Question

我正在使用GridBagLayout来设计界面。界面在北方设置了一个JTabbedPane，在我调整大小时填充了两个方向，在JTabbedPane下方有两个JButton s。

我想要实现的是将这两个按钮放在东并使用仅 GridBagLayout功能（不引入额外的JPanel），但我没有这样做。

| - [标签] -------------------------- |
| --------------------------------- |
| --------------------------------- |
| --------------------------------- |
| --------------------------------- |
| ------------- [按钮] [按钮] |

当我将两个按钮的布局约束设置为WEST（而不是EAST）时。两个都正确地向西走了！

c.anchor = GridBagConstraints.WEST;

但是当我将两个按钮的布局约束设置为东

时

c.anchor = GridBagConstraints.EAST;

其中一人往东走，另一人往西走！

要解决此问题，我添加了JPanel，其中包含两个按钮并将此JPanel添加到界面中，并将其布局约束设置为c.anchor = GridBagConstraints.EAST;。效果很好。

但是，是否可以在不使用额外GridBagLayout作为容器的情况下构建相同的JPanel界面？

以下两个类格式为 SSCCE ;第一个显示问题 GridBagTest ，另一个显示使用额外GridBagTest_solved JPanel >

问题类：

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

public class GridBagTest extends JPanel {

    JFrame frame;
    JTabbedPane tabbedPane;
    JPanel panel_tab;

    JButton btn_previous;
    JButton btn_next;

    private void create_and_layout() {

        this.setLayout(new GridBagLayout());

        tabbedPane = new JTabbedPane() {
            @Override
            public Dimension getPreferredSize() {
                return new Dimension(300, 150);
            }
        };

        panel_tab = new JPanel();
        tabbedPane.addTab("Tab 1", panel_tab);

        btn_previous = new JButton("previous");
        btn_next = new JButton("  next  ");

        GridBagConstraints c;

        c = new GridBagConstraints();
        c.gridx = 0;
        c.gridy = 0;
        c.weightx = 1;
        c.gridwidth = 2;
        c.weighty = 1;
        c.fill = GridBagConstraints.BOTH;
        c.anchor = GridBagConstraints.NORTH;
        this.add(tabbedPane, c);

        c = new GridBagConstraints();
        c.gridx = 0;
        c.gridy = 1;
        c.anchor = GridBagConstraints.EAST;
        c.insets = new Insets(2, 0, 2, 2);
        this.add(btn_previous, c);

        c = new GridBagConstraints();
        c.gridx = 1;
        c.gridy = 1;
        c.anchor = GridBagConstraints.EAST;
        c.insets = new Insets(2, 0, 2, 2);
        this.add(btn_next, c);
    }

    private void initGUI() {
        create_and_layout();
        frame = new JFrame("GridBagTest");
        frame.getContentPane().add(this);
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        java.awt.EventQueue.invokeLater(new GridBagTest()::initGUI);
    }
}

解决方案类：

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

public class GridBagTest_solved extends JPanel {

    JFrame frame;
    JTabbedPane tabbedPane;
    JPanel panel_tab;
    JPanel panel_buttons;

    JButton btn_previous;
    JButton btn_next;

    private void create_and_layout() {

        this.setLayout(new GridBagLayout());

        tabbedPane = new JTabbedPane() {
            @Override
            public Dimension getPreferredSize() {
                return new Dimension(300, 150);
            }
        };

        panel_tab = new JPanel();
        tabbedPane.addTab("Tab 1", panel_tab);

        panel_buttons = new JPanel(new GridBagLayout());

        btn_previous = new JButton("previous");
        btn_next = new JButton("  next  ");

        GridBagConstraints c;
        // Adding buttons to panel_buttons
        c = new GridBagConstraints();
        c.gridx = 0;
        c.gridy = 0;
        c.insets = new Insets(2, 0, 2, 2);
        panel_buttons.add(btn_previous, c);

        c = new GridBagConstraints();
        c.gridx = 1;
        c.gridy = 0;
        c.insets = new Insets(2, 0, 2, 2);
        panel_buttons.add(btn_next, c);

        // Adding tabbedPane & panel_buttons to this (GridBagTest_solved)
        c = new GridBagConstraints();
        c.gridx = 0;
        c.gridy = 0;
        c.weightx = 1;
        c.weighty = 1;
        c.fill = GridBagConstraints.BOTH;
        c.anchor = GridBagConstraints.NORTH;
        this.add(tabbedPane, c);

        c = new GridBagConstraints();
        c.gridx = 0;
        c.gridy = 1;
        c.anchor = GridBagConstraints.EAST;
        this.add(panel_buttons, c);
    }

    private void initGUI() {
        create_and_layout();
        frame = new JFrame("GridBagTest_solved");
        frame.getContentPane().add(this);
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        java.awt.EventQueue.invokeLater(new GridBagTest_solved()::initGUI);
    }
}

Answer 1

如果你只有三个组件--JTabbedPane和两个JButton，你应该考虑使用比GridBag更简单的布局。只需使用BorderLayout作为主面板，将JTabbedPane放在CENTER中，将一个JPanel放在一个具有TRAILING对齐的FlowLayout的JP中，然后将两个按钮添加到该JPanel。

是否可以构建相同的GridBagLayout接口但不使用额外的JPanel作为容器？

1 个答案: