GridBagLayout 网格宽度无法按预期工作

Question

我正在使用 java swing LayoutManager GridBagLayout，遇到了这个问题。我想要这样的布局

ACC
BB

但是得到这样的布局

ACC
B

尽管 B 的网格宽度为 2，其中 A 的网格宽度为 1，但 A 和 B 占用的列数相同。我认为 A、B 和 C 之间不会有一个非常小的列，因为 C 从第 1 列开始。问题如果 C 的 gridwidth 是 1 而不是 2，则不会发生。我对输出感到困惑。

为什么会发生这种情况/我该如何解决？

JFrame test = new JFrame();
test.setSize(800,800);
test.setLayout(new GridBagLayout());
test.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

GridBagConstraints c;

c = new GridBagConstraints();
c.gridx=0;
c.gridy=0;
c.fill = GridBagConstraints.BOTH;
c.weightx = 1;
c.weighty = 1;
test.add(new JButton("A"), c);

c = new GridBagConstraints();
c.gridx=0;
c.gridy=2;
c.gridwidth=2;
c.fill = GridBagConstraints.BOTH;
c.weightx = 1;
c.weighty = 1;
test.add(new JButton("B"), c);

c = new GridBagConstraints();
c.gridx=1;
c.gridy=0;
c.gridwidth=2;
c.gridheight=2;
c.fill = GridBagConstraints.BOTH;
c.weightx = 2;
c.weighty = 2;
test.add(new JButton("C"), c);

test.setVisible(true);

Answer 1

我知道你的感受...GridBagLayout当列没有被 1x1 组件填充时，列的宽度似乎会减少到 0。我不知道以下是否是最有效的解决方案，但它有效（通过添加两个虚拟对象JPanel来“膨胀”第 1 列和第 2 列）：

JFrame test = new JFrame();
test.setSize(800,800);
test.setLayout(new GridBagLayout());
test.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

GridBagConstraints c;

c = new GridBagConstraints();
c.gridx=0;
c.gridy=0;
c.fill = GridBagConstraints.BOTH;
c.weightx = 1;
c.weighty = 1;
test.add(new JButton("A"), c);

c = new GridBagConstraints();
c.gridx=0;
c.gridy=1;
c.gridwidth=2;
c.fill = GridBagConstraints.BOTH;
c.weightx = 1;
c.weighty = 1;
test.add(new JButton("B"), c);

c = new GridBagConstraints();
c.gridx=1;
c.gridy=0;
c.gridwidth=2;
c.gridheight=1;
c.fill = GridBagConstraints.BOTH;
c.weightx = 2;
c.weighty = 2;
test.add(new JButton("C"), c);

c = new GridBagConstraints();
c.gridx=1;
c.gridy=2;
c.gridwidth=1;
c.gridheight=0;
c.fill = GridBagConstraints.HORIZONTAL;
c.weightx = 1;
c.weighty = 0;
test.add(new JPanel(), c);

c = new GridBagConstraints();
c.gridx=2;
c.gridy=3;
c.gridwidth=1;
c.gridheight=0;
c.fill = GridBagConstraints.HORIZONTAL;
c.weightx = 1;
c.weighty = 0;
test.add(new JPanel(), c);

test.setVisible(true);