Android應用程序測驗中的隨機和循環問題

Question

我感到困惑。我正在開發一個測驗。我一直在試圖隨機化問題。我試圖在Cursor和Rawquery中隨機化，但無濟於事。

同時，我希望應用程序在最後一個問題後循環回答問題。

這裏是我的Question.java（這是我的活動）

public class Question extends Activity { 


    public static final String TAG = Question.class.getSimpleName(); 
    private TextView mTimer; 
    private Button mTimerButton; 
    private CountDownTimer mCountDownTimer; 
    private TextView mQuestionTextView; 
    private Button mNextQuestion; 
    private Button mHowtoplay2; 
    List<QuestionFaci> quesList; 
    int qid = 0; 

    QuestionFaci currentQ; 

    @Override 
    protected void onSaveInstanceState(Bundle outState){ 
     super.onSaveInstanceState(outState); 


    } 

    @Override 
    protected void onRestoreInstanceState(Bundle savedInstanceState){ 
     super.onRestoreInstanceState(savedInstanceState); 


    } 


    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_question); 

     mHowtoplay2 = (Button) findViewById(R.id.howtoplaybutton); 
     mHowtoplay2.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       startHowtoplay(); 
      } 
     }); 


     QuizHelper db = new QuizHelper(this); 
     quesList = db.getAllQuestions(); 
     currentQ = quesList.get(qid); 

     mQuestionTextView = (TextView) findViewById(R.id.questionView ); 
     mNextQuestion = (Button)findViewById(R.id.nextbutton); 

     View.OnClickListener listener = new View.OnClickListener(){ 

      @Override 
      public void onClick(View v) { 
       currentQ=quesList.get(qid); 
       setQuestionView(); 
      } 
     }; 

     mNextQuestion.setOnClickListener(listener); 
     Log.d(TAG, "We're logging from the onCreate() method"); 


    private void startHowtoplay(){ 
     Intent intent = new Intent(this, Howtoplay.class); 
     startActivity(intent); 
    } 
    private void setQuestionView(){ 
     mQuestionTextView.setText(currentQ.getQUESTION()); 
     qid++; 
    } 
} 

這裏是我的QuizHelper

public class QuizHelper extends SQLiteOpenHelper { 

    private static final int DATABASE_VERSION = 1; 
    private static final String DATABASE_NAME = "creativequestion"; 
    private static final String TABLE_QUEST = "quest"; 
    private static final String KEY_ID = "qid"; 
    private static final String KEY_QUEST = "question"; 

    private SQLiteDatabase dbase; 

    public QuizHelper(Context context) { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 
     dbase = db; 
     String sql = "CREATE TABLE IF NOT EXISTS " + TABLE_QUEST + " (" + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_QUEST + " TEXT)"; 
     db.execSQL(sql); 
     addQuestion(); 
    } 

    private void addQuestion() { 

     QuestionFaci q1 = new QuestionFaci("OTHER USES: Name other uses of a Hammer. \n\n Example: Stir a soup."); 
     this.addQuestion(q1); 
     QuestionFaci q2 = new QuestionFaci("RHYMES: Words that rhymes with Rice. \n\n Example: Ice"); 
     this.addQuestion(q2); 
     QuestionFaci q3 = new QuestionFaci("WITH: I can cook eggs with... \n\n Example: A Piece of Plywood"); 
     this.addQuestion(q3); 
     QuestionFaci q4 = new QuestionFaci("WITHOUT: I can wash my clothes without... \n\n Example: My Aunt"); 
     this.addQuestion(q4); 
     QuestionFaci q5 = new QuestionFaci("I WILL: If I was Bill Gates, I will... \n\n Example: Buy a spaceship"); 
     this.addQuestion(q5); 
     QuestionFaci q6 = new QuestionFaci("CREATE A MOVIE TITLE: A NIGHT \n\n Example: To Remember"); 
     this.addQuestion(q6); 
     QuestionFaci q7 = new QuestionFaci("OTHER NAMES: Other names of a cow \n\n Example: Milk giver"); 
     this.addQuestion(q7); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldV, int newV) { 
     db.execSQL("DROP TABLE IF EXISTS" + TABLE_QUEST); 
     onCreate(db); 

    } 
    private void addQuestion(QuestionFaci quest) { 
     ContentValues values = new ContentValues(); 
     values.put(KEY_QUEST, quest.getQUESTION()); 
     dbase.insert(TABLE_QUEST, null, values); 
    } 


    public List<QuestionFaci> getAllQuestions(){ 
     List<QuestionFaci> quesList = new ArrayList<QuestionFaci>(); 
     String selectQuery = "SELECT * FROM " + TABLE_QUEST; 
     dbase = this.getReadableDatabase(); 
     Cursor cursor = dbase.rawQuery(selectQuery, null); 
     if (cursor.moveToFirst()){ 
      do{ 
       QuestionFaci quest = new QuestionFaci(); 
       quest.setID(cursor.getInt(0)); 
       quest.setQUESTION(cursor.getString(1)); 

       quesList.add(quest); 
       } while (cursor.moveToNext()); 
     } 

     return quesList; 

    } 
} 

這是我QuestionFaci在我的getter和setter

public class QuestionFaci extends Activity { 

    private int ID; 
    private String QUESTION; 

    public QuestionFaci(){ 

     ID=0; 
     QUESTION= ""; 

    } 

    public QuestionFaci (String qUESTION){ 
     QUESTION = qUESTION; 
    } 

    public int getID(){ 
     return ID; 
    } 

    public String getQUESTION(){ 
     return QUESTION; 
    } 

    public void setID(int id){ 
     ID = id; 
    } 

    public void setQUESTION(String qUESTION){ 
     QUESTION = qUESTION; 
    } 
} 

Answer 1

替換爲：

private void setQuestionView(){ 
    Random r = new Random(); 
    int Low = 0; 
    int High = quesList.size(); 
    int Result = r.nextInt(High-Low) + Low; // 0 - questions size() -> select random 
    qid = Result; 
    mQuestionTextView.setText(currentQ.getQUESTION()); // set Question 

} 

如果您希望以前的問題不再出現，您必須以不同的方式進行。

P.S：這不會隨機化您的問題到您的數據庫中。它將qid隨機化，以便從列表中給出一個隨機問題。你可以隨機化你從數據庫中得到的列表，如果你使用HashMap，那麼你會知道一個問題是否曾經出現過。