相关疑难解决方法(0)

嗨伙计们希望你能帮到我这里,我的代码(逻辑方面)很好唯一的问题是列标题没有显示在2个表格中(表格和表格,一个用于教师,一个用于学生详细信息) )我怎么让它们显示？

        import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;


public class Display
{
    ArrayList<Student> stud1 = new ArrayList<Student>();
    ArrayList<SubjectTeacher> sTeach1 = new ArrayList<SubjectTeacher>();

    //For Display Teachers
    private  JTable table;
    private  JFrame f;
    private int i;

    //For DisplayStudents
    private JTable tableS;
    private JFrame fS;
    private int iS;


    //Displays Teachers
    public void displayTeachers()
    {

            f = new JFrame("Teachers");

            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            f.setSize(500,400);
            f.setVisible(true);



        String[] columnNames =  {"Name", "Surname", "ID", "Pay", "Subject"};

        sTeach1 = Stores.getTeach();
        i = sTeach1.size();


        Object[][] data = new …

我今天面对这个新事物,我不知道为什么.例如,当我想在面板中显示某些内容时,我只需将其添加到面板中; 但为什么我不能直接添加表格滚动窗格,为什么我必须调用该setviewportview()方法？是什么add()方法做的又是什么setViewProtView()呢？

这是我的代码:

public class DownloadMainView extends JFrame{
    private ArrayList<DownloadItem> downloadList = new ArrayList<DownloadItem>();
    private JMenuBar menubar = new JMenuBar();
    private JMenu m_task = new JMenu("Tasks");
    private JMenu m_tool = new JMenu("Tools");
    private JMenu m_help = new JMenu("Help");

    private JMenuItem mi_add = new JMenuItem("Add");
    private JMenuItem mi_exit = new JMenuItem("Exit");
    private JMenuItem mi_options = new JMenuItem("Options");
    private JMenuItem mi_help = new JMenuItem("Help");
    private JMenuItem mi_about = new JMenuItem("About");

    private JTree categoryTree = new JTree();
    private JTable contentTable = new JTable(new Object[][]{},new Object[]{"No.","Filename","URL","Status","Size","Added …

我使用以下代码创建JTable内部JScrollPane以显示列标题

JTable不会显示列标题

String[] columnNames = {"header1", "header2", "header2", "header3"};
Object[][] data = new Object[num][4];
//feed values into data using for

JTable chart = new JTable(data, columnNames);
chart.setShowVerticalLines(false);
chart.setEnabled(false);
chart.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);

JScrollPane sp = new JScrollPane(chart);
sp.setPreferredSize(new Dimension(width, chart.getHeight() + 5));
panel.add(sp);

问题是我需要计算一个高度,JScrollPane这样整体JTable就可以看到而且JScrollBar不会出现.我怎样才能做到这一点？

num从2更改为4,如果是4,则会出现滚动条. width是固定的.

下面是我的代码。尽管我使用的是 Oracle 网站上提供的代码，但它显示行数据但不显示列名

JPanel panel = new JPanel(new GridLayout(1, 1));
            JTextField txtFilter = new JTextField("1234.56");
            //panel.add(txtFilter);
            //TableModel model = new BibTexModel();
           String[] columnNames = {
                            "First Name",
                            "Last Name",
                            "Sport",
                            "# of Years",
                            "Vegetarian"
             };
           Object[][] data = {
                {"Kathy", "Smith",
                 "Snowboarding", new Integer(5), new Boolean(false)},
                {"John", "Doe",
                 "Rowing", new Integer(3), new Boolean(true)},
                {"Sue", "Black",
                 "Knitting", new Integer(2), new Boolean(false)},
                {"Jane", "White",
                 "Speed reading", new Integer(20), new Boolean(true)},
                {"Joe", "Brown",
                 "Pool", new Integer(10), new Boolean(false)}
};
            JTable table = new …

可能重复:
JTable不会显示列标题
如何查看JTable中的列标签？

我正在使用swing创建用户注册表单.某些标签显示不正确,也不显示列名.

以下是我的代码:

import java.awt.EventQueue;

import javax.swing.JFrame;
import java.awt.FlowLayout;
import javax.swing.JLabel;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import javax.swing.JTextField;
import java.awt.Insets;
import javax.swing.JComboBox;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JCheckBox;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
import javax.swing.GroupLayout;
import javax.swing.GroupLayout.Alignment;
import javax.swing.LayoutStyle.ComponentPlacement;
import java.awt.Font;
import javax.swing.JButton;
import java.awt.Window.Type;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JScrollBar;
import java.awt.Scrollbar;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Vector;

import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;
import javax.swing.ListSelectionModel;


public class UserRegistration {

    private …