如何跟踪分数并检查答案？

Question

I trying to make a math quiz game that generates random question and keep track of of what question are wrong and write.

I trying to figure out how to make my program respond if the answer written in the text field is correct or incorrect when I click the JButton `answerbutton`. I'm very new to using `ActionListener`.

好的，这样我就可以使用动作监听器了，但是当我输入答案时，即使正确，我的答案还是错误的。 出现的第一个问题很好，但是之后，它说我所有的答案都是错误的，并且仍然无法跟踪我的分数。

     import java.util.Scanner;
        import javax.swing.*;
        import javax.swing.border.TitledBorder;

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

        public class PracticeMath extends JFrame {
            Scanner k = new Scanner(System.in);
            Random generator = new Random();
            protected JButton excerciseButton = new JButton( "New Excerices" ); // start new quiz session
            protected JButton answerButton = new JButton( "Answer" ); // set new question, check if the answer correct or wrong
            protected JLabel titlelabel = new JLabel( "How much is: " ); 
            protected int correctcounter = 0; // keep track of correct answer
            protected int wrongcounter = 0; // keep track of wrong answer
            protected int one = generator.nextInt(10);//generate ranodm first number of question
            protected int two = generator.nextInt(10); // generate random second number of question
            protected int i = generator.nextInt(4); // generate random operator
            protected char[] ops = { '+', '-', '/', '*' }; // the math operator
            protected JLabel correctlabel = new JLabel(" Number of Correct Answer: ");
            protected JLabel wronglabel = new JLabel( " Number of  Wrong answers:  " );
            protected JLabel firstnum = new JLabel("" + one); // display first number
            protected JLabel secondnum = new JLabel("" + two); //  display second number
            protected JLabel randomOP = new JLabel("" + ops[i]); display operator
            protected JLabel equalOP = new JLabel("=");
            protected JTextField answerText = new JTextField(); //text area for writing you answer
            protected JLabel questionmark = new JLabel("?");
            protected JLabel correct = new JLabel(""+ correctcounter); // display correct answer
            protected JLabel wrong = new JLabel(""+ wrongcounter); // display wrong answer
            protected JLabel commentlabel = new JLabel(""); // set a comment for how good you doing. optionial




            public PracticeMath(){

                answerText.setColumns(5);

                JPanel Panel1 = new JPanel();// add a panel
                FlowLayout flowLayout = (FlowLayout) Panel1.getLayout();// layout for panel
                getContentPane().setLayout( new FlowLayout( FlowLayout.LEFT, 5, 5)); // set layout
                getContentPane().add(Panel1); // set panel
                titlelabel.setForeground(Color.ORANGE); 
                titlelabel.setFont(new Font("Tahoma", Font.PLAIN, 25));

                Panel1.add(titlelabel);
                firstnum.setFont(new Font("Tahoma", Font.PLAIN, 20));
                Panel1.add(firstnum);

                randomOP.setFont(new Font("Tahoma", Font.PLAIN, 25));
                Panel1.add(randomOP);

                secondnum.setFont(new Font("Tahoma", Font.PLAIN, 20));

                Panel1.add(secondnum);

                equalOP.setFont(new Font("Tahoma", Font.PLAIN, 20));
                Panel1.add(equalOP);

                Panel1.add(answerText);

                questionmark.setFont(new Font("Tahoma", Font.PLAIN, 20));
                Panel1.add(questionmark);

                Panel1.add(commentlabel);



                JPanel Panel3 = new JPanel();
                FlowLayout flowLayout3 = (FlowLayout) Panel3.getLayout();
                flowLayout3.setHgap(15);
                getContentPane().setLayout( new FlowLayout( FlowLayout.LEFT, 5, 5));
                getContentPane().add(Panel3);
                Panel3.add(excerciseButton);
                Panel3.add(answerButton);



