

Answer 2

您需要遍历所有商品，检查是否选中了商品复选框，如果是这种情况，请从面板中移除商品。我将使用JCheckbox和Component的getter创建一个抽象的CheckableItem类。然后，对于每个项目，如果选中该复选框，则从父项中删除该组件。

public abstract class CheckableItem {
    protected JCheckbox checkbox;
    public boolean isSelected() {
        return checkbox.isSelected();
    }
    public abstract Component getComponent();
}
public class ButtonComp extends CheckableItem {
    private Panel panel;
    public void init() {
        checkbox = new JCheckbox;
        panel = new JPanel();
        panel.add(new JButton());
        panel.add(checkbox);
    }
    public Component getComponent() {
        return panel;
    }
}

然后跟踪您的物品：

 private List<CheckableItem> items = new ArrayList<>();
    // ...
    ButtonComp comp = new ButtonComp();
    comp.init();  
    items.add(comp);

然后删除所有选中的内容：

Iterator<CheckbleItem> it = items.iterator();
while (it.hasNext()) {
    CheckableItem next = it.next();
    if (next.isSelected()) {
        mainPanel.remove(next.getComponent());
        it.remove();
        continue;
    }
}

从JPanel获取所选组件

2 个答案: