如何将图像合并到SQLite测验中? [英] How to incorporate images into SQLite quiz?

问题描述

我正在制作一个测验应用程序以向自己介绍android开发，并希望能够提出有关图像的问题(即，出现图像并且询问用户它是什么，等等).我正在使用SQLite数据库存储问题，所以我的问题是，每次加载新问题时，如何使出现该问题的图像出现?".

I am making a quiz app to introduce myself to android development and would like to be able to ask questions about images (ie, an image appears and the user is asked what it is etc). I am using an SQLite db to store the questions, so my question is, "How do I make the image that the question is about appear each time a new question is loaded?".

这是我的问题课

public class Question {
    private String question;
    private String option1;
    private String option2;
    private String option3;
    private int answerNr;

    public Question(){}

    public Question(String question, String option1, String option2, String option3, int answerNr) {
        this.question = question;
        this.option1 = option1;
        this.option2 = option2;
        this.option3 = option3;
        this.answerNr = answerNr;
    }

    public String getQuestion() {
        return question;
    }

    public void setQuestion(String question) {
        this.question = question;
    }

    public String getOption1() {
        return option1;
    }

    public void setOption1(String option1) {
        this.option1 = option1;
    }

    public String getOption2() {
        return option2;
    }

    public void setOption2(String option2) {
        this.option2 = option2;
    }

    public String getOption3() {
        return option3;
    }

    public void setOption3(String option3) {
        this.option3 = option3;
    }

    public int getAnswerNr() {
        return answerNr;
    }

    public void setAnswerNr(int answerNr) {
        this.answerNr = answerNr;
    }
}

这是我正在使用的dbHelper

And this is the dbHelper I'm using

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

    @Override
    public void onCreate(SQLiteDatabase db) {
        this.db = db;

        final String SQL_CREATE_QUESTIONS_TABLE = "CREATE TABLE " +
                QuestionsTable.TABLE_NAME + " ( " +
                QuestionsTable._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
                QuestionsTable.COLUMN_QUESTION + " TEXT, " +
                QuestionsTable.COLUMN_OPTION1 + " TEXT, " +
                QuestionsTable.COLUMN_OPTION2 + " TEXT, " +
                QuestionsTable.COLUMN_OPTION3 + " TEXT, " +
                QuestionsTable.COLUMN_ANSWER_NR + " INTEGER" +
                ")";

        db.execSQL(SQL_CREATE_QUESTIONS_TABLE);
        fillQuestionsTable();
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + QuestionsTable.TABLE_NAME);
        onCreate(db);
    }

    private void fillQuestionsTable(){
        Question q1 = new Question("How often do blackbeard mains deserve the kill?", "Always", "Sometimes", "Never", 3);
        addQuestion(q1);
        Question q2 = new Question("How fast is Ash?", "3 speed", "9 speed", "2 speed", 1);
        addQuestion(q2);
        Question q3 = new Question("How thicc is Rook?", "2 armor", "3 armor", "9 armor", 2);
        addQuestion(q3);
    }

    private void addQuestion(Question question){
        ContentValues cv = new ContentValues();
        cv.put(QuestionsTable.COLUMN_QUESTION, question.getQuestion());
        cv.put(QuestionsTable.COLUMN_OPTION1, question.getOption1());
        cv.put(QuestionsTable.COLUMN_OPTION2, question.getOption2());
        cv.put(QuestionsTable.COLUMN_OPTION3, question.getOption3());
        cv.put(QuestionsTable.COLUMN_ANSWER_NR, question.getAnswerNr());
        db.insert(QuestionsTable.TABLE_NAME, null, cv);
    }

    public List<Question> getAllQuestions() {
        List<Question> questionList = new ArrayList<>();
        db = getReadableDatabase();
        Cursor c = db.rawQuery("SELECT * FROM " + QuestionsTable.TABLE_NAME, null);
        if (c.moveToFirst()) {
            do {
                Question question = new Question();
                question.setQuestion(c.getString(c.getColumnIndex(QuestionsTable.COLUMN_QUESTION)));
                question.setOption1(c.getString(c.getColumnIndex(QuestionsTable.COLUMN_OPTION1)));
                question.setOption2(c.getString(c.getColumnIndex(QuestionsTable.COLUMN_OPTION2)));
                question.setOption3(c.getString(c.getColumnIndex(QuestionsTable.COLUMN_OPTION3)));
                question.setAnswerNr(c.getInt(c.getColumnIndex(QuestionsTable.COLUMN_ANSWER_NR)));
                questionList.add(question);
            } while (c.moveToNext());
        }

        c.close();
        return questionList;
    }
}

我的QuizActivity(至少相关位)

