ios - 使用 Parse 在 iOS Swift 中更新对象

Question

我有一个“首选项”表，其中用户首选项与用户名一起保存。我创建了这个方法来更新当前用户的偏好'但不知何故它似乎不起作用。我不确定是否需要“prefQuery.getObjectInBackgroundWithId(object.objectId)”部分。

我是 Parse 的新手，有人可以帮我指出可能是什么问题吗。

func userPreferences(){
    var currUser = PFUser.currentUser()
    var prefQuery = PFQuery(className: "preferences")
    var prefObj = PFObject(className: "preferences")

    if let currUserName = PFUser.currentUser()?.username {
        prefQuery.whereKey("username", equalTo: currUserName)
    }

    prefQuery.findObjectsInBackgroundWithBlock {
        (objects: [AnyObject]?, error: NSError?) -> Void in

        if error == nil {
            if let objects = objects as? [PFObject] {
                for object in objects {

                    prefQuery.getObjectInBackgroundWithId(object.objectId){
                        (object: PFObject?, error: NSError?) -> Void in
                        if error == nil || object != nil {
                            prefObj["agestart"] = self.fromAge.text
                            prefObj["ageend"] = self.toAge.text
                            prefObj["location"] = self.location.text
                            ProgressHUD.showSuccess("Update successful")
                        } else {
                            ProgressHUD.showError("Update failed")
                        }
                    }
                }
            }
        }
    }
}

Answer 1

我发现了问题并更新了我的代码。工作代码如下；问题出在“prefObj["agestart"]”代码块上，我在其中使用了错误的查询实例。您可以比较这两个片段:

func userPreferences(){
    var currUser = PFUser.currentUser()
    var prefQuery = PFQuery(className: "preferences")
    var prefObj = PFObject(className: "preferences")

    if let currUserName = PFUser.currentUser()?.username {
        prefQuery.whereKey("username", equalTo: currUserName)
    }

    prefQuery.findObjectsInBackgroundWithBlock {
        (objects: [AnyObject]?, error: NSError?) -> Void in

        if error == nil {
            if let objects = objects as? [PFObject] {
                for object in objects {
                    prefQuery.getObjectInBackgroundWithId(object.objectId){
                        (prefObj: PFObject?, error: NSError?) -> Void in
                        if error != nil {
                            println(error)
                            ProgressHUD.showSuccess("Error while updating")
                        } else if let prefObj = prefObj {
                            prefObj["agestart"] = self.fromAge.text
                            prefObj["ageend"] = self.toAge.text
                            prefObj["location"] = self.location.text
                                ProgressHUD.showSuccess("Update successful")
                            prefObj.saveInBackgroundWithBlock({ (Bool, error: NSError!) -> Void in })
                        }
                    }
                }
            }
        }
    }
}