单选按钮不显示

Radio buttons don't show

我正在尝试在 java 中进行调查。我有 20 个问题和 5 个可能的选择。我正在考虑将 20 个标签和 100 个单选按钮按 5 个分组。

我设法使用 Net beans GUI 手动添加标签,但我想生成按钮,但它们没有显示。这是我的代码:

public class Prikaz extends javax.swing.JFrame {

    /**
     * Creates new form Prikaz
     */
    public Prikaz() {
        initComponents();
        javax.swing.JRadioButton [][] buttons = new javax.swing.JRadioButton [20][5];
        ButtonGroup [] bg = new ButtonGroup[20];


        for (int i = 0; i < 20; ++i) {
            bg[i]= new ButtonGroup();
            for (int j = 0; j < 5; ++j) {
                buttons[i][j] = new javax.swing.JRadioButton();
                if(j==0)buttons[i][j].setSelected(true);
                buttons[i][j].setLocation(1014+(j*24) , 44+(i*31));
                buttons[i][j].setToolTipText(((Integer)(j+1)).toString());
                buttons[i][j].setVisible(true);
                buttons[i][j].setEnabled(true);
                bg[i].add(buttons[i][j]);
            }
        }

    }

    // Variables declaration - do not modify                     
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel10;
    private javax.swing.JLabel jLabel11;
    private javax.swing.JLabel jLabel12;
    private javax.swing.JLabel jLabel13;
    private javax.swing.JLabel jLabel14;
    private javax.swing.JLabel jLabel15;
    private javax.swing.JLabel jLabel16;
    private javax.swing.JLabel jLabel17;
    private javax.swing.JLabel jLabel18;
    private javax.swing.JLabel jLabel19;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel20;
    private javax.swing.JLabel jLabel21;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel jLabel5;
    private javax.swing.JLabel jLabel6;
    private javax.swing.JLabel jLabel7;
    private javax.swing.JLabel jLabel8;
    private javax.swing.JLabel jLabel9;
    // End of variables declaration                   
}

除了 ButtonGroup 之外,您还需要将按钮添加到父组件。

例如,要将按钮添加到 jlabel1,请在创建按钮后添加:

jlabel1.add(buttons[i][j]);

编辑: 如果它不起作用,首先对每个 JLabel 执行 jLabel.setLayout(new FlowLayout()),然后添加新按钮。