Question

如您所见，我想创建一个外部类作为我的活动和数据库之间的适配器，以使其更加安全，只是拒绝使用内部类中的值，我尝试导入值，但导入它们没有意义，而我正试图隐藏它们你能解决这个问题还是给我另一种方法来使我的代码正常工作

public class DataBaseConnection {
    DataBase DataBase;
    public DataBaseConnection(Context context)    {
         DataBase = new DataBase(context);
          public void  dataInsert (String classnumber , String studentsnumber) {
         SQLiteDatabase sqLiteDatabase = dataBase.getWritableDatabase();
            ContentValues contentValues = new ContentValues();
            contentValues.put(DataBase.classname);
            contentValues.put(DataBase.studentsnumber);
        }
    }

    class DataBase  extends SQLiteOpenHelper {
        private static final String database_name = "DB";
        private static final int database_vesion =1;
        private static final String UID = "id";
        private static final String name = "Name";
        private static final String work_mark = "Works Mark";
        private static final String test_mark = "Tests mark";
        private static final String tableName = "Students";
        private static final String classname = "Class name";
        private static final String studentsnumber = "Students number";
        private Context context;
        private static final String tablename1 = "Class";
        private static final String CREATE_TABLE1 = "CREATE TABLE " +tablename1+" " +
                " ("+UID+" INTEGER PRIMARY KEY AUTOINCREMENT," +
                " "+classname+" TEXT VARCHAR(255))," +
                " "+studentsnumber+" INTEGER ;";

        private static final String CREATE_TABLE = "CREATE TABLE " +tableName+" " +
                " ("+UID+" INTEGER PRIMARY KEY AUTOINCREMENT," +
                " "+name+" TEXT VARCHAR(255))," +
                " "+work_mark+" INTEGER ," +
                " "+test_mark+" INTEGER ;";
            private static final String DROP_TABLE = "DROP TABLE IF EXISTS " +tableName;
            private static final String DROP_TABLE1 = "DROP TABLE IF EXISTS "  +tablename1;

        public DataBase(Context context) {
            super(context, database_name,null, database_vesion);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            db.execSQL(CREATE_TABLE);

            db.execSQL(CREATE_TABLE1);
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

            db.execSQL(DROP_TABLE);

            db.execSQL(DROP_TABLE1);

            onCreate(SQLiteDatabase,db);
        }
    }
}

Answer 1

您有两个问题，您已将一个函数放置在一个函数内，该语法无效，它与类变量的可见性无关。另外，由于数据库变量是包作用域的，因此也不能真正确定此方法的安全性。要解决您眼前的问题，您需要这样的东西：

public class DataBaseConnection {

    private final DataBase dataBase;

    public DataBaseConnection(Context context)    {
        dataBase = new DataBase(context);
    }

    public void dataInsert (String classnumber , String studentsnumber) {
        SQLiteDatabase sqLiteDatabase = dataBase.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(DataBase.classname, classnumber);
        contentValues.put(DataBase.studentsnumber, studentsnumber);
        sqLiteDatabase.insert( // insert here  )
    }

.. Rest of class

}

我无法使用我创建的内部类中的外部类中的数据

1 个答案: