Swing Button Invisible直到actionPerformed

Question

是否可以创建一个在用户点击另一个按钮之前不会被看到的按钮？

我的目标是默认情况下按钮不可见，而不是点击时按钮。然后在执行另一个操作时变得可见。下面的代码是我创建此代码的原始尝试。

public void but_roll1ActionPerformed(java.awt.event.ActionEvent evt) 
{
    if (!bal_but.isEnabled() && !gamble_but.isEnabled()) {
        but_roll1.setVisible(true);
        but_roll1.setEnabled(true);         
        d1 = diceRoll();
        die1_display.setText(String.valueOf(d1));  
        but_roll1.setEnabled(false);
    } else {
        but_roll1.setVisible(false);
    }
}  

Answer 1

两个更好的策略：

1. 将按钮放在带有第二个空白面板的CardLayout中，直到需要为止。
2. 禁用按钮，直到单击第一个按钮。

我更喜欢第二个作为用户的“最少惊喜之路”。 YMMV。

初始视图



在“效果”按钮操作后查看



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

public class ButtonNotUsableTillAction {

    private JComponent ui = null;

    ButtonNotUsableTillAction() {
        initUI();
    }

    public void initUI() {
        if (ui!=null) return;

        ui = new JPanel(new GridLayout(1, 0, 4, 4));
        ui.setBorder(new EmptyBorder(4,4,4,4));

        // first demo, using card layout
        JPanel cardDemoPanel = new JPanel(new GridLayout(1, 0, 2, 2));
        cardDemoPanel.setBorder(new TitledBorder("Card Layout"));
        ui.add(cardDemoPanel);

        JButton actionCardButton = new JButton("Action");
        cardDemoPanel.add(actionCardButton);

        CardLayout cardLayout = new CardLayout();
        JPanel cardLayoutPanel = new JPanel(cardLayout);
        cardDemoPanel.add(cardLayoutPanel);
        cardLayoutPanel.add(new JPanel(), "panel");
        cardLayoutPanel.add(new JButton("Effect"), "button");
        cardLayout.show(cardLayoutPanel, "panel");

        ActionListener flipCardListener = new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                cardLayout.show(cardLayoutPanel, "button");
            }
        };
        actionCardButton.addActionListener(flipCardListener);

        // first demo, using disabled / enabled
        JPanel enabledDemoPanel = new JPanel(new GridLayout(1, 0, 2, 2));
        enabledDemoPanel.setBorder(new TitledBorder("Enabled"));
        ui.add(enabledDemoPanel);
        JButton actionEnabledButton = new JButton("Action");
        enabledDemoPanel.add(actionEnabledButton);
        JButton effectButton = new JButton("Effect");
        enabledDemoPanel.add(effectButton);
        effectButton.setEnabled(false);
        ActionListener enableComponentListener = new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                effectButton.setEnabled(true);
            }
        };
        actionEnabledButton.addActionListener(enableComponentListener);
    }

    public JComponent getUI() {
        return ui;
    }

    public static void main(String[] args) {
        Runnable r = new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (Exception useDefault) {
                }
                ButtonNotUsableTillAction o = new ButtonNotUsableTillAction();

                JFrame f = new JFrame(o.getClass().getSimpleName());
                f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                f.setLocationByPlatform(true);

                f.setContentPane(o.getUI());
                f.pack();
                f.setMinimumSize(f.getSize());

                f.setVisible(true);
            }
        };
        SwingUtilities.invokeLater(r);
    }
}

Answer 2

正如@markspace所提到的，您需要在设置按钮可见后重新验证按钮的容器：

but_roll1.getParent().revalidate();