如何在Table的单元格中嵌入下拉框?

Question

如何在Table的单元格中嵌入下拉框?
比如有三午四列的表格,想在第二行,第三列嵌入一个下拉框,鼠标点击时可以选择.
时间研究,只好来这里速求代码了.

Answer 1

/* 
 * ColorRenderer.java (compiles with releases 1.2, 1.3, and 1.4) is used by 
 * TableDialogEditDemo.java.
 */import javax.swing.BorderFactory;
import javax.swing.JLabel;
import javax.swing.JTable;
import javax.swing.border.Border;
import javax.swing.table.TableCellRenderer;
import java.awt.Color;
import java.awt.Component;public class ColorRenderer extends JLabel
                           implements TableCellRenderer {
    Border unselectedBorder = null;
    Border selectedBorder = null;
    boolean isBordered = true;    public ColorRenderer(boolean isBordered) {
        this.isBordered = isBordered;
        setOpaque(true); //MUST do this for background to show up.
    }    public Component getTableCellRendererComponent(
                            JTable table, Object color,
                            boolean isSelected, boolean hasFocus,
                            int row, int column) {
        Color newColor = (Color)color;
        setBackground(newColor);
        if (isBordered) {
            if (isSelected) {
                if (selectedBorder == null) {
                    selectedBorder = BorderFactory.createMatteBorder(2,5,2,5,
                                              table.getSelectionBackground());
                }
                setBorder(selectedBorder);
            } else {
                if (unselectedBorder == null) {
                    unselectedBorder = BorderFactory.createMatteBorder(2,5,2,5,
                                              table.getBackground());
                }
                setBorder(unselectedBorder);
            }
        }
        
        setToolTipText("RGB value: " + newColor.getRed() + ", "
                                     + newColor.getGreen() + ", "
                                     + newColor.getBlue());
        return this;
    }
}//这个是一个绘制的类

Answer 2

/* 
 * ColorEditor.java (compiles with releases 1.3 and 1.4) is used by 
 * TableDialogEditDemo.java.
 */import javax.swing.AbstractCellEditor;
import javax.swing.table.TableCellEditor;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JDialog;
import javax.swing.JTable;
import java.awt.Color;
import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;public class ColorEditor extends AbstractCellEditor
                         implements TableCellEditor,
            ActionListener {
    Color currentColor;
    JButton button;
    JColorChooser colorChooser;
    JDialog dialog;
    protected static final String EDIT = "edit";    public ColorEditor() {
        //Set up the editor (from the table's point of view),
        //which is a button.
        //This button brings up the color chooser dialog,
        //which is the editor from the user's point of view.
        button = new JButton();
        button.setActionCommand(EDIT);
        button.addActionListener(this);
        button.setBorderPainted(false);        //Set up the dialog that the button brings up.
        colorChooser = new JColorChooser();
        dialog = JColorChooser.createDialog(button,
                                        "Pick a Color",
                                        true,  //modal
                                        colorChooser,
                                        this,  //OK button handler
                                        null); //no CANCEL button handler
    }    /**
     * Handles events from the editor button and from
     * the dialog's OK button.
     */
    public void actionPerformed(ActionEvent e) {
        if (EDIT.equals(e.getActionCommand())) {
            //The user has clicked the cell, so
            //bring up the dialog.
            button.setBackground(currentColor);
            colorChooser.setColor(currentColor);
            dialog.setVisible(true);            //Make the renderer reappear.
            fireEditingStopped();        } else { //User pressed dialog's "OK" button.
            currentColor = colorChooser.getColor();
        }
    }    //Implement the one CellEditor method that AbstractCellEditor doesn't.
    public Object getCellEditorValue() {
        return currentColor;
    }    //Implement the one method defined by TableCellEditor.
    public Component getTableCellEditorComponent(JTable table,
                                                 Object value,
                                                 boolean isSelected,
                                                 int row,
                                                 int column) {
        currentColor = (Color)value;
        return button;
    }
}//这是一个实现了编辑JTable的类

Answer 3

/*
 * TableDialogEditDemo.java is a 1.4 application that requires these files:
 *   ColorRenderer.java
 *   ColorEditor.java
 */import javax.swing.JComponent;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;/**
 * This is like TableDemo, except that it substitutes a
 * Favorite Color column for the Last Name column and specifies
 * a custom cell renderer and editor for the color data.
 */
public class TableDialogEditDemo extends JPanel {
    private boolean DEBUG = false;    public TableDialogEditDemo() {
        super(new GridLayout(1,0));        JTable table = new JTable(new MyTableModel());
        table.setPreferredScrollableViewportSize(new Dimension(500, 70));        //Create the scroll pane and add the table to it.
        JScrollPane scrollPane = new JScrollPane(table);        //Set up renderer and editor for the Favorite Color column.
        table.setDefaultRenderer(Color.class,
                                 new ColorRenderer(true));
        table.setDefaultEditor(Color.class,
                               new ColorEditor());        //Add the scroll pane to this panel.
        add(scrollPane);
    }    class MyTableModel extends AbstractTableModel {
        private String[] columnNames = {"First Name",
                                        "Favorite Color",
                                        "Sport",
                                        "# of Years",
                                        "Vegetarian"};
        private Object[][] data = {
            {"Mary", new Color(153, 0, 153),
             "Snowboarding", new Integer(5), new Boolean(false)},
            {"Alison", new Color(51, 51, 153),
             "Rowing", new Integer(3), new Boolean(true)},
            {"Kathy", new Color(51, 102, 51),
             "Knitting", new Integer(2), new Boolean(false)},
            {"Sharon", Color.red,
             "Speed reading", new Integer(20), new Boolean(true)},
            {"Philip", Color.pink,
             "Pool", new Integer(10), new Boolean(false)}
        };        public int getColumnCount() {
            return columnNames.length;
        }        public int getRowCount() {
            return data.length;
        }        public String getColumnName(int col) {
            return columnNames[col];
        }        public Object getValueAt(int row, int col) {
            return data[row][col];
        }        /*
         * JTable uses this method to determine the default renderer/
         * editor for each cell.  If we didn't implement this method,
         * then the last column would contain text ("true"/"false"),
         * rather than a check box.
         */
        public Class getColumnClass(int c) {
            return getValueAt(0, c).getClass();
        }        public boolean isCellEditable(int row, int col) {
            //Note that the data/cell address is constant,
            //no matter where the cell appears onscreen.
            if (col < 1) {
                return false;
            } else {
                return true;
            }
        }        public void setValueAt(Object value, int row, int col) {
            if (DEBUG) {
                System.out.println("Setting value at " + row + "," + col
                                   + " to " + value
                                   + " (an instance of "
                                   + value.getClass() + ")");
            }            data[row][col] = value;
            fireTableCellUpdated(row, col);            if (DEBUG) {
                System.out.println("New value of data:");
                printDebugData();
            }
        }        private void printDebugData() {
            int numRows = getRowCount();
            int numCols = getColumnCount();            for (int i=0; i < numRows; i++) {
                System.out.print("    row " + i + ":");
                for (int j=0; j < numCols; j++) {
                    System.out.print("  " + data[i][j]);
                }
                System.out.println();
            }
            System.out.println("--------------------------");
        }
    }    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Make sure we have nice window decorations.
        JFrame.setDefaultLookAndFeelDecorated(true);        //Create and set up the window.
        JFrame frame = new JFrame("TableDialogEditDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        //Create and set up the content pane.
        JComponent newContentPane = new TableDialogEditDemo();
        newContentPane.setOpaque(true); //content panes must be opaque
        frame.setContentPane(newContentPane);        //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();
            }
        });
    }
}//这个是主类，用上面两个类来绘制和编辑，这是从sun 公司的例子:http://java.sun.com/docs/books/tutorial/uiswing/components/example-1dot4/index.html