Question

我想在这个面板初始化时选择随机单选按钮，但我不确定如何/如果我能做到这一点。

有没有办法从组中获取随机按钮并选择它？

import javax.swing.*;

public class RandomPanel extends JPanel
{
    private ButtonGroup buttonGroup;
    private String[] buttonText =
            {
                    "Red",
                    "Mashed Potatoes",
                    "Metal",
                    "Running",
                    "Butts",
                    "Turquoise"
            };

    public RandomPanel()
    {
        setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
        setBorder(BorderFactory.createTitledBorder("Random Selections"));

        buttonGroup = new ButtonGroup();
        for (String text : buttonText)
        {
            JRadioButton option = new JRadioButton(text);
            add(option);
            button.add(option);
        }
    }

}

Answer 1

你可以做的是保留你创建的所有单选按钮的列表/数组，然后使用按钮组的setSelected（）方法设置所选择的按钮，如下所示

buttonGroup.setSelected(buttonsArray[randomButtonNum].getModel(), true);

Answer 2

尝试使用Random类。

    // Library location
    import java.util.Random;

    //Inside some method
    Random r = new Random();
    randomIndex = r.nextInt(buttonText.length());
    text = buttonText[randomIndex];

这需要安排适合您的实施，所显示的是“操作方法”和＃39;的使用。

注意：nextInt(args)的参数是独占的。即将返回 0 <= x < args

Answer 3

我相信你正在寻找类似下面的解决方案。

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;

import javax.swing.*;

public class RandomPanel extends JPanel
{
    private ButtonGroup buttonGroup;
    private String[] buttonText =
            {
                    "Red",
                    "Mashed Potatoes",
                    "Metal",
                    "Running",
                    "Butts",
                    "Turquoise"
            };

    private JRadioButton[] radioButton;

    Random r = new Random();

    public RandomPanel()
    {
        setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
        setBorder(BorderFactory.createTitledBorder("Random Selections"));

        buttonGroup = new ButtonGroup();

        radioButton = new JRadioButton[buttonText.length];

        for(int rb=0; rb<buttonText.length; rb++)
        {
            radioButton[rb] = new JRadioButton(buttonText[rb]);
            add(radioButton[rb]);
            buttonGroup.add(radioButton[rb]);
        }

        JButton b = new JButton("Random");
        b.addActionListener(new ActionListener()
        {
            @Override
            public void actionPerformed(ActionEvent e)
            {
                selectRandomButton();
            }
        });

        add(b);
    }

    public void selectRandomButton()
    {
        radioButton[r.nextInt(radioButton.length)].setSelected(true);
    }

    public static void main(String[] args)
    {
        JFrame f = new JFrame("Test Random Button");
        f.setSize(300, 300);
        f.setLocationRelativeTo(null);;
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        f.add(new RandomPanel());

        f.setVisible(true);;
    }
}

Answer 4

我创建了一个小方法，允许我设置任何单选按钮组。如果您不想使用if用于任何单选按钮，则非常方便。

public void setButtonGroup(int rdValue, Enumeration elements ){
    while (elements.hasMoreElements()){
        AbstractButton button = (AbstractButton)elements.nextElement();
        if(Integer.parseInt(button.getActionCommand())==rdValue){
            button.setSelected(true);
        }
    }
}

然后

setButtonGroup(randomIndex, yourButtonGroup.getElements());

如何随机选择JRadioButtons的ButtonGroup中的按钮？

4 个答案: