java - JTable/JScroll 隐藏行和 JTable

Question

您好，我是 JAVA 的新手，在学习时正在开发 GUI。我创建了一个带有 ScrollPane 和 JTable 的 JFrame。当我增加 2 列以上时，第一行下方的数据不会显示。

此外，当我的 JFram 出现时，屏幕是空白的，直到我重新调整窗口大小。

import javax.swing.*;
import javax.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.border.Border;
import javax.swing.JTable;
import javax.swing.JScrollPane;


public class Swing {

public static void main (String[] args){
//ADD FRAME 
    Color LBlue = new Color(83,141,213);//RGB Light BLUE

    JFrame frame = new JFrame("COLA");
    frame.setSize(950,350);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //CLOSE
    frame.getContentPane().setBackground(LBlue); //COLOR
    frame.setLocationRelativeTo(null); //Center JFrame in the middle of screen

//MENU Work
    JMenuBar menubar = new JMenuBar();
    frame.setJMenuBar(menubar);
    JMenu file = new JMenu ("File");
    menubar.add(file);
    JMenuItem exit = new JMenuItem("Exit");
    file.add(exit);

    class exitaction implements ActionListener{ //Action to call menu bar to close
        public void actionPerformed (ActionEvent o){
            System.exit(0);
        }
    }
    exit.addActionListener(new exitaction());
//GRID WORK

    JPanel panel = new JPanel(new GridBagLayout());
    frame.getContentPane().add(panel, BorderLayout.NORTH);
    GridBagConstraints c = new GridBagConstraints();
    panel.setBackground(LBlue); //Set Background of Panel
    panel.setVisible(true);


    String data[][] = {{"HEADER 1", "ABC"}, {"HEADER 1", "HEADER 1"}, {"HEADER     1", "GHI" },     {"HEADER 1", "GHI" }};
    String col[] = {"", "NAMES", "NAMES", };
    JTable table = new JTable(data, col);
    table.setBackground(Color.GRAY);
    table.setFont(new Font("Arial", Font.BOLD, 12));
    table.setVisible(true);

    JScrollPane scroll =new JScrollPane(table);
    c.gridx = 1; 
    c.gridy = 1;    
    scroll.setPreferredSize(new Dimension( 900,115));
    panel.add(scroll);

    table.revalidate();
    table.validate();
    table.repaint();
    table.setVisible(true);

    scroll.invalidate();
    scroll.validate();
    scroll.repaint();
    table.setVisible(true);

    frame.setVisible(true);

}

感谢您的帮助!

Answer 1

您的代码会生成堆栈跟踪

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 2
    at javax.swing.JTable$1.getValueAt(JTable.java:689)
    at javax.swing.JTable.getValueAt(JTable.java:2720)

这是问题的一个很好的指标。这意味着数据列的数量需要与列标识符的数量相匹配。添加缺失的数据:

String data[][] = { 
    { "NEWDATA", "HEADER 1", "ABC" }, { "NEWDATA", "HEADER 1", "HEADER 1" },
    { "NEWDATA", "HEADER     1", "GHI" }, { "NEWDATA", "HEADER 1", "GHI" }, 
};

阅读:How to Use Tables