Question

我有一个创建行的循环，其中每一行都有另一个循环来创建6个JRadioButtons。

每行只能选择一个JRadioButton（应该是这样），但是我发现很难使用Action Listeners检查是否从每一行中选择了正确的JRadioButton，然后将空的JLabel更改为显示“正确”，但我认为一旦我完成第一部分就会很简单。

这是我正在使用的相关代码：

    //loop for making flow layout for each line of random letters
    //counter for having number of the row next to each row in order of selection
    int counter = x;
    for(int i = 0; i < x; i++)
    {
        //new jpanel created for every row needed for the word
        JPanel jpLine = new JPanel(new FlowLayout());

        //new jlabel made with counter number for each row
        JLabel count = new JLabel(Integer.toString(counter));
        jpLine.add(count);
        counter--;
        //random number from 0-5 generated for each row
        Random number = new Random();
        int low = 0;
        int high = 5;
        int ranNumber = number.nextInt((high - low) + low);

        //buttongroup outside loop so only one button can be pressed for each row
        ButtonGroup bg = new ButtonGroup();

        //get selected button's index in any group with bg.getSelection().getActionCommand()
        final int row = i;
        final ButtonGroup btnG = bg;
        ActionListener listener = new ActionListener() 
        {
            public void actionPerformed(ActionEvent e) 
            {



                System.out.println("row " + row);
                System.out.println("btn " + btnG.getSelection().getActionCommand());



            }
        };

        //loop for making the number of letters in each row - always going to be 6 letters to choose from in each row
        for(int j = 0; j < 5; j++)
        {
            //if the random number generated for each row equals the loop
            //then new radiobutton will be created for the ith letter of the reversed
            //answer, starting from charAt 0 and going to the last character
            if(ranNumber == j)
            {
                JRadioButton answerLetter = new JRadioButton("<html><font color = 'white'>" + answerForGrid.charAt(i) + "</font></html>");

                bg.add(answerLetter);
                answerLetter.setBackground(Color.decode("#566771"));
                answerLetter.setOpaque(true);
                jpLine.add(answerLetter);

                //use setActionCommand("" + j) on each button to associate each button with its index
                answerLetter.setActionCommand("" + j);
                answerLetter.addActionListener(listener);
            }

            //ranLetter is generated randomly from the alphabet string, so random letters are
            //created for each jradiobutton
            final String alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
            final int N = alphabet.length();

            Random letter = new Random();
            char ranLetter;

            while(true) 
            {
                ranLetter = alphabet.charAt(letter.nextInt(N));
                break;
            }

            JRadioButton k = new JRadioButton("<html><font color = 'white'>" + ranLetter + "</font></html>");

            bg.add(k);
            k.setBackground(Color.decode("#566771"));
            k.setOpaque(true);
            jpLine.add(k);
        }
        //add each row of letters (jpLine) to this loops jpanel
        jpCenterCenter.add(jpLine);
    }

另外，我想要检查的正确的JRadioButtons是在if（ranNumber == j）部分创建的。

很抱歉，如果我拖延了，但我发现这很难解释，所以希望有人能够提供帮助！

Answer 1

您可以在每个按钮上使用setActionCommand("" + j)将每个按钮与其索引相关联，然后在bg.getSelection().getActionCommand()的任何组中获取所选按钮的索引。然后，您可以将单个ActionListener分配给一个组中的所有按钮，并确保操作侦听器知道它附加到哪一行。

// in your "i" loop
final int row = i; // must be final to be used inside the anonymous class
final ButtonGroup btnG = bg;
final String answerAction = "" + ranNumber; // hard to tell if this is what you mean
ActionListener listener = new ActionListener() {
  public void actionPerformed(ActionEvent e) {
    System.out.println("row " + row);
    String selectedAction = btnG.getSelection().getActionCommand();
    System.out.println("btn " + selection);
    boolean isCorrectForThisRow = (answerAction == selectedAction);
    System.out.println("is correct: " + isCorrectForThisRow);
  }
};
// in your "j" loop, with either the answerLetter or k buttons
// as required
k.setActionCommand("" + j);
k.addActionListener(listener);

就目前而言，您的样本中有很多内容并不合理，因此很难提出更多建议（例如 - 一个while(true)循环中断它的第一次迭代）。但是setActionCommand意图以这种方式使用（oracle tutorial here）以找出在按钮组中选中的按钮。

如果已在循环中创建了jRadioButtons，请检查它们已被选中

1 个答案: