如何让按钮用完 BorderLayout 中的所有 space，不留下白色 space？

Question

我有一个程序可以创建一个用随机颜色填充的 8x8 网格（已经完成了这一点），我应该在底部添加一个按钮，它应该填充整个底部，用于重置颜色。我已经有了网格和按钮，但是，我的按钮并没有填满底部的整个 space，只有大约一半。如何让它填满整个 space？

我的代码：

public void createGUI() 
{
    guiFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    guiFrame.setTitle("Label demo");
    JPanel mainPanel = new JPanel();
    JPanel gridPanel = new JPanel();
    JPanel buttonPanel = new JPanel();
    JButton refreshButton = new JButton("Press me to refresh labels");
    mainPanel.setLayout(new BorderLayout());
    guiFrame.getContentPane().add(mainPanel);
    gridPanel.setLayout(new GridLayout(8, 8));
    for (int i = 0; i < arrayLabels.length; i++)
    {
        arrayLabels[i] = new ColorLabel(80, 80, new Color(rand.nextInt()), 0, new Color(rand.nextInt()));
    }

    for (int i = 0; i < 8*8; i++)
    {
        gridPanel.add(arrayLabels[i]);
    }
    guiFrame.getContentPane().add(gridPanel);
    buttonPanel.add(refreshButton);
    guiFrame.getContentPane().add(buttonPanel, BorderLayout.SOUTH);
    guiFrame.setVisible(true);
}

我的程序目前的输出是这样的：https://imgur.com/a/fw1Bx92

Answer 1

同时设置刷新按钮的JPanel布局！下面我举个例子大家可以看看：

public static void createGUI() 
{
    JFrame guiFrame = new JFrame("a");
    guiFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    guiFrame.setTitle("Label demo");
    JPanel mainPanel = new JPanel();
    JPanel gridPanel = new JPanel();
    JPanel buttonPanel = new JPanel(new BorderLayout());
    JButton refreshButton = new JButton("Press me to refresh labels");
    mainPanel.setLayout(new BorderLayout());
    guiFrame.getContentPane().add(mainPanel);
    gridPanel.setLayout(new GridLayout(8, 8));
    JLabel arrayLabels[] = new JLabel[64];
    for (int i = 0; i < 64; i++)
    {
        arrayLabels[i] = new JLabel("a");
    }

    for (int i = 0; i < 8*8; i++)
    {
        gridPanel.add(arrayLabels[i]);
    }
    guiFrame.getContentPane().setLayout(new BorderLayout());
    guiFrame.getContentPane().add(gridPanel,BorderLayout.CENTER);
    buttonPanel.add(refreshButton,BorderLayout.CENTER);
    guiFrame.getContentPane().add(buttonPanel, BorderLayout.SOUTH);
    guiFrame.setVisible(true);
}

如何让按钮用完 BorderLayout 中的所有 space，不留下白色 space？

How do I make a button use up all of the space within a BorderLayout leaving no white space?

java

user-interface

swing

layout-manager

border-layout