如何實現復選框列表java

Question

可能是一個菜鳥問題，但我是 Java 新手。 我需要一個復選框列表，我發現它在 Swing 中不受支持，但我在這里找到了這個自定義控件

http://www.devx.com/tips/Tip/5342

所以我創建了一個名為CheckBoxList的類文件，並將鏈接中的代碼復制到其中：

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

public class CheckBoxList extends JList
{
   protected static Border noFocusBorder =
                                 new EmptyBorder(1, 1, 1, 1);

   public CheckBoxList()
   {
      setCellRenderer(new CellRenderer());

      addMouseListener(new MouseAdapter()
         {
            public void mousePressed(MouseEvent e)
            {
               int index = locationToIndex(e.getPoint());

               if (index != -1) {
                  JCheckBox checkbox = (JCheckBox)
                              getModel().getElementAt(index);
                  checkbox.setSelected(
                                     !checkbox.isSelected());
                  repaint();
               }
            }
         }
      );

      setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
   }

   protected class CellRenderer implements ListCellRenderer
   {
      public Component getListCellRendererComponent(
                    JList list, Object value, int index,
                    boolean isSelected, boolean cellHasFocus)
      {
         JCheckBox checkbox = (JCheckBox) value;
         checkbox.setBackground(isSelected ?
                 getSelectionBackground() : getBackground());
         checkbox.setForeground(isSelected ?
                 getSelectionForeground() : getForeground());
         checkbox.setEnabled(isEnabled());
         checkbox.setFont(getFont());
         checkbox.setFocusPainted(false);
         checkbox.setBorderPainted(true);
         checkbox.setBorder(isSelected ?
          UIManager.getBorder(
           "List.focusCellHighlightBorder") : noFocusBorder);
         return checkbox;
      }
   }
}

問題是我不知道如何在我的 GUI 文件中實現它。 我嘗試了很多代碼，但他們從未展示過示例。 只是

要使用該類，只需將其實例化，然后通過調用 setListData 將 JCheckBox 對象（或 JCheckBox 對象的子類）數組傳遞給它

那么這是否意味着我不會在圖形設計視圖中看到該控件？ 我的客戶希望能夠自己編輯它並添加內容，所以我希望它盡可能簡單和圖形化。 如果有人可以展示實例化它的示例或給出一個很好的提示，我將不勝感激。 謝謝！

Answer 1

你能告訴我怎么做嗎？

使用一列JTable和適當的渲染器和編輯器。 基於此示例，下面的代碼依賴於Boolean.Class類型的數據值的默認呈現器。 這里引用了一個更一般的例子。

import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
import javax.swing.BorderFactory;
import javax.swing.DefaultListModel;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableCellRenderer;

/** @see https://stackoverflow.com/a/13919878/230513 */
public class CheckTable {

    private static final CheckModel model = new CheckModel(5000);
    private static final JTable table = new JTable(model) {

        @Override
        public Dimension getPreferredScrollableViewportSize() {
            return new Dimension(150, 300);
        }

        @Override
        public Component prepareRenderer(TableCellRenderer renderer, int row, int column) {
            JCheckBox jcb = (JCheckBox) super.prepareRenderer(renderer, row, column);
            jcb.setHorizontalTextPosition(JCheckBox.LEADING);
            jcb.setText(String.valueOf(row));
            return jcb;
        }
    };

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                JFrame f = new JFrame("CheckTable");
                f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                f.setLayout(new GridLayout(1, 0));
                f.add(new JScrollPane(table));
                f.add(new DisplayPanel(model));
                f.pack();
                f.setLocationRelativeTo(null);
                f.setVisible(true);
            }
        });
    }

    private static class DisplayPanel extends JPanel {

        private DefaultListModel dlm = new DefaultListModel();
        private JList list = new JList(dlm);

        public DisplayPanel(final CheckModel model) {
            super(new GridLayout());
            this.setBorder(BorderFactory.createTitledBorder("Checked"));
            this.add(new JScrollPane(list));
            model.addTableModelListener(new TableModelListener() {

                @Override
                public void tableChanged(TableModelEvent e) {
                    dlm.removeAllElements();
                    for (Integer integer : model.checked) {
                        dlm.addElement(integer);
                    }
                }
            });
        }
    }

    private static class CheckModel extends AbstractTableModel {

        private final int rows;
        private List<Boolean> rowList;
        private Set<Integer> checked = new TreeSet<Integer>();

        public CheckModel(int rows) {
            this.rows = rows;
            rowList = new ArrayList<Boolean>(rows);
            for (int i = 0; i < rows; i++) {
                rowList.add(Boolean.FALSE);
            }
        }

        @Override
        public int getRowCount() {
            return rows;
        }

        @Override
        public int getColumnCount() {
            return 1;
        }

        @Override
        public String getColumnName(int col) {
            return "Column " + col;
        }

        @Override
        public Object getValueAt(int row, int col) {
                return rowList.get(row);
        }

        @Override
        public void setValueAt(Object aValue, int row, int col) {
            boolean b = (Boolean) aValue;
            rowList.set(row, b);
            if (b) {
                checked.add(row);
            } else {
                checked.remove(row);
            }
            fireTableRowsUpdated(row, row);
        }

        @Override
        public Class<?> getColumnClass(int col) {
            return getValueAt(0, col).getClass();
        }

        @Override
        public boolean isCellEditable(int row, int col) {
            return true;
        }
    }
}

Answer 2

代碼需要一個 JCheckBox 對象列表 - 所以這是有效的

CheckBoxList cbList = new CheckBoxList();  // the class you have
JCheckBox check1 = new JCheckBox("One");
JCheckBox check2 = new JCheckBox("two");
JCheckBox[] myList = { check1, check2};    list of checkbox object
cbList.setListData(myList);   // set the list data for the object

Small Swing 程序使用您的課程如下

 util;

import javax.swing.*;

public class HelloWorldSwing {
private static void createAndShowGUI() {
    //Create and set up the window.
    JFrame frame = new JFrame("HelloWorldSwing");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    CheckBoxList cbList = new CheckBoxList();
    JCheckBox check1 = new JCheckBox("One");
    JCheckBox check2 = new JCheckBox("two");
    JCheckBox[] myList = { check1, check2};
    cbList.setListData(myList);
    frame.getContentPane().add(cbList);

    //Display the window.
    frame.pack();
    frame.setVisible(true);
}

public static void main(String[] args) {
    //Schedule a job for the event-dispatching thread:
    //creating and showing this application's GUI.
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            createAndShowGUI();
        }
    });
}

}