使用JScrollPane添加JTable后，JTable不可见。

Question

我正在开发一个基于GUI的项目，需要在JPanel中添加一个JTable。但是当使用滚动窗格添加时，无法显示表格。而且当不使用滚动窗格添加时，表头也无法显示。谢谢任何帮助......以下是我正在使用的代码：

import javax.swing.*;
import javax.swing.table.*;
import java.sql.*;
import java.awt.*;
import java.awt.event.*;

public class FrmAddEditDN extends JDialog{
    JButton JBUpdate = new JButton(new ImageIcon("images/save.png"));
    JButton JBReset = new JButton("Reset",new ImageIcon("images/reset.png"));
    JButton JBCancel = new JButton("Cancel",new ImageIcon("images/cancel.png"));

    JLabel JLPic1 = new JLabel();
    JLabel JLBanner = new JLabel("Please fill-up all the required fields.");

public FrmAddEditDN(boolean ADD_STATE,JFrame OwnerForm,Connection srcCN,String srcSQL){
        super(OwnerForm,true);
        cnAEDN = srcCN;
        ADDING_STATE = ADD_STATE;
        JPanel JPContainer = new JPanel();
        JPContainer.setLayout(null);
                String[] columnNames = {
                    "Sr No","Invoice No","Invoice Date","Consignee","Description","Basic Amount","Invoice Amount","Payment Received",
                "EFT Date","Payment Earlier Received","Comm. @ %","Comm.Claim @ %","Comm. Received","Date","Bank","Remarks"};
                String[][] data = {
                    {"","","","","","","","","","","","","","","",""}
   };
                DefaultTableModel DTModel = new DefaultTableModel(data,columnNames);
                JTable table = new JTable(5,16);
                table.setBounds(15,295,screen.width-40,150);
                table.setRowHeight(30);
                table.setForeground(Color.black);
                table.setBackground(Color.white);
                JTableHeader header = table.getTableHeader();
                header.setForeground(Color.red);
                header.setBackground(Color.green);
                table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
                table.getColumnModel().getColumn(0).setPreferredWidth(2);
                table.getColumnModel().getColumn(1).setPreferredWidth(50);
                JScrollPane tableContainer = new JScrollPane();
                tableContainer.setViewportView(table);

                JPContainer.add(tableContainer);

                getContentPane().add(JPContainer);
        setSize(screen.width-5,screen.height-45);
        setResizable(false);
        setLocation(0,0);
    }
}

- user1718945

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当未添加到滚动窗格时，您需要手动添加表头。这在JTable类的Java文档中有提到。 - Robin

Answer 1

在创建JScrollPane时，需要传递Component。

JScrollPane scrollPane = new JScrollPane(table);
JPContainer.add(scrollPane);

- KV Prajapati

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那么，使用 JScrollPane 的 add() 方法的目的是什么呢？我尝试像上面的例子一样使用 **scrollPane.add(table)**，但它没有起作用。我们应该在什么时候使用 JScrollPane 的 add() 方法呢？ - amin__

@amin__ 这只是从父类（Container）继承而来的，我猜不幸的是它不能像我们期望的那样在JScrollPane上工作。 - Line

@Line 那是半个十年前的事了。让我感到很怀旧。不过还是谢谢你的回答。 - amin__