java - 如何向预制的 Android 程序添加另一个按钮 (Android Studio)

Question

我正在使用这个code但我想让每个问题有 4 个选项。我还把问题减少到了 5 个。有人可以帮忙吗？这是修改后的代码。但它没有运行:(

QuizActivity.java

public class QuestionActivity extends Activity {
    List<Question> quesList;
    int score = 0;
    int qid = 0;
    Question currentQ;
    TextView txtQuestion, times, scored;
    Button button1, button2, button3, button4;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        QuizHelper db = new QuizHelper(this);  
        quesList = db.getAllQuestions();
        currentQ = quesList.get(qid);
        txtQuestion = (TextView) findViewById(R.id.txtQuestion);
        button1 = (Button) findViewById(R.id.button1);
        button2 = (Button) findViewById(R.id.button2);
        button3 = (Button) findViewById(R.id.button3);
        button4 = (Button) findViewById(R.id.button4);
        scored = (TextView) findViewById(R.id.score);
        times = (TextView) findViewById(R.id.timers);
        setQuestionView();
        times.setText("00:02:00");
        CounterClass timer = new CounterClass(60000, 1000);
        timer.start();
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                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());
            }
        });
        button4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                getAnswer(button4.getText().toString());
            }
        });
    }
    public void getAnswer(String AnswerString) {
        if (currentQ.getANSWER().equals(AnswerString)) {
            score++;
            scored.setText("Score : " + score);
        } 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 < 4) {
            currentQ = quesList.get(qid);
            setQuestionView();
        } 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();
        }
    }
    @TargetApi(Build.VERSION_CODES.GINGERBREAD)
    @SuppressLint("NewApi")
    public class CounterClass extends CountDownTimer {
        public CounterClass(long millisInFuture, long countDownInterval) {
            super(millisInFuture, countDownInterval);
        }
        @Override
        public void onFinish() {
            times.setText("Time is up");
        }
        @Override
        public void onTick(long millisUntilFinished) {
            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() {
        txtQuestion.setText(currentQ.getQUESTION());
        button1.setText(currentQ.getOPTA());
        button2.setText(currentQ.getOPTB());
        button3.setText(currentQ.getOPTC());
        button4.setText(currentQ.getOPTD());
        qid++;
    }
}

QuizHelper.java

public class QuizHelper extends SQLiteOpenHelper {
    private static final int DATABASE_VERSION = 1;
    private static final String DATABASE_NAME = "mathsone";
    private static final String TABLE_QUEST = "quest";
    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 static final String KEY_OPTD = "optd"; // option d
    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 " + KEY_OPTD + " TEXT)";
        db.execSQL(sql);
        addQuestion();
        // db.close();
    }
    private void addQuestion() {
        Question q1 = new Question("5+2 = ?", "7", "8", "6", "5", "7");
        this.addQuestion(q1);
        Question q2 = new Question("2+18 = ?", "18", "19", "20", "17", "20");
        this.addQuestion(q2);
        Question q3 = new Question("10-3 = ?", "6", "7", "8", "5", "7");
        this.addQuestion(q3);
        Question q4 = new Question("5+7 = ?", "12", "13", "14", "11", "12");
        this.addQuestion(q4);
        Question q5 = new Question("3-1 = ?", "1", "3", "2", "4", "2");
        this.addQuestion(q5);
        // END
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldV, int newV) {
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_QUEST);
        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());
        values.put(KEY_OPTD, quest.getOPTD());
        // 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));
                quest.setOPTD(cursor.getString(6));
                quesList.add(quest);
            } while (cursor.moveToNext());
        }
        return quesList;
    }
}

问题.java

public class Question extends Activity {
    private int ID;
    private String QUESTION;
    private String OPTA;
    private String OPTB;
    private String OPTC;
    private String OPTD;
    private String ANSWER;
    public Question() {
        ID = 0;
        QUESTION = "";
        OPTA = "";
        OPTB = "";
        OPTC = "";
        OPTD = "";
        ANSWER = "";
    }
    public Question(String qUESTION, String oPTA, String oPTB, String oPTC,String oPTD,
                    String aNSWER) {
        QUESTION = qUESTION;
        OPTA = oPTA;
        OPTB = oPTB;
        OPTC = oPTC;
        OPTD = oPTD;
        ANSWER = aNSWER;
    }
    public int getID() {
        return ID;
    }
    public String getQUESTION() {
        return QUESTION;
    }
    public String getOPTA() {
        return OPTA;
    }
    public String getOPTB() {
        return OPTB;
    }
    public String getOPTC() {
        return OPTC;
    }
    public String getOPTD() {
        return OPTD;
    }
    public String getANSWER() {
        return ANSWER;
    }
    public void setID(int id) {
        ID = id;
    }
    public void setQUESTION(String qUESTION) {
        QUESTION = qUESTION;
    }
    public void setOPTA(String oPTA) {
        OPTA = oPTA;
    }
    public void setOPTB(String oPTB) {
        OPTB = oPTB;
    }
    public void setOPTC(String oPTC) {
        OPTC = oPTC;
    }
    public void setOPTD(String oPTD) {
        OPTD = oPTD;
    }
    public void setANSWER(String aNSWER) {
        ANSWER = aNSWER;
    }
}

然后对于activity_main.xml，我添加了一个id为button4的android按钮。

<Button
       android:id="@+id/button4"
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:layout_gravity="center"
       android:layout_marginLeft="80dp"
       android:layout_marginRight="80dp"
       android:layout_marginTop="5dp"
       android:background="#fff"
       android:gravity="center"
       android:text="31"
       android:textColor="#000000"
       android:textSize="25.0sp" />

这是我的日志:

FATAL EXCEPTION: main
Process: versionone.example, PID: 2252
java.lang.RuntimeException: Unable to start activity ComponentInfo{versionone.example/versionone.example.QuestionActivity}: java.lang.IllegalStateException: Couldn't read row 0, col 6 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.
   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
   at android.app.ActivityThread.access$800(ActivityThread.java:135)
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
   at android.os.Handler.dispatchMessage(Handler.java:102)
   at android.os.Looper.loop(Looper.java:136)
   at android.app.ActivityThread.main(ActivityThread.java:5001)
   at java.lang.reflect.Method.invokeNative(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:515)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
   at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalStateException: Couldn't read row 0, col 6 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.
   at android.database.CursorWindow.nativeGetString(Native Method)
   at android.database.CursorWindow.getString(CursorWindow.java:434)
   at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:51)
   at versionone.example.QuizHelper.getAllQuestions(QuizHelper.java:90)
   at versionone.example.QuestionActivity.onCreate(QuestionActivity.java:38)
   at android.app.Activity.performCreate(Activity.java:5231)
   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)
   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233) 
   at android.app.ActivityThread.access$800(ActivityThread.java:135) 
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 
   at android.os.Handler.dispatchMessage(Handler.java:102) 
   at android.os.Looper.loop(Looper.java:136) 
   at android.app.ActivityThread.main(ActivityThread.java:5001) 
   at java.lang.reflect.Method.invokeNative(Native Method) 
   at java.lang.reflect.Method.invoke(Method.java:515) 
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785) 
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601) 
   at dalvik.system.NativeStart.main(Native Method) 

Answer 1

    + KEY_OPTB + " TEXT, " + KEY_OPTC + " TEXT, " + KEY_OPTD + " TEXT)";

您在表创建 SQL 中的 KEY_OPTC 后面漏掉了一个逗号。