注册系统程序中的错误代码。如何添加类似性别的选项：(男性还是女性)？(Java netbeans)

Question

此代码有一个错误，即：

private JLabel snL, fnL, mnL, gL, aL, adL, cnL, sbjL, aL, rL, tL, tfL;
private JTextField snTF, fnTF, mnTF, gTF, aTF, adTF, cnTF, sbjTF, aTF, rTF, tTF, tfTF;

这就是整个计划。

import javax.swing.*;
import java.awt.*;

public class EnrollmentSystem2 extends JFrame
{        
        private static final int WIDTH = 500;
        private static final int HEIGHT = 400;

        private JLabel snL, fnL, mnL, gL, aL, adL, cnL, sbjL, aL, rL, tL, tfL;
        private JTextField snTF, fnTF, mnTF, gTF, aTF, adTF, cnTF, sbjTF, aTF, rTF, tTF, tfTF;

public EnrollmentSystem2()
{
    setTitle ("UPHSD Enrollment");        
    snL = new JLabel ("  Surname:", SwingConstants.LEFT);
    fnL = new JLabel ("  First Name:", SwingConstants.LEFT);
    mnL = new JLabel ("  Middle Name:", SwingConstants.LEFT);
    gL = new JLabel ("  Gender:", SwingConstants.LEFT);
    aL = new JLabel ("  Age:", SwingConstants.LEFT);
    adL = new JLabel ("  Adress:", SwingConstants.LEFT);
    cnL = new JLabel ("  Contact No.:", SwingConstants.LEFT);
    sbjL = new JLabel ("  Suject:", SwingConstants.LEFT);
    aL = new JLabel ("  Assesstment:", SwingConstants.LEFT);
    rL = new JLabel ("  Room:", SwingConstants.LEFT);
    tL = new JLabel ("  Time:", SwingConstants.LEFT);
    tfL = new JLabel ("  Tuition fee:", SwingConstants.LEFT);

    snTF = new JTextField (10);
    fnTF = new JTextField (10);
    mnTF = new JTextField (10);
    gTF = new JTextField (10);
    aTF = new JTextField (10);
    adTF = new JTextField (10);
    cnTF = new JTextField (10);
    sbjTF = new JTextField (10);
    aTF = new JTextField (10);
    rTF = new JTextField (10);
    tTF = new JTextField (10);
    tfTF = new JTextField (10);

    Container pane = getContentPane();
    pane.setLayout (new GridLayout(9,2));

    pane.add(snL);
    pane.add(snTF);
    pane.add(fnL);
    pane.add(fnTF);
    pane.add(mnL);
    pane.add(mnTF);
    pane.add(gL);
    pane.add(gTF);
    pane.add(aL);
    pane.add(aTF);
    pane.add(adL);
    pane.add(adTF);
    pane.add(cnL);
    pane.add(cnTF);   
    pane.add(sbjL);
    pane.add(sbjTF);
    pane.add(aL);
    pane.add(aTF);
    pane.add(rL);
    pane.add(rTF);
    pane.add(tL);
    pane.add(tTF);
    pane.add(tfL);
    pane.add(tfTF);

    setSize(WIDTH, HEIGHT);
    setVisible (true);
    setDefaultCloseOperation (EXIT_ON_CLOSE);
}

public static void main (String[]args)
{
    EnrollmentSystem2 Object = new EnrollmentSystem2();
}


}

Answer 1

您已经声明了两个名称为aL的标签。每个变量都必须有唯一的名称。

编辑:与aTF相同

顺便说一句，您的导入语句应该是：

import javax.swing.*; 
import java.awt.*;