java - 在 JTable 中添加第二行时删除第一行

Question

我有一个 JtextField 和 Jcombobox。每当从文本字段和组合框中选择值并单击添加按钮时，值应该出现在表中。第一行已正确添加。当我尝试添加第二行时，第一行值被替换为新值，但不添加第二行。每次单击“添加”按钮时，都应将值添加到表中，而不删除旧值，并且单击“删除”时，我应该能够删除该行..我该如何实现这一点。这是我的代码

public static void main(String[] args) 
{
    // TODO Auto-generated method stub
   EventQueue.invokeLater(new Runnable() {

    @Override
    public void run() {
        // TODO Auto-generated method stub
        try
        {
        ModelSelection modelselection=new ModelSelection();
        modelselection.setVisible(true);
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
});

}

public ModelSelection() throws TooManyListenersException
{
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setResizable(false);
    setBounds(240, 30, 906, 658);
    contentPane =new JPanel();
    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    setContentPane(contentPane);
    Image im=new ImageIcon(this.getClass().getResource("/sprinkle.jpg")).getImage();
    setContentPane(new JLabel(new ImageIcon(im)));
    contentPane.setLayout(null);                

    modelSelection=new JLabel("MODULE SELECTION");
    modelSelection.setBounds(240, 20, 450,40);
    modelSelection.setFont(new Font("arial",Font.BOLD,40));
    Color modellabel = new Color(16,180,205);
    modelSelection.setForeground(modellabel);
    add(modelSelection);


    lab=new JLabel("Choose S-NET device and S-NET ID");
    lab.setBounds(30, 75, 500,40);
    lab.setFont(new Font("arial",Font.BOLD,25));
    Color label = new Color(176,224,230);
    lab.setForeground(label);
    add(lab);

    choice=new JLabel("S-Net Device    -");
    choice.setBounds(30, 145, 200, 20);
    choice.setFont(new Font("arial",Font.BOLD,25));
    Color choicecolor = new Color(135,206,250);
    choice.setForeground(choicecolor);      
    add(choice);

    String devicesnames[]={"SW-LE-4","SD-LD-4","SR-RL-8","SD-FL-4","SD-FN-2"};
    mod=new JComboBox(devicesnames);
    mod.setBounds(260,140,230,35);
    Color modcolor = new Color(173,216,230);
    mod.setBackground(modcolor);    
    mod.setFont(new Font("arial",Font.BOLD,17));
    Color border=new Color(30,144,255);
    mod.setBorder(new LineBorder(border, 2));
    mod.setSelectedIndex(-1);
    add(mod);

    snet=new JLabel("S-Net ID            -");
    snet.setBounds(30, 200, 200, 20);
    snet.setFont(new Font("arial",Font.BOLD,25));
    Color snetcolor = new Color(135,206,250);
    snet.setForeground(snetcolor);      
    add(snet);  

    id=new JTextField("1");
    id.setBounds(260,200,230,35);
    id.setEditable(true);
    Color idcolor = new Color(173,216,230);
    id.setBackground(idcolor);  
    Color idborder=new Color(30,144,255);
    id.setBorder(new LineBorder(idborder, 3));
    id.setFont(new Font("arial",Font.BOLD,20));
    add(id);

    validityid=new JLabel("**S-Net ID(1-230) only");
    validityid.setBounds(500, 210, 200, 20);
    validityid.setFont(new Font("arial",Font.PLAIN,18));
    Color validityidcolor = new Color(255,99,71);
    validityid.setForeground(validityidcolor);      
    add(validityid);    


    add=new JButton("ADD");
    add.setBounds(180,260, 80, 35);
    Color addbackground=new Color(0,0,255);
    add.setBackground(addbackground);           
    Color border1=new Color(30,144,255);
    add.setBorder(new LineBorder(border1,3));   
    add.setFont(new Font("arial",Font.BOLD,18));
    add.setForeground(Color.WHITE);
    add.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) 
        {
            // TODO Auto-generated method stub
            if(mod.getSelectedItem()!=null && id.getText()!=null)
            {
                System.out.println("correct");
                simpleset();
            }
            else
            {
                JOptionPane optionPane = new JOptionPane("Fields cannot be empty", JOptionPane.ERROR_MESSAGE);
                 JDialog dialog = optionPane.createDialog("FAILURE");
                 dialog.setAlwaysOnTop(true);
                 dialog.setVisible(true);
            }
        }
    });
    add(add);

    devices=new JLabel("Selected S-NET device and S-NET ID");
    devices.setBounds(30, 310, 450,40);
    devices.setFont(new Font("arial",Font.BOLD,25));
    Color deviceslabel = new Color(176,224,230);
    devices.setForeground(deviceslabel);
    add(devices);


    String columnNames[] = { "S-NET Device","S-NET ID"};
    String dataValues[][] =
    { 
        { "12", "234", },
        { "-123", "43",  },
        { "93", "89.2",  },
        { "12", "234", },
        { "-123", "43",  },


    };

    t=new JTable();
    JScrollPane s=new JScrollPane(t);
    s.setBounds(30, 360, 400, 200);
    Color sbcolor = new Color(128,200,242);
    t.setBackground(sbcolor);
    Color headercolor = new Color(152,252,252);
    t.getTableHeader().setBackground(headercolor);
    Color headerborder=new Color(0,0,255);
    t.getTableHeader().setBorder(new LineBorder(headerborder,2));
    t.getTableHeader().setFont(new Font("arial", Font.BOLD, 18));
    t.setRowHeight(30);
    t.setFillsViewportHeight(true);
    t.setShowVerticalLines(true);
    t.setShowGrid(true);
    Color gridcolor=new Color(0,0,0);
    t.setGridColor(gridcolor);
    t.setFont(new Font("arial", Font.BOLD, 17));       
    Color scrollborder=new Color(15,132,210);
    s.setBorder(new LineBorder(scrollborder, 4));
    s.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);
    add(s);


    configure=new JButton("CONFIGURE");
    configure.setBounds(80,575, 120, 35);       
    Color configureborder=new Color(30,144,255);
    configure.setBorder(new LineBorder(configureborder, 3));
    Color configurebackground=new Color(50,205,50);
    configure.setBackground(configurebackground);
    configure.setFont(new Font("arial",Font.BOLD,15));
    configure.setForeground(Color.WHITE);
    add(configure);
    delete=new JButton("DELETE");
    delete.setBounds(230,575, 120, 35);       
    Color deleteborder=new Color(30,144,255);
    delete.setBorder(new LineBorder(deleteborder, 3));
    Color deletebackground=new Color(220,20,60);
    delete.setBackground(deletebackground);
    delete.setFont(new Font("arial",Font.BOLD,15));
    delete.setForeground(Color.WHITE);
    add(delete);



}   

protected void simpleset() 
{
    // TODO Auto-generated method stub
    String data=mod.getSelectedItem().toString();
    System.out.println(data);

    String num=id.getText();


    String columnNames[] = { "S-NET Device","S-NET ID"};
    Object[][] row={{data,num}};
    for(int i=0;i<row.length;i++)
    {
    System.out.println(row[i]);
    }

     DefaultTableModel dtm = new DefaultTableModel(0, 0);   
     dtm.setColumnIdentifiers(columnNames);    

     List<String> list = new ArrayList<String>();

     list.add(num);
     list.add(data);

     dtm.addRow(list.toArray());

     t.setModel(dtm);             
    DefaultTableCellRenderer rightRenderer=new DefaultTableCellRenderer();                                             
    rightRenderer.setHorizontalAlignment(SwingConstants.CENTER);
    t.getColumnModel().getColumn(0).setCellRenderer(rightRenderer);
    t.getColumnModel().getColumn(1).setCellRenderer(rightRenderer);         



}

Answer 1

您的 simpleset() 在每次调用时重新创建 TableModel。

DefaultTableModel dtm = new DefaultTableModel(0, 0);
...
t.setModel(dtm); 

只需创建一次，存储为字段(或从 JTable 实例获取)并使用 addRow() 或 insertRow() 方法插入新数据。