Java 如何将图像合并到SQLite测试中？

我正在制作一个测验应用程序来介绍我自己的android开发，并希望能够询问有关图像的问题（例如，出现一个图像，并询问用户它是什么等）。我使用SQLite数据库来存储问题，所以我的问题是，“如何使问题涉及的图像在每次加载新问题时都出现？”

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;
    }
}

这就是我正在使用的dbHelper

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;
    }
}

---

您可以将图像转换为

base64

并将其保存到SQLite，在检索时，您可以将其转换回位图。下面是转换的代码

   //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。

您的编码标准必须临时制定！

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";
    }
}

   //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);