Question

我有JPanel GridBagLayout。该面板包含2行，第一行有一个JLabel，第二行有一个JScrollPane，里面有JTable。该表未填充100％的滚动窗格。即使我调整框架大小，滚动窗格也会调整大小，但内部的桌子总是有固定的宽度。

JTable table=new JTable(myModel);
table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF); 
JScrollPane scroll=new JScrollPane(table);

JPanel panel=new JPanel(new GridBagLayout());
// component add details skipped

以下是添加到面板时应用于滚动窗格的网格包约束。

GridBagConstraints gbc=new GridBagConstraints();
gbc.gridx=0; // first column
gbc.gridy=1; // second row
gbc.gridwidth=1;
gbc.gridheight=1;
gbc.fill=GridBagConstraints.BOTH;
gbc.anchor=GridBagConstraints.NORTHEAST;
gbc.weightx=1.0;
gbc.weighty=1.0;

出了什么问题？滚动窗格或表格有问题吗？

Answer 1

我认为只是（通知行永远不会通过使用任何LayoutManager来调整大小）

c.fill = GridBagConstraints.BOTH;
c.weightx = 1;
c.weighty = 0;

GBC不适合JComponents的LayoutManager实现Scrollable，对这些JComponents使用BorderLayout（ev GridLayout）

例如

import java.awt.*;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;

public class JTableAndGBC {

    private String[] columnNames = {"Source", "Hit", "Last", "Ur_Diff"};
    private JTable table;
    private Object[][] data = {{"Swing Timer", 2.99, 5, 1.01},
        {"Swing Worker", 7.10, 5, 1.010}, {"TableModelListener", 25.05, 5, 1.01}};
    private DefaultTableModel model = new DefaultTableModel(data, columnNames);

    public JTableAndGBC() {
        JPanel panel = new JPanel(new GridBagLayout());
        table = new JTable(model);
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.weightx = 1.0;
        gbc.fill = GridBagConstraints.HORIZONTAL;
        panel.add(table, gbc);
        JFrame frame = new JFrame();
        frame.add(panel, BorderLayout.CENTER);
        frame.pack();
        frame.setVisible(true);
    }

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

编辑1

JTable，JScollPane，JComboBox无法返回合理的PreferredSize，请参阅编辑中的代码，然后查看所有LayoutManagers的内容，
小心注意table.setPreferredScrollableViewportSize(table.getPreferredSize());，我建议测试Dimension是否超载所需坐标或屏幕分辨率或不过载:-),
否则缩小new Dimension(int, int)代替table.getPreferredSize()

import java.awt.*;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;

public class JTableAndGBC {

    private String[] columnNames = {"Source", "Hit", "Last", "Ur_Diff"};
    private JTable table;
    private Object[][] data = {{"Swing Timer", 2.99, 5, 1.01},
        {"Swing Worker", 7.10, 5, 1.010}, {"TableModelListener", 25.05, 5, 1.01}};
    private DefaultTableModel model = new DefaultTableModel(data, columnNames);

    public JTableAndGBC() {
        JPanel panel = new JPanel(new GridBagLayout());
        table = new JTable(model);
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.weightx = 1.0;
        gbc.fill = GridBagConstraints.HORIZONTAL;
        JScrollPane pane = new JScrollPane(table);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        panel.add(pane, gbc);
        JFrame frame = new JFrame();
        frame.add(panel, BorderLayout.CENTER);
        frame.pack();
        frame.setVisible(true);
    }

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

编辑2

我强烈建议使用BorderLayout，GridLayout

enter image description here

而不是GBC（JTable，JScollPane，JComboBox无法返回合理的PreferredSize，需要覆盖GBC，brrrr，这不是为什么要打扰）

enter image description here 。

BorderLayout的代码

import java.awt.*;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;

public class JTableAndGBC {

    private String[] columnNames = {"Source", "Hit", "Last", "Ur_Diff"};
    private JTable table;
    private Object[][] data = {{"Swing Timer", 2.99, 5, 1.01},
        {"Swing Worker", 7.10, 5, 1.010}, {"TableModelListener", 25.05, 5, 1.01}};
    private DefaultTableModel model = new DefaultTableModel(data, columnNames);

    public JTableAndGBC() {
        JPanel panel = new JPanel(new BorderLayout()/*(new GridBagLayout()*/);
        table = new JTable(model);
        //GridBagConstraints gbc = new GridBagConstraints();
        //gbc.weightx = 1.0;
        //gbc.fill = GridBagConstraints.HORIZONTAL;
        JScrollPane pane = new JScrollPane(table, 
                ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
                ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
        /*TableColumn firstColumn = table.getColumnModel().getColumn(0);
        firstColumn.setMinWidth(150);
        firstColumn.setMaxWidth(200);
        TableColumn secondColumn = table.getColumnModel().getColumn(1);
        secondColumn.setMinWidth(200);
        secondColumn.setMaxWidth(250);
        TableColumn thirdColumn = table.getColumnModel().getColumn(1);
        thirdColumn.setMinWidth(50);
        thirdColumn.setMaxWidth(100);   */     
        table.setRowHeight(30);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        panel.add(pane/*, gbc*/);
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(panel, BorderLayout.CENTER);
        frame.pack();
        frame.setVisible(true);
    }

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

Answer 2

感谢您提供宝贵的建议。我找到了解决这个问题的确切方法。将表格调整为首选大小或查看端口大小，以较大者为准。无论您使用何种布局管理器，它都能正常工作！

解决方案是使用getScrollableTracksViewportWidth()方法定义的表，如下所示：

JTable table=new JTable(myModel){
 public boolean getScrollableTracksViewportWidth() {
   return getPreferredSize().width < getParent().getWidth();
 }
};
JScrollPane scroll=new JScrollPane(table);

Answer 3

删除

table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);

线。它会导致固定的表格大小。

JTable没有填充使用GridBagLayout添加到JPanel的JScrollPane

3 个答案: