JTable和JButton

Question

我正在编写java桌面应用程序.我有一些textareas来从用户那里获取数据.A JButton,它接受输入和处理.并且a JTable填充处理的数据.

这是我从main调用的构造函数.

    public ChangeButtonLabel()
    {
        JFrame f=new JFrame();
            f.setLayout(null);

        JLabel lab1=new JLabel("Name");
            JLabel lab2=new JLabel("Age");

        //table=new JTable(model);

        text1=new JTextField(20);
            text2=new JTextField(20);


        button=new JButton("OK");

            lab1.setBounds(10,10,100,20);
            text1.setBounds(120,10,100,20);

            lab2.setBounds(10,40,100,20);
            text2.setBounds(120,40,100,20);

            Table=new ArrayList();
        Table.add(new ArrayList());
        ((ArrayList)Table.get(0)).add("\nProgram Name   ");
        ((ArrayList)Table.get(0)).add("Count   ");
        ((ArrayList)Table.get(0)).add("Elapsed Time   ");
        ((ArrayList)Table.get(0)).add("Average ET\n");

        button.setBounds(120, 100, 100, 20);        

        button.addActionListener(new MyAction());

            Object[][] data = {
                {"Program Name","count","ET","Avg ET"}
            };


        model = new DefaultTableModel(data,columnNames);

            dataTable = new JTable(model);

            dataTable.setPreferredScrollableViewportSize(new Dimension(500, 70));
            dataTable.setFillsViewportHeight(true);

        dataTable.setBounds(220,130,300,200);
            f.add(lab1);
            f.add(text1);
            f.add(lab2);
            f.add(text2);

        f.add(dataTable);

        f.add(button);

            f.setVisible(true);
            f.setSize(300,350);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   
    }
}

在事件上我试图通过删除其以前的值来更新整个jtable.这是代码

model = new DefaultTableModel(data,columnNames);
dataTable.repaint();
dataTable=new JTable(model);

    dataTable.setPreferredScrollableViewportSize(new Dimension(500, 70));
    dataTable.setFillsViewportHeight(true);

dataTable.setBounds(220,130,300,200);

model.fireTableDataChanged();

数据是2d数组,列名是列.

但我没有JTable得到更新.

在我做错的地方,请给我一些指导.

Answer 1

您不想创建新的JTable,因为它对当前显示的JTable没有影响.相反,您希望调用setModel(...)当前的JTable并传入新的表模型.

此外,请处理您的代码格式,因为它是生硬的,它很臭.既然你要求志愿者付出努力来帮助你,我认为你没有太多要求你付出类似的努力来使你的代码难以阅读.

举个例子,检查哪个更易于阅读,上面的代码或此代码:

public class ChangeButtonLabel {
   private JTextField text1;
   private JButton button;
   private ArrayList Table;
   private JTextField text2;
   private Object[] columnNames;
   private DefaultTableModel model;
   private JTable dataTable;

   public ChangeButtonLabel() {
      JFrame f = new JFrame();
      f.setLayout(null);
      JLabel lab1 = new JLabel("Name");
      JLabel lab2 = new JLabel("Age");
      // table=new JTable(model);

      text1 = new JTextField(20);
      text2 = new JTextField(20);
      button = new JButton("OK");
      lab1.setBounds(10, 10, 100, 20);
      text1.setBounds(120, 10, 100, 20);
      lab2.setBounds(10, 40, 100, 20);
      text2.setBounds(120, 40, 100, 20);

      Table = new ArrayList();
      Table.add(new ArrayList());
      ((ArrayList) Table.get(0)).add("\nProgram Name   ");
      ((ArrayList) Table.get(0)).add("Count   ");
      ((ArrayList) Table.get(0)).add("Elapsed Time   ");
      ((ArrayList) Table.get(0)).add("Average ET\n");

      button.setBounds(120, 100, 100, 20);
      button.addActionListener(new MyAction());

      Object[][] data = { { "Program Name", "count", "ET", "Avg ET" } };
      model = new DefaultTableModel(data, columnNames);
      dataTable = new JTable(model);
      dataTable.setPreferredScrollableViewportSize(new Dimension(500, 70));
      dataTable.setFillsViewportHeight(true);
      dataTable.setBounds(220, 130, 300, 200);

      f.add(lab1);
      f.add(text1);
      f.add(lab2);
      f.add(text2);
      f.add(dataTable);
      f.add(button);
      f.setVisible(true);
      f.setSize(300, 350);
      f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   }
}

接下来我们将使用布局管理器......