如何在没有重复的

时间:2016-03-13 08:06:07

标签: java android sqlite

这是我执行问题的活动

我不知道应该在哪里编码以及我应该使用什么代码来随机提出一个问题而不会有任何重复的问题(我相信它的qid)。

package com.example.testing;

import java.util.List;
import java.util.Random;
import java.util.Timer;
import java.util.concurrent.TimeUnit;
import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Typeface;
import android.media.MediaPlayer;
import android.os.Build;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class QuestionActivity extends Activity{

    List<Question> quesList;
    int score = 0;
    int qid = 0;
    int lives = 5;




    Question currentQ;
    TextView txtQuestion, times, scored, livess;
    Button button1, button2, button3;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        QuizHelper db = new QuizHelper(this);  // my question bank class
        quesList = db.getAllQuestions();  // this will fetch all quetonall questions
        currentQ = quesList.get(qid); // the current question
        txtQuestion = (TextView) findViewById(R.id.txtQuestion);
        // the textview in which the question will be displayed
        // the three buttons,
        // the idea is to set the text of three buttons with the options from question bank
        button1 = (Button) findViewById(R.id.button1);
        button2 = (Button) findViewById(R.id.button2);
        button3 = (Button) findViewById(R.id.button3);

        livess = (TextView) findViewById(R.id.livess);
        // the textview in which  will be displayed
        scored = (TextView) findViewById(R.id.score);
        // the timer
        times = (TextView) findViewById(R.id.timers);
        // method which will set the things up for our game
        setQuestionView();
        times.setText("00:02:00");
        // A timer of 60 seconds to play for, with an interval of 1 second (1000 milliseconds)
        CounterClass timer = new CounterClass(60000, 1000);
        timer.start();
        // button click listeners
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // passing the button text to other method
                // to check whether the anser is correct or not
                // same for all three buttons
                getAnswer(button1.getText().toString());
            }
        });
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                getAnswer(button2.getText().toString());
            }
        });
        button3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                getAnswer(button3.getText().toString());
            }
        });
    }
    public void getAnswer(String AnswerString) {
        if (currentQ.getANSWER().equals(AnswerString)) {
            // if conditions matches increase the int (score) by 1
            // and set the text of the score view
            score++;
            scored.setText("Score : " + score);




        } else if(lives > 1){
            lives--;
            livess.setText("Lives: " + lives);

        }
        else {
            Intent intent = new Intent(QuestionActivity.this,
                    ResultActivity.class);
            Bundle b = new Bundle();
            b.putInt("score", score); // Your score
            intent.putExtras(b); // Put your score to your next
            startActivity(intent);
            finish();


        }

        {


        }
        if (qid < 20) {
            // if questions are not over then do this
            currentQ = quesList.get(qid);
            setQuestionView();
        } else {
            // if over do this
            Intent intent = new Intent(QuestionActivity.this,
                    ResultActivity.class);
            Bundle b = new Bundle();
            b.putInt("score", score); // Your score
            intent.putExtras(b); // Put your score to your next
            startActivity(intent);
            finish();
        }
    }
    @TargetApi(Build.VERSION_CODES.GINGERBREAD)
    @SuppressLint("NewApi")
    public class CounterClass extends CountDownTimer {
        public CounterClass(long millisInFuture, long countDownInterval) {
            super(millisInFuture, countDownInterval);
            // TODO Auto-generated constructor stub
        }
        @Override
        public void onFinish() {
            times.setText("Time is up");
        }
        @Override
        public void onTick(long millisUntilFinished) {
            // TODO Auto-generated method stub
            long millis = millisUntilFinished;
            String hms = String.format(
                    "%02d:%02d:%02d",
                    TimeUnit.MILLISECONDS.toHours(millis),
                    TimeUnit.MILLISECONDS.toMinutes(millis)
                            - TimeUnit.HOURS.toMinutes(TimeUnit.MILLISECONDS
                            .toHours(millis)),
                    TimeUnit.MILLISECONDS.toSeconds(millis)
                            - TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS
                            .toMinutes(millis)));
            System.out.println(hms);
            times.setText(hms);
        }
    }
    private void setQuestionView() {
        // the method which will put all things together
        txtQuestion.setText(currentQ.getQUESTION());
        button1.setText(currentQ.getOPTA());
        button2.setText(currentQ.getOPTB());
        button3.setText(currentQ.getOPTC());
        qid++;
    }
}

这是我的问题和答案的数据库我使用的是sqlite我不知道我应该在哪里编码来随机搜索问题。

package com.example.testing;

