如何从 JTable 的底部删除多余的白色 space？

Question

我编写了一个创建空 JTable 的简单程序。但是当我显示 Table 时，在 Table.Now 下面可以看到一个额外的白色 space 我想删除 table.[= 行下面的那个白色 space 12=]

JTable 程序:

public class Table extends JFrame {

Table() 
{
      int numColoumns=5;
      int numRows=10 ;
      String[] colHeadings = {"COLUMN1","COLUMN2","COLUMN3","COLUMN4","COLUMN5"};

      DefaultTableModel model = new DefaultTableModel(numRows, numColoumns) ;
      model.setColumnIdentifiers(colHeadings);

      JTable table = new JTable(model);
      JTableHeader head = table.getTableHeader();

      Container c = getContentPane();
      c.setLayout(new BorderLayout());
      c.add("North", head);
      c.add("Center",table);
}       
public static void main(String[] args) throws NumberFormatException, IOException
{
    Table t = new Table();
    t.setSize(500,400);
    t.setVisible(true);
    t.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}}

程序给了我一个table，但是行没有完全填到window。它显示一个 window，具有给定的高度和宽度（以像素为单位）以及创建的相应行数 rows.Below 它显示额外的 space，因为这些行未填充到 window。谁能帮我从 window 中删除多余的 space。

抱歉，我创建了输出图像，但上传图像时出现问题。

Answer 1

如图所示 , you can override the Scrollable method getPreferredScrollableViewportSize() to return a value that reflects your initial desired row count. Each time a row is added, pack() 封闭 window，其中 "Causes this Window to be sized to fit the preferred size and layouts of its subcomponents."

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;

/**
 * @see 
 * @see 
 */
public class Test {

    private void display() {
        JFrame f = new JFrame("Test");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        class MyTableModel extends AbstractTableModel {

            private int n = 8;

            private void addRow() {
                n++;
                fireTableRowsInserted(n - 1, n - 1);
            }

            @Override
            public int getRowCount() {
                return n;
            }

            @Override
            public int getColumnCount() {
                return 4;
            }

            @Override
            public Object getValueAt(int rowIndex, int colIndex) {
                return "R" + rowIndex + ":C" + colIndex;
            }
        };
        MyTableModel model = new MyTableModel();
        JTable table = new JTable(model) {
            @Override
            public Dimension getPreferredScrollableViewportSize() {
                return new Dimension(super.getPreferredSize().width,
                    getRowHeight() * getRowCount());
            }
        };
        table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
        f.add(new JScrollPane(table));
        f.add(new JButton(new AbstractAction("Add Row") {
            @Override
            public void actionPerformed(ActionEvent e) {
                model.addRow();
                f.pack();
            }
        }), BorderLayout.SOUTH);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Test()::display);
    }
}

如何从 JTable 的底部删除多余的白色 space？

How to remove extra white space from the bottom of the JTable?

java

swing

jtable

jscrollpane