getReadableDatabase（）上的NullPointerException

由于不是活动的类

this.getReadableDatabase();

使用上下文打开数据库。尝试以下：

DatabaseHandler dbz = new DatabaseHandler(Activity.this);public Context context;public DatabaseHandler(Context context) {    super(context, DATAbase_NAME, null, DATAbase_VERSION);    // assigning context Change your constructor    this.context = context;}// Open database using context objectSQLiteDatabase db = this.getReadableDatabase();