Question

我正在尝试使用查询删除对象。但是我收到了一个沮丧的错误，说[PFObject]的Downcast只是打开选项你是不是意味着使用！？

 var query: PFQuery = PFQuery(className: "Posts")
    query.whereKey("deleteID", containsString: selectedObjId)

    query.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
        for object in (objects as! [PFObject]) {

            if error == nil {
                //Hide activity indicator and go back to collection view when done deleting
                object.delete() // 削除
                self.hideActivityIndicator(self.view)
                self.quitButtonPressed()

            }
        }
    }

Answer 1

似乎返回的objects属于[PFObject]?类型，因此代替向下展开只需打开对象

query.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
   if error == nil {
      for object in objects! {
         do {
           //Hide activity indicator and go back to collection view when done deleting
           try object.delete() // 削除
         } catch let error as NSError {
           print(error)
         }
      }
      self.hideActivityIndicator(self.view)
      self.quitButtonPressed()
  } else {
    print(error!)
  }
}

你还应该检查错误是否之前重复循环和隐藏指示符的行并按下按钮应该执行一次重复之后循环。

查询中的向下转错误

1 个答案: