JFrameに複数のパネルを追加するには？

Question

JFrameに8つの数学問題を追加したいと思います。すべてが 進行中の仕事ですが、ここで役に立つのは私のclass QuizQuestionです。

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; 
    } 

} 

はここに私のメインクラスです。これはもちろん問題がどこにあるかです。私は 8つの数学の問題を作成しています（今の問題はすべて同じです）。 8つの問題をすべて同じJFrameに取り込みたいと思っています。私は ループを使用すると、私はJFrameを作成してからループ をTryクラスまでループすると思ったが、うまくいきませんでした。だから私はどのようにすれば これを行うだろうか？

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

は、基本的には、あなたのTryJPanel秒のすべてが含まれていますBoxLayoutなどのレイアウトマネージャを持つJPanelを分離するためにwindowのコンテンツペインを設定します。ループ内の新しいJPanelに各Tryインスタンスを追加します。次のようなもの：

Answer 2

カードレイアウトを使用して、一度に1つのパネルを表示します。