如何从Swift中的Parse查询结果访问对象的字段? [英] How do you access an object's fields from a Parse query result in Swift?

问题描述

Parse文档提供了使用Swift进行查询的示例，并显示了访问诸如objectId或count之类的内置字段的示例，但是如何访问对象的列之一呢?

The Parse documentation provides examples of queries using Swift, and they show an example accessing a built-in field like objectId or count, but what about accessing one of the columns of the object?

    var query = PFQuery(className: "MyObject")
    query.findObjectsInBackgroundWithBlock {
            (objects: [AnyObject]!, error: NSError!) -> Void in
            if !(error != nil) {
                for object in objects {
                    println(object["name"])
            }
            else {
                println("%@", error)
            }
    }

获取错误"AnyObject"无法转换为字符串.

Gets the error "AnyObject" is not convertible to string.

object.objectForKey("name")

还给出了一个错误:找不到接受提供的参数的'objectForKey'的重载"

Also gives an error: "Could not find an overload for 'objectForKey' that accepts the supplied arguments"

现在我还尝试了"as PFObject"或类似的方法，但是它也会导致错误，而且Parse的文档没有显示类似的内容. 类型'[AnyObject]'不能隐式向下转换为'PFObject'；您是要使用'as'来强制向下转换吗?"

Now I also tried "as PFObject" or something similar, but it also results in errors plus Parse's documentation doesn't show anything like that. "Type '[AnyObject]' cannot be implicitly downcast to 'PFObject'; did you mean to use 'as' to force downcast?"

然后我应用此修复程序，新的错误是类型'PFObject'不符合协议'SequenceType'

Then I apply the fix, the new error is "Type 'PFObject' does not conform to protocol 'SequenceType'

还尝试了在循环内向下投射

Tried also downcasting inside the loop with

let pf = object as PFObject

但这似乎无济于事，因为当我这样做

but that doesn't seem to help because when I do

let name = pf["name"]

我得到'AnyObject'无法转换为'String'"

I get "'AnyObject' is not convertible to 'String'"

感谢您的帮助.我确定我遗漏了一些明显的东西，因为我还没有发现任何东西.

Thanks for your help. I'm sure I'm missing something obvious, since I haven't found anything yet;

推荐答案

您需要显式转换要检索的属性-

You need to explicitly cast the attribute you are retrieving -

let name = pf["name"] as String

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