                    JPanel panel2 = new JPanel();
                panel2.setBorder(new TitledBorder("Statistic"));
                getContentPane().add(panel2);
                panel2.setLayout(new GridLayout(0, 2, 0, 0));
                panel2.add(correctlabel);
                panel2.add(wronglabel);
                correct.setForeground(Color.GREEN);
                correct.setFont(new Font("Tahoma", Font.PLAIN, 25));
                panel2.add(correct);

                wrong.setForeground(Color.RED);
                wrong.setFont(new Font("Tahoma", Font.PLAIN, 25));
                panel2.add(wrong);




            answerButton.addActionListener( this );

            }






           public static void main(String[] args) {

                PracticeMath frame = new PracticeMath();
                frame.pack();
                frame.setLocationRelativeTo(null);  
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setSize(400,400);
                frame.setTitle( "Math Practice");
                frame.setVisible(true);





            }

         public void actionPerformed( ActionEvent ae )
   {
       String answer = answerText.getText();
       int answerint = Integer.parseInt(answer);
       if(one + two == answerint){
            correctcounter++;
            System.out.println("correct");
            firstnum.setText("" + generator.nextInt(11));
               randomOP.setText("" + ops[generator.nextInt(4)]);
               secondnum.setText("" + generator.nextInt(11));


        }
       else if(one-two == answerint){
            correctcounter++;
            System.out.println("correct");
            firstnum.setText("" + generator.nextInt(11));
               randomOP.setText("" + ops[generator.nextInt(4)]);
               secondnum.setText("" + generator.nextInt(11));
        }
        else if(one * two ==answerint){
            correctcounter++;
            System.out.println("correct");
            firstnum.setText("" + generator.nextInt(11));
               randomOP.setText("" + ops[generator.nextInt(4)]);
               secondnum.setText("" + generator.nextInt(11));
        }else if(one/two == answerint){
            correctcounter++;
            System.out.println("correct");
            firstnum.setText("" + generator.nextInt(11));
               randomOP.setText("" + ops[generator.nextInt(4)]);
               secondnum.setText("" + generator.nextInt(11));
        }
        else{
            wrongcounter++;
            System.out.println("wrong");
            firstnum.setText("" + generator.nextInt(11));
               randomOP.setText("" + ops[generator.nextInt(4)]);
               secondnum.setText("" + generator.nextInt(11));
        }
   }
}

Answer 1

为了使您的按钮执行某些所需的操作，如您所说，您将需要使用ActionListener。 为此，您将需要定义一些实现ActionListener接口的类。 如果您愿意，该类可以是您的PracticeMath类。 这样做：

public class PracticeMath extends JFrame implements ActionListener
{...}

当您这样做时，您的PracticeMath类将负责为ActionListener接口中包含的任何方法指定一个定义。 在这种情况下

public void actionPerformed( ActionEvent ae )
{
    // put something intelligent here
}

然后，您需要将此ActionListener添加到您希望其监听的任何按钮上。 即

answerButton.addActionListener( this );

由于ActionListener是PracticeMath类，因此请使用“ this”作为参数。 现在，当您按下答案按钮时，将调用您输入到actionPerformed（...）方法中的任何代码。 这样您就可以在其中评估您的答案。

更新以反映以下评论：

这是actionPerformed方法的代码。

public void actionPerformed( ActionEvent ae )
{
    String answer = answerText.getText();
   int answerint = Integer.parseInt(answer);
   if(one + two == answerint){
        correctcounter++;
        System.out.println("correct");
        one = generator.nextInt(11);
        two = generator.nextInt(11);
        // I don't know if you actually store the operator anywhere
        operator = ops[generator.nextInt(4)];
        firstnum.setText("" + one);
           randomOP.setText("" + operator);
           secondnum.setText("" + two);
    }
   else if(one-two == answerint){
       // ... and do the same for the other cases too

当然，这不能解决您没有检查是否实际使用了正确的运算符这一事实，但这应该可以解决第一个答案以外的每个答案都被标记为不正确的问题。