import java.awt.BorderLayout; import java.awt.Color; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import java.awt.event.KeyListener; import java.util.ArrayList; import java.util.List; import java.util.Random;  import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextField;  /**  * 2017-01-09  * @author Koow  *  */ public class sa extends JFrame implements ActionListener, KeyListener {  private JLabel private JButton submit = null;  private JPanel center = null;  // items用來跳轉  private int item1 = 0;  private int item2 = 1;  private int item3 = 2;  private int item4 = 3;  private JLabel[] FormulaLabels; // 用來存放表達式的各個項  private List<String> allResult; // 用來存放隨機出來的結果  private JTextField[] userResults; // 用來讓用戶輸入結果  private JLabel[] judge; // 用來顯示圖標，以顯示用戶輸入的結果是否正確  private List<String> inputResults = null; // 可以不要  private JTextField scoreField = null;  private int textCount = 1; // 用來記錄當前焦點的位置    public static void main(String[] args){   sa s=new sa();     }   public sa() {   // TODO Auto-generated constructor stub   inputResults = new ArrayList<String>();   // 實例化  submit = new JButton("提交");   submit.addActionListener(this);   GridLayout layout = new GridLayout(21, 6);   center = new JPanel(layout);   // 調用方法實例化方法   initLables();   initUserRestult();   initJudge();   // 將各項填入到center面板(GridLayout)   int count = 1;   int formulaCount = 0;   int userResultsCount = 0;   int judgeCount = 0;   while (count <= 120) {    // 判斷count%6,確定要填哪個組件    if (count % 6 == 1 || count % 6 == 2 || count % 6 == 3 || count % 6 == 4) {     center.add(FormulaLabels[formulaCount]);     formulaCount++;    } else if (count % 6 == 5) {     center.add(userResults[userResultsCount]);     userResultsCount++;    } else if (count % 6 == 0) {     center.add(judge[judgeCount]);     judgeCount++;    }    count++;   }   center.add(new JLabel());   center.add(new JLabel());   center.add(new JLabel("總分："));   scoreField = new JTextField();   scoreField.setEditable(false);   center.add(scoreField);   center.add(new JLabel());   center.add(new JLabel());   this.add(center, BorderLayout.CENTER);   // 添加組件   this.add(submit, BorderLayout.SOUTH);   this.add(title, BorderLayout.NORTH);   // 顯示   this.setLocation(400, 10);   this.setVisible(true);   this.setSize(500, 700);   this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   this.setTitle("簡單測試系統");   try {    Thread.sleep(500);   } catch (InterruptedException e) {    // TODO Auto-generated catch block    e.printStackTrace();   }   userResults[0].requestFocus();  }   /**   * 這個方法用來初始化算式各項的數組   */  private void initLables() {   int sum;   int firstNumber;   int secondNumber;   allResult = new ArrayList<String>();   // 建立算式標簽   this.FormulaLabels = new JLabel[80];   // 將數組中的每一個標簽都實例化   for (int i = 0; i < 80; i++) {    FormulaLabels[i] = new JLabel();   }   // 將表達式各項賦值內容，并將隨機數的和算出結果存入Arraylist中,以便后期核對結果使用   while (item4 < 80) {    firstNumber = new Random().nextInt(99) + 1;    FormulaLabels[item1].setText(String.valueOf(firstNumber));    FormulaLabels[item2].setText("+");    secondNumber = new Random().nextInt(99) + 1;    FormulaLabels[item3].setText(String.valueOf(secondNumber));    FormulaLabels[item4].setText("=");    sum = firstNumber + secondNumber;    allResult.add(String.valueOf(sum));    item1 += 4;    item2 += 4;    item3 += 4;    item4 += 4;   }   // for(int i=0;i<80;i++){   // System.out.println(FormulaLabels[i].getText());   // }  }   /**   * 這個方法用來實例化userResults數組，并實例化里面的每一個JTextField   */  private void initUserRestult() {   userResults = new JTextField[20];   for (int i = 0; i < 20; i++) {    userResults[i] = new JTextField();    userResults[i].setSize(20, 20);    // 后加的監聽    userResults[i].addKeyListener(this);   }  }   /**   * 這個方法用來實例化judge數組，并將里面的每一個Label實例化   */  private void initJudge() {   judge = new JLabel[20];   for (int i = 0; i < 20; i++) {    judge[i] = new JLabel("好好算呦");   }  }   // 實現監聽方法，當用戶點擊提交后要做的事情  @Override  public void actionPerformed(ActionEvent arg0) {   // TODO Auto-generated method stub   int score = 0;   for (int i = 0; i < 20; i++) {    // 將用戶輸入的結果全部獲取，存入一個ArrayList中,可以不要    inputResults.add(userResults[i].getText().toString().trim());    System.out.println(userResults[i].getText().toString());    // 取出來用戶輸入的答案和之前算好的結果去比較，不對就把后面的標簽設置為回答錯誤，    // 如果正確就設置為回答正確    String result = userResults[i].getText().toString().trim();    if (result.equals(allResult.get(i))) {     judge[i].setText("回答正確");     judge[i].setForeground(Color.RED);     score++;    } else {     judge[i].setText("回答錯誤");     judge[i].setForeground(Color.GREEN);    }   }   scoreField.setText(String.valueOf(score));  }   @Override  public void keyPressed(KeyEvent e) {   // TODO Auto-generated method stub   if (e.getKeyCode() == KeyEvent.VK_ENTER) {    userResults[textCount].requestFocus();    if (textCount < 19) {     textCount++;    }   }  }   @Override  public void keyTyped(KeyEvent e) {   // TODO Auto-generated method stub   }   @Override  public void keyReleased(KeyEvent e) {   // TODO Auto-generated method stub   } }