您的问题是关于GridLayout的，但是您使用BorderLayout显示代码:

Your question is about GridLayout but you show code using BorderLayout:

buttonPanel = new JPanel(new BorderLayout());
button = new JButton("Display Color");
button.addActionListener(new ButtonListener ()); // Add event handler
button.setFont(font);
button.setPreferredSize(new Dimension(100, 100));

?

该按钮始终会填满整个面板，而如果我删除 gridlayout，该按钮将不会具有相同的行为.

The button always fills up the whole panel, whereas if I remove the gridlayout, the button won't have the same behavior.

这是GridLayout的默认行为，它的空间被平均分配，并且每个组件都占满了整个空间(BorderLayout会使用相同的空间).

This is GridLayout default behavior, it space is divided equally and each component takes up the full space (same would apply for BorderLayout).

还有许多其他LayoutManager可以满足您的需求:

There are many other LayoutManagers which will will meet your needs:

• 布局管理器的可视指南

您可能希望查看 GridBagLayout 更灵活:

You may want to look at GridBagLayout which is more flexible:

buttonPanel = new JPanel(new GridBagLayout());
button = new JButton("Display Color");
button.addActionListener(new ButtonListener()); // Add event handler
button.setFont(font);


GridBagConstraints gc=new GridBagConstraints();
gc.fill=GridBagConstraints.HORIZONTAL;
gc.gridx=0;
gc.gridy=0;
            
buttonPanel.add(button,gc);

，甚至是默认的JPanel FlowLayout:

    buttonPanel = new JPanel();
    button = new JButton("Display Color");
    button.addActionListener(new ButtonListener()); // Add event handler
    button.setFont(font);

    buttonPanel.add(button);

或第三方LayoutManger，例如 MigLayout .

Or a 3rd party LayoutManger like MigLayout.

其他建议

• 不要调用setPreferredSize(..)而不是覆盖getPreferredSize()，甚至不仅仅在绘制到Graphic s对象或想要使组件更大/更小时才这样做，不要出于布局目的而这么做，那就是

• Dont call setPreferredSize(..) rather override getPreferredSize() and even than only do this when painting to the Graphics object or wanting to make a component bigger/smaller dont do this for Layout purposes thats a LayoutManagers job.

还要始终记住在通过SwingUtilities.invokeLater(Runnable r)块