Question

我有加载按钮，将数据加载到jtable
我可以将新数据加载到jtable 。

但是当我重新加载数据并点击jcheckbox时，会出现旧数据。 我正在使用defaulttablemodel选项。请运行编程并帮助我在哪里出错。

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;

public class MainWindow extends JFrame {
JTable table;
private static final int CHECK_COL = 3;
    String[] columnNames = {
    "Country", "Capital", "Population in Millions", "Democracy"};
    Object[][] data = {
    {"USA", "Washington DC", 280, false},
    {"Canada", "Ottawa", 32, false},
    {"United Kingdom", "London", 60, false},
    {"Germany", "Berlin", 83, false},
    {"France", "Paris", 60, false},
    {"Norway", "Oslo", 4.5, false},
    {"India", "New Deli", 1046, false}
    };
    DefaultTableModel dtm ;
    // static JScrollPane scrollpane= new JScrollPane();
    public MainWindow() {
    setTitle("Marking of data");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     JButton button1 = new JButton("load");
    button1.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        if(dtm!=null){
            System .out .println("NOT EMPTY");
            int c = dtm.getRowCount();
        // for (int i=c-1; i>=0; i--)
        // {
            // dtm.removeRow(i);
            // table.revalidate();
        // }
            loadtable();
             }
        if(dtm==null){
            System .out .println("EMPTY");
            loadtable();
        }
      }
      });

      JButton button = new JButton("check");
      button.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
        for (int row = 0; row < table.getRowCount(); row++) {
            Boolean b = ((Boolean) table.getValueAt(row, CHECK_COL));
            if (b.booleanValue()) {
                System.out.print("row " + row + " is " + b + ": ");
                for (int col = 0; col < table.getColumnCount(); col++) {
                    System.out.print(table.getValueAt(row, col) + " ");
                }
                System.out.println();
            }
        }
      }
      });
      JPanel buttonpanel1 = new JPanel();
      buttonpanel1.add(button1);
      JPanel buttonpanel = new JPanel();
      buttonpanel.add(button);
      add(buttonpanel, BorderLayout.SOUTH);
      add(buttonpanel1, BorderLayout.NORTH);
      pack();
      setLocationByPlatform(true);
      setVisible(true);
      }
      public void loadtable(){
    dtm = new DefaultTableModel(data, columnNames) {
        @Override
        public Class getColumnClass(int col) {
            return getValueAt(0, col).getClass();
        }
        @Override
        public boolean isCellEditable(int rowIndex, int colIndex) {
            return (colIndex == CHECK_COL);
        }
      };
      table = new JTable(dtm);
      JScrollPane scrollpane = new JScrollPane(table);
      add(scrollpane, BorderLayout.CENTER);
      pack();
      setVisible(true);
      }


     public static void main(String args[]) {
     EventQueue.invokeLater(new Runnable() {
     @Override
     public void run() {
        new MainWindow();
      }
     });
     }
      }

需要帮助。 PLS

Answer 1

默认表模型将二维数组中的数据复制到自己的向量中。

每次按下加载按钮，都会使用相同的数据创建一个新的默认表模型，并为新表模型的向量创建一个新副本。

每次按下加载按钮时，您的代码都会重置表模型，当然，旧数据会出现。

使用新数据刷新Jtable

1 个答案: