如何从SQlite数据库中获取按钮单击的上一个和下一个数据

Question

我正在研究QuizActivity并且无法从最后一个问题到达时从数据库获取上一个问题，然后点击上一个按钮然后第一个问题出现在活动中。最近2天需要帮助。感谢

  DATABASE

   public List<NotificationListItem> getNQuestions() {
   List<NotificationListItem> quest = new ArrayList<NotificationListItem>();
   String selectQuery = "SELECT  * FROM " + TABLE_NAME2;
   openToRead();
   Cursor cursor = db.rawQuery(selectQuery, null);
   if (cursor.moveToFirst()) {
        do {
            NotificationListItem item = new NotificationListItem();
            item.setqID(cursor.getInt(1));
            item.setAnswer(cursor.getString(2));
            item.setTestID(cursor.getString(3));
            item.setquestions(cursor.getString(4));
            item.setOption1(cursor.getString(5));
            item.setOption2(cursor.getString(6));
            item.setOption3(cursor.getString(7));
            item.setOption4(cursor.getString(8));
            item.setOption5(cursor.getString(9));
            item.setAnscount(cursor.getString(10));
            item.setTc(cursor.getString(11));
            quest.add(item);
        } while (cursor.moveToNext());
    }
    return quest;
}

public List<NotificationListItem> getPQuestions() {
    List<NotificationListItem> quest = new ArrayList<NotificationListItem>();
    String selectQuery = "SELECT  * FROM " + TABLE_NAME2;
    openToRead();
    Cursor cursor = db.rawQuery(selectQuery, null);
    if (cursor.moveToFirst()) {
        do {
            NotificationListItem pitem = new NotificationListItem();
            pitem.setqID(cursor.getInt(1));
            pitem.setAnswer(cursor.getString(2));
            pitem.setTestID(cursor.getString(3));
            pitem.setquestions(cursor.getString(4));
            pitem.setOption1(cursor.getString(5));
            pitem.setOption2(cursor.getString(6));
            pitem.setOption3(cursor.getString(7));
            pitem.setOption4(cursor.getString(8));
            pitem.setOption5(cursor.getString(9));
            pitem.setAnscount(cursor.getString(10));
            pitem.setTc(cursor.getString(11));
            quest.add(pitem);
        } while (cursor.moveToNext());
    }
    return quest;
}
public int getpreviousid() {
    int previd=0;
    openToRead();
    String selectQuery = "SELECT * FROM " + TABLE_NAME2;
    Cursor cursor=null;
    cursor = db.rawQuery(selectQuery, null);
    if (cursor != null && cursor.moveToPrevious()) {
        previd=cursor.getInt(cursor.getColumnIndex(KEY_QID));
    }
        cursor.close();
    return previd;
}


QUIZACTIVITY

NotificationListItem Nitem,Pitem;
List<NotificationListItem> Nquest,Pquest;
int score=0;
int qID=0,anscount,totalchoice,tq,questionid,previd;
QuizTable quizTable;
LinearLayout rc;

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

    qs = getIntent().getStringExtra("questions");
    tq = Integer.parseInt(qs);
    prevBT.setEnabled(false);
    quizTable = new QuizTable(this);
    quizTable.openToRead();
    quizTable.openToWrite();
    Nquest=quizTable.getNQuestions();
    Pquest=quizTable.getPQuestions();
    lastid=quizTable.getLastId();
    firstid=quizTable.getFirstId();
    previd=quizTable.getpreviousid();
    Nitem=Nquest.get(questionid);
    Pitem=Pquest.get(previd);

    setQuestionView();

    nextBT.setOnClickListener(new View.OnClickListener() {      
        @Override
        public void onClick(View v) {

            if(questionid<Integer.parseInt(lastid)){                    
                Nitem=Nquest.get(questionid);
                prevBT.setEnabled(true);
                setQuestionView();      
            }  
            else{  
                Intent intent = new Intent(QuizActivityB.this, TestAnalysisActivity.class);
                startActivity(intent);
                finish();
            }}
    });

    prevBT.setOnClickListener(new View.OnClickListener() {      
        @Override
        public void onClick(View v) {

            if(questionid<Integer.parseInt(lastid)){                    
                    Pitem=Pquest.get(previd);
                    questionid=previd;
                    setQuestionView1(); 

            }
            if(questionid==Integer.parseInt(lastid))
            {
                 Pitem=Pquest.get(previd);
                 questionid=previd;
                 setQuestionView1();    
            }
            }
    });
}

private void setQuestionView()
{

    txtQuestion.setText(Nitem.getquestions());

      op1=(Nitem.getOption1());
      op2=(Nitem.getOption2());
      op3=(Nitem.getOption3());
      op4=(Nitem.getOption4());
      op5=(Nitem.getOption5());
      ansc=Nitem.getAnscount();
      tc=(Nitem.getTc());
      questionid=(Nitem.getqID());
      if(questionid==Integer.parseInt(firstid))
        {
            prevBT.setEnabled(false);
        }
      totalchoice=Integer.parseInt(tc);
      anscount=Integer.parseInt(ansc);
      System.out.println("QUESTIONID="+questionid);

      if(anscount==1)
        {
        rc.removeAllViews();
        addRadioButtons();
        }
        else if(anscount>1)
        {
        rc.removeAllViews();
        addCheckButtons();
        }}

private void setQuestionView1() {
    // TODO Auto-generated method stub
    if(questionid==Integer.parseInt(firstid))
    {
        prevBT.setEnabled(false);
    }
    txtQuestion.setText(Pitem.getquestions());
      op1=(Pitem.getOption1());
      op2=(Pitem.getOption2());
      op3=(Pitem.getOption3());
      op4=(Pitem.getOption4());
      op5=(Pitem.getOption5());
      ansc=Pitem.getAnscount();
      tc=(Pitem.getTc());
      questionid=(Pitem.getqID());
      totalchoice=Integer.parseInt(tc);
      anscount=Integer.parseInt(ansc);
      System.out.println("PREVIOUSID="+ questionid);

      if(anscount==1)
        {
        rc.removeAllViews();
        addRadioButtons();
        }
        else if(anscount>1)
        {
        rc.removeAllViews();
        addCheckButtons();
        }
    }

Answer 1

我们按下Next，这意味着显然增加了questionID：

 nextBT.setOnClickListener(new View.OnClickListener() {      
        @Override
        public void onClick(View v) {
            questionid++; // MISSING IN UR CODE
            if(questionid<Integer.parseInt(lastid)){                    
                Nitem=Nquest.get(questionid);
                prevBT.setEnabled(true);
                setQuestionView();      
            }  
            else{  
                Intent intent = new Intent(QuizActivityB.this, TestAnalysisActivity.class);
                startActivity(intent);
                finish();
            }}
    });