import java.util.ArrayList;
import java.util.List;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class QuizHelper extends SQLiteOpenHelper {
    private static final int DATABASE_VERSION = 1;
    // Database Name
    private static final String DATABASE_NAME = "mathsone";
    // tasks table name
    private static final String TABLE_QUEST = "quest";
    // tasks Table Columns names
    private static final String KEY_ID = "qid";
    private static final String KEY_QUES = "question";
    private static final String KEY_ANSWER = "answer"; // correct option
    private static final String KEY_OPTA = "opta"; // option a
    private static final String KEY_OPTB = "optb"; // option b
    private static final String KEY_OPTC = "optc"; // option c
    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_QUES
                + " TEXT, " + KEY_ANSWER + " TEXT, " + KEY_OPTA + " TEXT, "
                + KEY_OPTB + " TEXT, " + KEY_OPTC + " TEXT)";
        db.execSQL(sql);
        addQuestion();
        // db.close();
    }
    private void addQuestion() {
        Question q1 = new Question("5+2 = ?", "7", "8", "6", "7");
        this.addQuestion(q1);
        Question q2 = new Question("2+18 = ?", "18", "19", "20", "20");
        this.addQuestion(q2);
        Question q3 = new Question("10-3 = ?", "6", "7", "8", "7");
        this.addQuestion(q3);
        Question q4 = new Question("5+7 = ?", "12", "13", "14", "12");
        this.addQuestion(q4);
        Question q5 = new Question("3-1 = ?", "1", "3", "2", "2");
        this.addQuestion(q5);
        Question q6 = new Question("0+1 = ?", "1", "0", "10", "1");
        this.addQuestion(q6);
        Question q7 = new Question("9-9 = ?", "0", "9", "1", "0");
        this.addQuestion(q7);
        Question q8 = new Question("3+6 = ?", "8", "7", "9", "9");
        this.addQuestion(q8);
        Question q9 = new Question("1+5 = ?", "6", "7", "5", "6");
        this.addQuestion(q9);
        Question q10 = new Question("7-5 = ?", "3", "2", "6", "2");
        this.addQuestion(q10);
        Question q11 = new Question("7-2 = ?", "7", "6", "5", "5");
        this.addQuestion(q11);
        Question q12 = new Question("3+5 = ?", "8", "7", "5", "8");
        this.addQuestion(q12);
        Question q13 = new Question("0+6 = ?", "7", "6", "5", "6");
        this.addQuestion(q13);
        Question q14 = new Question("12-10 = ?", "1", "2", "3", "2");
        this.addQuestion(q14);
        Question q15 = new Question("12+2 = ?", "14", "15", "16", "14");
        this.addQuestion(q15);
        Question q16 = new Question("2-1 = ?", "2", "1", "0", "1");
        this.addQuestion(q16);
        Question q17 = new Question("6-6 = ?", "6", "12", "0", "0");
        this.addQuestion(q17);
        Question q18 = new Question("5-1 = ?", "4", "3", "2", "4");
        this.addQuestion(q18);
        Question q19 = new Question("4+2 = ?", "6", "7", "5", "6");
        this.addQuestion(q19);
        Question q20 = new Question("5+1 = ?", "6", "7", "5", "6");
        this.addQuestion(q20);
        Question q21 = new Question("5-4 = ?", "5", "4", "1", "1");
        this.addQuestion(q21);
        // END
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldV, int newV) {
        // Drop older table if existed
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_QUEST);
        // Create tables again
        onCreate(db);
    }
    // Adding new question
    public void addQuestion(Question quest) {
        // SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(KEY_QUES, quest.getQUESTION());
        values.put(KEY_ANSWER, quest.getANSWER());
        values.put(KEY_OPTA, quest.getOPTA());
        values.put(KEY_OPTB, quest.getOPTB());
        values.put(KEY_OPTC, quest.getOPTC());
        // Inserting Row
        dbase.insert(TABLE_QUEST, null, values);
    }
    public List<Question> getAllQuestions() {
        List<Question> quesList = new ArrayList<Question>();
        // Select All Query
        String selectQuery = "SELECT  * FROM " + TABLE_QUEST;
        dbase = this.getReadableDatabase();
        Cursor cursor = dbase.rawQuery(selectQuery, null);
        // looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
                Question quest = new Question();
                quest.setID(cursor.getInt(0));
                quest.setQUESTION(cursor.getString(1));
                quest.setANSWER(cursor.getString(2));
                quest.setOPTA(cursor.getString(3));
                quest.setOPTB(cursor.getString(4));
                quest.setOPTC(cursor.getString(5));
                quesList.add(quest);
            } while (cursor.moveToNext());
        }
        // return quest list
        return quesList;
    }
}

2 个答案:

答案 0 :(得分:1)

List<Question> quesList;  //This is a array of question

quesList = db.getAllQuestions();  // this will fetch all quetonall questions from database

currentQ = quesList.get(qid);    // this is the current question at present its at 0th position(i.e first question)

您在此方法中显示textview上的问题

private void setQuestionView() { 
       // the method which will put all things together 
       txtQuestion.setText(currentQ.getQUESTION());
       button1.setText(currentQ.getOPTA());
       button2.setText(currentQ.getOPTB());
       button3.setText(currentQ.getOPTC());
       qid++;
} 

如果您需要显示随机问题,

quesList = db.getAllQuestions();   //array of questions

Random random = new Random();    // to get random array

currentQ = random.nextInt(quesList.size());   //assign random question to current question.

在textview上显示将由setQuestionView()方法

处理

答案 1 :(得分:0)

  • 要跟踪已使用的问题,请创建ArrayList<Integer> questionsDone

  • 要生成随机问题,请创建java.util.Random类的对象,并获得随机整数,直至数据库中的问题数

    int totalQuestions = cursor.getCount();并使用获取新的问题ID int questionId = random.nextInt(totalQuestions);

  • 在将其显示给用户之前,请检查它是否包含在questionsDone数组中。如果包含然后生成另一个问题,因为它是重复的问题。