My QuizActivity (The relevant bits at least)

public class QuizActivity extends AppCompatActivity {

    private TextView textViewQuestion;
    private TextView textViewScore;
    private TextView textViewQuestionCount;
    private TextView textViewTimer;
    private RadioGroup rbGroup;
    private RadioButton rb1;
    private RadioButton rb2;
    private RadioButton rb3;
    private Button buttonConfirmNext;

    private ColorStateList textColorDefaultRb;

    private List<Question> questionList;
    private int questionCounter;
    private int questionCountTotal;
    private Question currentQuestion;

    private int score;
    private boolean answered;

    private long backPressedTime;

    RadioGroup answers;
    RadioButton radioButton;

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

        textViewQuestion = findViewById(R.id.question);
        textViewScore = findViewById(R.id.score);
        textViewQuestionCount = findViewById(R.id.question_num);
        textViewTimer = findViewById(R.id.timer);
        rbGroup = findViewById(R.id.answers);
        rb1 = findViewById(R.id.option_1);
        rb2 = findViewById(R.id.option_2);
        rb3 = findViewById(R.id.option_3);
        buttonConfirmNext = findViewById(R.id.confirm);

        textColorDefaultRb = rb1.getTextColors();

        QuizDbHelper dbHelper = new QuizDbHelper(this);
        questionList = dbHelper.getAllQuestions();
        questionCountTotal = questionList.size();
        Collections.shuffle(questionList);

        showNextQuestion();
...
...
...
...
...

private void showNextQuestion(){
        rb1.setTextColor(textColorDefaultRb);
        rb2.setTextColor(textColorDefaultRb);
        rb3.setTextColor(textColorDefaultRb);
        rbGroup.clearCheck();

        if (questionCounter < questionCountTotal){
            currentQuestion = questionList.get(questionCounter);

            textViewQuestion.setText(currentQuestion.getQuestion());
            rb1.setText(currentQuestion.getOption1());
            rb2.setText(currentQuestion.getOption2());
            rb3.setText(currentQuestion.getOption3());

            questionCounter++;
            textViewQuestionCount.setText("Question: " + questionCounter + "/" + questionCountTotal);
            answered = false;
            buttonConfirmNext.setText("Confirm");
        }
        else {
            finishQuiz();
        }
    }

我用来存储一些常量的"QuizContract"

And my "QuizContract" I'm using to store a few constants

private QuizContract() {}

    public static class QuestionsTable implements BaseColumns {
        public static final String TABLE_NAME = "quiz_questions";
        public static final String COLUMN_QUESTION = "question";
        public static final String COLUMN_OPTION1 = "option1";
        public static final String COLUMN_OPTION2 = "option2";
        public static final String COLUMN_OPTION3 = "option3";
        public static final String COLUMN_ANSWER_NR = "answer_nr";
    }
}

推荐答案

您可以将图像转换为base64并将其保存到SQLite，并且在检索时可以将其转换回位图.这是转换代码.

You can convert image to base64 and save it to SQLite and on retrival, you can convert it back to bitmap. Here is a code for the conversion.

   //encode image to base64 string
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.logo);
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
        byte[] imageBytes = baos.toByteArray();
        String imageString = Base64.encodeToString(imageBytes, Base64.DEFAULT);

        //decode base64 string to image
        imageBytes = Base64.decode(imageString, Base64.DEFAULT);
        Bitmap decodedImage = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length);
        image.setImageBitmap(decodedImage);

希望这对您有用.

这篇关于如何将图像合并到SQLite测验中?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！