Question

我将yes|no|maybe的回复存储到userrelation表中为此，我在DBCONTRACT中创建了一个表，并在db helper类中获取值。

当我获取值并存储到另一个变量时，它会抛出此错误

这是userRelation表

的SQL查询

 public static abstract class RingeeUserRelationTable implements BaseColumns {

        public static final String TABLE_NAME = "user_relation";
        public static final String COL1_EVENT_USER_ID = "EVENT_USER_ID";
        public static final String COL2_EVENT_ID = "EVENT_ID";
        public static final String COL3_RINGEE_USER_ID = "RINGEE_USER_ID";
        public static final String COL4_IS_ATTENDING = "IS_ATTENDING";
        public static final String COL5_IS_DELETE = "IS_DELETE";

        public static final String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME + "(" + _ID + " INTEGER PRIMARY KEY," + COL1_EVENT_USER_ID + INTEGER_TYPE + COMMA_SEP + COL2_EVENT_ID + INTEGER_TYPE
                + COMMA_SEP + COL3_RINGEE_USER_ID + INTEGER_TYPE + COMMA_SEP + COL4_IS_ATTENDING + INTEGER_TYPE + COMMA_SEP + COL5_IS_DELETE + INTEGER_TYPE + ")";

        public static final String DELETE_TABLE = "DROP TABLE IF EXISTS " + TABLE_NAME;

        public static final String RETRIVE_ALL_USER_DATA = "SELECT " + COL1_EVENT_USER_ID + COMMA_SEP + COL2_EVENT_ID + COMMA_SEP + COL3_RINGEE_USER_ID + COMMA_SEP + COL4_IS_ATTENDING + COMMA_SEP
                + COL5_IS_DELETE + " FROM " + TABLE_NAME;
    }

这是获取值并设置为userMOS列表

的代码

public ArrayList<UserMO> getAllUserRelation() {
        ArrayList<UserMO> userMOs = new ArrayList<UserMO>();
        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = db.rawQuery(DatabaseContract.RingeeUserRelationTable.RETRIVE_ALL_USER_DATA, null );
        if (cursor.moveToFirst()) {
            do {
                UserMO userMO = new UserMO();
                userMO.setEventUserId(cursor.getLong(1));
                userMO.setEventId(cursor.getLong(2));
                userMO.setRingeeUserId(cursor.getLong(3));
                userMO.setIsAttending(cursor.getInt(4));
                userMO.setIsDelete(cursor.getInt(5));
                userMOs.add(userMO);
            } while (cursor.moveToNext());

            cursor.close();
        }
        return userMOs;
    }

这是在片段中获取isattending值的代码

    context = getActivity().getApplicationContext();
            dbHelper = new DatabaseHelper(context);
            userMOs = dbHelper.getAllUserRelation();
// I got the error here there is no value in a table but in back end the values are stored 
    int  isAttending = userMOs.get(position).getIsAttending();

我正在使用此isattending来设置yes|no|maybe按钮

的颜色

  switch(isAttending)
            {
                case 1:
                    yesBtn.setBackgroundColor(Color.YELLOW);
                    noBtn.setBackgroundColor(Color.BLUE);
                    maybeBtn.setBackgroundColor(Color.BLUE);
                    break;
                case 2:
                    yesBtn.setBackgroundColor(Color.BLUE);
                    noBtn.setBackgroundColor(Color.BLUE);
                    maybeBtn.setBackgroundColor(Color.YELLOW);
                    break;
                case 0:
                    yesBtn.setBackgroundColor(Color.BLUE);
                    noBtn.setBackgroundColor(Color.YELLOW);
                    maybeBtn.setBackgroundColor(Color.BLUE);
                    break;
            }

当我运行这个项目时，我收到一个错误：IndexOutOfBoundsException 请告诉我错误的原因是什么以及如何解决这个问题

Answer 1

索引 0基于 因此，您需要像这样重写代码：

public ArrayList<UserMO> getAllUserRelation() {
    ArrayList<UserMO> userMOs = new ArrayList<UserMO>();
    SQLiteDatabase db = this.getReadableDatabase();

    Cursor cursor = db.rawQuery(DatabaseContract.RingeeUserRelationTable.RETRIVE_ALL_USER_DATA, null );
    if (cursor.moveToFirst()) {
        do {
            UserMO userMO = new UserMO();
            userMO.setEventUserId(cursor.getLong(0));
            userMO.setEventId(cursor.getLong(1));
            userMO.setRingeeUserId(cursor.getLong(2));
            userMO.setIsAttending(cursor.getInt(3));
            userMO.setIsDelete(cursor.getInt(4));
            userMOs.add(userMO);
        } while (cursor.moveToNext());

        cursor.close();
    }
    return userMOs;
}

Answer 2

编写如下代码： -

public ArrayList<UserMO> getAllUserRelation() {
        ArrayList<UserMO> userMOs = new ArrayList<UserMO>();
        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = db.rawQuery(DatabaseContract.RingeeUserRelationTable.RETRIVE_ALL_USER_DATA, null );
        if (cursor.moveToFirst()) {
            do {
                UserMO userMO = new UserMO();
                userMO.setEventUserId(cursor.getLong(1));
                userMO.setEventId(cursor.getLong(2));
                userMO.setRingeeUserId(cursor.getLong(3));
                userMO.setIsAttending(cursor.getInt(4));
                userMO.setIsDelete(cursor.getInt(5));
                userMos.add(userMO);
            } while (cursor.moveToNext());

            cursor.close();
        }
        return userMOs;
    }

它为您提供了一个超出绑定异常的数组索引，因为您没有为数组列表指定任何内容。我在上面的代码中添加了这一行。

userMos.add(userMo);

如何修复IndexOutOfBoundsException：无效的索引0大小为0

2 个答案: