Question

我想在JFrame中添加8个数学问题。一切都是工作进度，但如果它有用，我的class QuizQuestion。

public class QuizQuestion {
    private String question;
    private int answer;

    public QuizQuestion(){
        question = "5 + 3";
        answer = 5 + 3;
    }
    public String getQuestion() {
        return question;
    }

    public int getAnswer() {
        return answer;
    }

}

这是我的主要课程。这当然是问题所在。我＆＃39;米创造8个数学问题（现在所有相同的问题），和我想将所有8个问题都放到同一个JFrame上。我想使用循环可以工作，因为我创建JFrame然后循环通过Try课程，但这不起作用。那我该怎么办？此？

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;

import javax.swing.JPanel;
import javax.swing.JTextField;

public class Try extends JPanel {
    private JLabel display;          // this is used to display output to the user 
    private JTextField answerInput;  // the box where the user enters his answer
    private JButton button;          // a "Submit" button that the user clicks to submit answer
    private QuizQuestion question;   // the current math question that the user has to answer
    private long startTime = 0;
    private long endTime;
    private int correctFirstTry;     // number of questions answered correctly by the user on the first try
    private int correctSecondTry;    // number of questions answered correctly by the user on the second try
    private int incorrect;           // number of questions not answered correctly after two tries
    private final static int STARTING = 0;   // represents the "state" before any questions have been asked
    private final static int FIRST_TRY = 1;  // the state while waiting for the first answer to a question
    private final static int SECOND_TRY = 2; // the state while waiting for the second answer to a question

    private int state = STARTING;

    public Try(){
        setLayout(new BorderLayout());
        display = new JLabel("Question");
        display.setPreferredSize(new Dimension(500, 50));
        display.setHorizontalAlignment(JLabel.CENTER);
        display.setVerticalAlignment(JLabel.CENTER);
        add(display,BorderLayout.CENTER);
        JPanel bottom = new JPanel();
        bottom.add(new JLabel("Enter Answer Here: "));
        answerInput = new JTextField(4);
        answerInput.setEnabled(false);
        bottom.add(answerInput);
        button = new JButton("Show Question");
        button.addActionListener( new ActionListener() { 
            public void actionPerformed(ActionEvent evt) {
                buttonPressed();
            }
        });
        bottom.add(button);
        add(bottom, BorderLayout.SOUTH);
    }
    private void buttonPressed() {

        if (state == STARTING) {    // Create and display the first question; change state to FIRST_TRY.
            question = new QuizQuestion();
            this.startTime = System.currentTimeMillis()/1000;
            display.setText("First Question" + "\t" + question.getQuestion());
            answerInput.setEnabled(true);
            answerInput.requestFocus();
            button.setText("Submit");
            state = FIRST_TRY;
            return;
        }

        String userInput = answerInput.getText().trim();  // Get user's input from the input box.

        if (userInput.length() == 0) { // Nothing was entered in the box; give an appropriate error message.
            errorMessage("Enter your answer in the input box,\nand then click the Submit button.");
            return;
        }

        int userAnswer;  // user's answer as an integer value
        try {
            userAnswer = Integer.parseInt(userInput);  // convert input string to integer
        }
        catch (NumberFormatException e) {  // Input was not valid; give an appropriate error message.
            errorMessage("\"" + userInput + "\" is not a legal integer.\nPlease enter your answer as an integer.");
            return;
        }

        // At this point, we have the user's answer stored in the int variable userAnswer, and the
        // state is FIRST_TRY or SECOND_TRY.  Check the answer and respond accordingly.

        String response;  // This will be the program's feedback to the user about the answer.

        if (state == FIRST_TRY) {
            if (userAnswer == question.getAnswer()) {
                endTime = System.currentTimeMillis()/1000 - startTime;
                response = "Good Job!  That's correct. "
                        + "Time it took to answer Question: " + endTime + "sec(s)";
                correctFirstTry++;
            }
            else {   // Keep the same question, but change state to SECOND_TRY.
                response = "Sorry, that's not correct.  Try again:";
                state = SECOND_TRY;
            }
        }
        else {  // state is SECOND_TRY
            if (userAnswer == question.getAnswer()) {
                endTime = System.currentTimeMillis()/1000 - startTime;
                response = "Correct on the second try!"
                        + "Time it took to answer Question: " + endTime + "sec(s)";
                correctSecondTry++;
            }
            else {
                endTime = System.currentTimeMillis()/1000 - startTime;
                response = "Sorry, the correct answer is " + question.getAnswer()
                + "Time it took to answer Question: " + endTime + "sec(s)";
                incorrect++;
            }
        }

        display.setText(response);
        answerInput.selectAll();      // Highlights the contents of the input box.
        answerInput.requestFocus();   // Moves input focus to input box, so user doesn't have to click it.

    } // end buttonPressed()
    private void errorMessage(String message) {
        JOptionPane.showMessageDialog(this, message, "Error in Input", JOptionPane.ERROR_MESSAGE);
    }
    public static void main(String[] args) {
        JFrame window = new JFrame("Problems");
        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        for(int i = 0; i < 8; i++){
            window.setContentPane(new Try());
            window.pack();
            window.setVisible(true);
        }
    }
}

Answer 1

基本上，您希望将window的内容窗格设置为单独JPanel，其中包含BoxLayout等布局管理器，其中包含您的所有Try {{1} }}秒。然后将每个JPanel实例添加到循环中的新Try。类似的东西：

JPanel

Answer 2

使用卡片布局并一次显示一个面板。

如何将多个面板添加到JFrame？

2 个答案: