如何使滚动按钮默认允许按回车键？

Question

我编写了一个程序来随机 select 一张图像，并在每次按下按钮时将其显示在 window 中。我正在尝试弄清楚如何使 "Roll Dice" 按钮成为允许按回车键的默认按钮。

Driver:

public class MCobbM10A1 {

    static int SCREEN_WIDTH = 500;
    static int SCREEN_HEIGHT = 600;
    static WidgetPanel widget;
    static GraphicPanel myPanel;

    public static void main(String[] args) {
        JFrame myFrame = new JFrame("Dice Roller");
        JFrame.setDefaultLookAndFeelDecorated(true);
        myPanel = new GraphicPanel();
        myPanel.setBounds(0, 0, 500, 200);
        myFrame.add(myPanel);
        JPanel lastPanel = new JPanel();
        myFrame.add(lastPanel);
        widget = new WidgetPanel();
        widget.setBounds(0, 250, 500, 300);
        myFrame.add(widget);
        widget.rollButton.addActionListener((ActionEvent newRoll) -> {
            new MCobbM10A1().myNewRollButtonPressed();
        });
        myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        myFrame.pack();
        myFrame.setVisible(true);
        myFrame.setBounds(0, 0, 500, 300);
    }
    private void myNewRollButtonPressed() {
        myPanel.newRoll();
    }
}

这是小部件面板：

public class WidgetPanel extends JPanel {
    JButton rollButton;
        WidgetPanel() {
            this.setBackground(Color.WHITE);
            this.setLayout(new BorderLayout());
            rollButton = new JButton();
            rollButton.setBounds(350, 200, 100, 25);
            rollButton.setText("Roll Dice");
            this.add(rollButton);
            JLabel fixBug = new JLabel();
            this.add(fixBug);
        } 
}

Answer 1

how to make the "Roll Dice" button the default allowing enter press.

您将默认按钮分配给框架的 JRootPane。

frame.getRootPane().setDefaultButton(…);

一种方法是：

@Override
public void addNotify()
{
    super.addNotify();

    JFrame frame = (JFrame)SwingUtilities.windowForComponent( rollButton );
    frame.getRootPane().setDefaultButton(rollButton);
}

将面板添加到框架时调用 addNotify() 方法。

Answer 2

与您的问题无关，但为什么要为每个卷创建一个新对象？

        widget.rollButton.addActionListener((ActionEvent newRoll) -> {
            new MCobbM10A1().myNewRollButtonPressed(); // <--- new MCobbM10A1 object
        });
        myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        myFrame.pack();
        myFrame.setVisible(true);
        myFrame.setBounds(0, 0, 500, 300);
    }
    private void myNewRollButtonPressed() {
        myPanel.newRoll();
    }

为什么不这样做呢？

    widget.rollButton.addActionListener((ae) ->
            myPanel.newRoll());

如何使滚动按钮默认允许按回车键？

How to make the roll button the default allowing enter press?

java

swing

awt