我正在尝试制作它，以便根据是否按下单选按钮来使用Java图形并创建一个带有预设图形的小程序。尽管我尝试使用if语句，但是它告诉我不能将JRadioButton转换为boolean，但是我觉得这样做不是正确的方法。我拉头发是因为我不知道该怎么做。
帮助/指导将不胜感激：D！谢谢 ！
我的代码如下所示：
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class RadioButton extends JPanel {
static JFrame frame;
JLabel pic;
RadioListener myListener = null;
public RadioButton() {
// Create the radio buttons and assign Keyboard shortcuts using Mnemonics
JRadioButton displacement = new JRadioButton("Displacement");
displacement.setMnemonic(KeyEvent.VK_N);
displacement.setSelected(true);
//Displacement Button, set to automatically be clicked
JRadioButton accel = new JRadioButton("Acceleration");
accel.setMnemonic(KeyEvent.VK_A);
accel.setActionCommand("acceleration");
//Acceleration Button
JRadioButton time = new JRadioButton("Change in time");
time.setMnemonic(KeyEvent.VK_S);
time.setActionCommand("deltaT");
//The change in time button
// Creates the group of buttons
ButtonGroup group = new ButtonGroup();
group.add(displacement);
group.add(accel);
group.add(time);
myListener = new RadioListener();
displacement.addActionListener(myListener);
accel.addActionListener(myListener);
time.addActionListener(myListener);
// Set up the picture label
pic = new JLabel(new ImageIcon(""+"numbers" + ".jpg")); //Set the Default Image
pic.setPreferredSize(new Dimension(177, 122));
// Puts the radio buttons down
JPanel panel = new JPanel();
panel.setLayout(new GridLayout(0, 1));
panel.add(displacement);
panel.add(accel);
panel.add(time);
setLayout(new BorderLayout());
add(panel, BorderLayout.WEST);
add(pic, BorderLayout.CENTER);
setBorder(BorderFactory.createEmptyBorder(40,40,40,40));
}
if ( displacement.setSelected(true))
{
}
//Listening to the buttons
class RadioListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
pic.setIcon(new ImageIcon(""+e.getActionCommand()
+ ".jpg"));
}
}
public static void main(String s[]) {
frame = new JFrame("∆x = Vavg * time");
frame.addWindowListener(new WindowAdapter() {
最佳答案
您正在将true设置为isSelected()。但是，根据您的描述，您要检查是否已选择它。
采用：
if ( displacement.isSelected())
{
}
代替：
if ( displacement.setSelected(true))
{
}