repaint() 方法只工作一次

Question

我目前正在开发一个管理 sql 数据库的 gui 项目。我目前正在添加、删除日志并显示 mysql 中存在的 table。问题是我面板上的添加和删除按钮应该 repaint/refresh 该面板上的 table 作为记录被添加或删除但是在测试时我发现重绘方法不会刷新 table 第一次使用按钮后。什么会导致这个问题？提前致谢..

public JTabbedPane addComponentToPane() {
        //Container pane = new Container();
        JTabbedPane tabbedPane = new JTabbedPane();

        JPanel card1 = new JPanel();
        JPanel card2 = new JPanel();
        JPanel card3 = new JPanel();
        JPanel card4 = new JPanel();
        JPanel card5 = new JPanel();
        JPanel card6 = new JPanel();
        JPanel card7 = new JPanel();
        JPanel card8 = new JPanel();

        card1.setLayout(new BorderLayout());
        card2.setLayout(new BorderLayout());
        card3.setLayout(new BorderLayout());
        card4.setLayout(new BorderLayout());
        card5.setLayout(new BorderLayout());
        card6.setLayout(new BorderLayout());
        card7.setLayout(new BorderLayout());
        card8.setLayout(new BorderLayout());

        JScrollPane actor = new JScrollPane(createTables("actor"));

        card1.add(actor, BorderLayout.CENTER);
        card3.add(createTables("address"), BorderLayout.CENTER);
        card4.add(createTables("category"), BorderLayout.CENTER);
        card5.add(createTables("city"), BorderLayout.CENTER);
        card6.add(createTables("country"), BorderLayout.CENTER);
        card7.add(createTables("customer"), BorderLayout.CENTER);
        card8.add(createTables("film"), BorderLayout.CENTER);

        JButton button = new JButton("Yeni Kayıt");
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                addRecord("actor");                
                card1.remove(actor);
                card1.add(createTables("actor"), BorderLayout.CENTER);
                card1.validate();
                card1.repaint();                
            }
        });
        JButton delButton = new JButton("Kayıt sil");
        delButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                delRecord("actor");
                card1.remove(actor);
                card1.add(createTables("actor"), BorderLayout.CENTER);
                card1.validate();
                card1.repaint();
            }
        });``

        card1.add(button, BorderLayout.SOUTH);
        card1.add(delButton, BorderLayout.EAST);

        tabbedPane.addTab("Şirketler", null, card1, "şirket tanımları");
        tabbedPane.addTab("Sorumlular", card2);
        tabbedPane.addTab("Varlık Grupları", card3);
        tabbedPane.addTab("Bilgi Varlıkları", card4);
        tabbedPane.addTab("Varlık Değerleri", card5);
        tabbedPane.addTab("Açıklıklar", card6);
        tabbedPane.addTab("Tehditler", card7);
        tabbedPane.addTab("Ek-A", card8);

        //pane.add(tabbedPane, BorderLayout.CENTER);
        return tabbedPane;
    }

Create tables 方法从 sql table.

创建 Jtable

private JScrollPane createTables(String tablename) {
        Connection con = null;
        Statement statement = null;
        ResultSet result = null;
        String query;
        JScrollPane jsp = null;

        try {
            Class.forName("com.mysql.jdbc.Driver").newInstance();
            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/sakila", "root", "root");
            statement = con.createStatement();
            query = "select * from " + tablename;
            result = statement.executeQuery(query);
            ResultSetMetaData rsmt = result.getMetaData();
            int columnCount = rsmt.getColumnCount();
            Vector column = new Vector(columnCount);
            for (int i = 1; i <= columnCount; i++) {
                column.add(rsmt.getColumnName(i));
            }
            Vector data = new Vector();
            Vector row = new Vector();
            while (result.next()) {
                row = new Vector(columnCount);
                for (int i = 1; i <= columnCount; i++) {
                    row.add(result.getString(i));
                }
                data.add(row);
            }
            defTableModel = new DefaultTableModel(data, column);
            table = new JTable(defTableModel) {
                @Override
                public boolean isCellEditable(int row, int column) {
                    return false;
                }
            ;
            };
            //table.setAutoCreateRowSorter(true);
            TableRowFilterSupport.forTable(table).searchable(true).apply();
            table.setRowSelectionAllowed(true);

            jsp = new JScrollPane(table);

        }
        catch (Exception e) {
            e.printStackTrace();
            // JOptionPane.showMessageDialog(null, "ERROR");
        }
        finally {
            try {
                statement.close();
                result.close();
                con.close();
            }
            catch (Exception e) {
                //JOptionPane.showMessageDialog(null, "ERROR CLOSE");
            }
        }

        return jsp;
    }

Answer 1

我发现代码中存在一些不一致之处：

actor 变量未设置为动作侦听器中添加的组件。
第一次添加 new JScrollPane(createTables("actor")) 之后您只添加 createTables("actor").

(1) 可能是导致问题的原因。

Answer 2

我认为问题出在对演员的引用上：

card1.remove(actor);
card1.add(createTables("actor"), BorderLayout.CENTER);

这里card1中没有更多引用变量actor。为了不丢失这个引用，你应该在两个 actionPerformed 方法中做这样的事情：

card1.remove(actor);
actor = new JScrollPane(createTables("actor"));
card1.add(actor, BorderLayout.CENTER);

repaint() 方法只工作一次

repaint() method doesn't work more than once

java

swing

repaint