Question

我的问题是当我选择我的组合框时，JTable不会更新。当我选择data = null;时，我在下面提供的程序应删除所有数据（LA）。该表不会更新。

 public class minimumExample extends JFrame {

    private JTabbedPane tabbedPane;
    private FilteredTabPanel filteredTabPanel;

    public void createTabBar() {

        tabbedPane = new JTabbedPane(JTabbedPane.TOP);

        filteredTabPanel = new FilteredTabPanel();
        tabbedPane.addTab("Test", filteredTabPanel.createLayout());

        add(tabbedPane);
        tabbedPane.setTabLayoutPolicy(JTabbedPane.SCROLL_TAB_LAYOUT);
    }

    private void makeLayout() {

        setTitle("Test App");
        setLayout(new BorderLayout());
        setPreferredSize(new Dimension(1000, 500));
        createTabBar();
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setVisible(true);

    }

    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 FilteredTabPanel extends JPanel {

        private JPanel selectionArea;
        private JLabel lCity;
        private JComboBox cityBox;
        private JTable filterTable;
        String[] columnNames = {"Cities"};
        String[][] data = {
                {"NY"}, {"NY"}, {"NY"}, {"NY"}, {"LA"}, {"LA"},{"Columbia"},{"DC"},{"DC"},{"DC"},{"DC"},{"DC"},{"DC"}
            };

        private JScrollPane scrollPane;

        public JPanel createLayout() {
            JPanel panel = new JPanel(new GridLayout(0, 1));
            //add panels to the layout
            panel.add(addButtons());    
            panel.add(showTable());

            repaint();
            revalidate();

            return panel;
        }

        public JPanel addButtons(){

            selectionArea = new JPanel(new FlowLayout(FlowLayout.LEFT));

            lCity = new JLabel("City");

            String[] fillings = {"NY", "LA", "Columbia", "DC"};
            cityBox = new JComboBox(fillings);

            cityBox.addActionListener(new ActionListener() {

                private String cityFilter;

                @Override
                public void actionPerformed(ActionEvent arg0) {
                    //2. get data
                    cityFilter = cityBox.getSelectedItem().toString();

                    if(cityFilter.equals("LA")) {
                        data = null;
                    }

                    showTable();
                    repaint();
                }
            });

            selectionArea.add(lCity);
            selectionArea.add(cityBox);

            selectionArea.repaint();

            return selectionArea;
        }

        private JScrollPane showTable() {

            filterTable =new JTable(data, columnNames);
            filterTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);

            scrollPane = new JScrollPane(filterTable);

            scrollPane.repaint();
            scrollPane.validate();

            return scrollPane;
        }
    }
}

如您所见，表格未更新。我有什么建议吗？

Answer 1

不是通过调用showTable来创建对象的新实例（它永远不会以任何方式添加到屏幕上），这只会完全弄乱对象引用，请尝试重置{{1} }，例如......

TableModel

仔细查看How to Use Tables了解更多详情

选择组合框时，表不会更新

1 个答案: