如何跟蹤分數並檢查答案？

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，這樣我就可以使用動作監聽器了，但是當我輸入答案時，即使正確，我的答案還是錯誤的。 出現的第一個問題很好，但是之后，它說我所有的答案都是錯誤的，並且仍然無法跟蹤我的分數。

     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

為了使您的按鈕執行某些所需的操作，如您所說，您將需要使用ActionListener。 為此，您將需要定義一些實現ActionListener接口的類。 如果您願意，該類可以是您的PracticeMath類。 這樣做：

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

當您這樣做時，您的PracticeMath類將負責為ActionListener接口中包含的任何方法指定一個定義。 在這種情況下

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

然后，您需要將此ActionListener添加到您希望其監聽的任何按鈕上。 即

answerButton.addActionListener( this );

由於ActionListener是PracticeMath類，因此請使用“ this”作為參數。 現在，當您按下答案按鈕時，將調用您輸入到actionPerformed（...）方法中的任何代碼。 這樣您就可以在其中評估您的答案。

更新以反映以下評論：

這是actionPerformed方法的代碼。

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

當然，這不能解決您沒有檢查是否實際使用了正確的運算符這一事實，但這應該可以解決第一個答案以外的每個答案都被標記為不正確的問題。