ios AnyObject 到数组？
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AnyObject to Array?
提问by Andrew
I'm using NSJSONSerializationas so:
我是这样使用的NSJSONSerialization：
let twData: AnyObject? = NSJSONSerialization.JSONObjectWithData(responseData, options: NSJSONReadingOptions.MutableLeaves, error: &dataError)
This gives me an AnyObject?.
这给了我一个AnyObject?.
From here, I want to convert it to Array<Dictionary<String,String>>
从这里，我想将其转换为 Array<Dictionary<String,String>>
I've tried all sorts, leading up to this:
我已经尝试了各种方法，导致这个：
var twDataArray: Array<Dictionary<String,String>>? = twData? as? Array<Dictionary<String,String>>
which simply gives the error:
这只是给出了错误：
Type 'Array>' does not conform to protocol 'AnyObject'.
类型“Array>”不符合协议“AnyObject”。
And putting the simpler version:
并放置更简单的版本：
var twDataArray = twData as Array
gives the error:
给出错误：
Cannot convert the expression's type 'AnyObject?' to type 'Array'
无法转换表达式的类型“AnyObject?” 输入“数组”
回答by Vatsal Manot
To cast your data to an array:
要将您的数据转换为数组：
var twDataArray = (twData as! NSArray) as Array
The code above first casts twDatato an NSArray, and then to an Arrayvia a bridging cast. A bridging cast is a special type of cast which converts an Objective-C type to it's _ObjectiveCBridgeableconformant, Swift counterpart.
上面的代码首先转换twData为NSArray，然后Array通过桥接转换为。桥接强制转换是一种特殊类型的强制转换，它将 Objective-C 类型转换为其_ObjectiveCBridgeable符合的 Swift 对应类型。
(Note that I didn't need to write Array<AnyObject>because the element AnyObjectis inferred in the bridging cast from NSArray→ Array)
（请注意，我不需要写，Array<AnyObject>因为元素AnyObject是从NSArray→的桥接转换中推断出来的Array）
Note that the cast above is a forced downcast. Only use this if you're absolutely sure that twDatais going to be an instance of NSArray. Otherwise, use an optional cast.
请注意，上面的转换是强制向下转换。仅当您绝对确定这twData将是NSArray. 否则，请使用可选演员表。
var twDataArray = (twData as? NSArray) as Array?
回答by arango_86
Try the following, you can iterate through the array as given below.
尝试以下操作，您可以遍历数组，如下所示。
for element in twData as! Array<AnyObject> {
print(element)
}
回答by Antonio
This works in a playground:
这适用于操场：
var data: Array<Dictionary<String,String>>? = twData as? Array<Dictionary<String, String>>
the difference from your code is that twDatadoes not require the ?at the end - it is an optional so the as?operator will take care of verifying that it can be case to an array of dictionaries - needless to say, if it's nil, as?will evaluate to nil
与您的代码的不同twData之?处在于，最后不需要- 它是一个可选的，因此as?操作员将负责验证它可以是字典数组的大小写 - 不用说，如果它为零，as?将评估为零
回答by Ankit Tiwari
let twData: Any = NSJSONSerialization.JSONObjectWithData(responseData, options: NSJSONReadingOptions.MutableLeaves, error: &dataError)
Do not use AnyObject. Use Anyinstead of AnyObject. It will work fine. AnyObjectis for all reference type and Array is a value type. That's why this comes. Change it to Any.
不要使用AnyObject. 使用Any代替AnyObject。它会正常工作。AnyObject用于所有引用类型，而 Array 是值类型。这就是为什么会出现这种情况。将其更改为Any.
回答by Mahesh S
As you already know it is a String type you are inserting to something transformable, please do:
正如您已经知道它是一种 String 类型，您要插入到可转换的东西中，请执行以下操作：
if let twoDataArray = twData as? Array<Dictionary<String, String>>{
for data in twoDataArray{
print(data)
}
}
This will guard you from a crashing app when the dictionary is not of type <String,String>.
当字典不是 type 时，这将保护您免受崩溃的应用程序的影响<String,String>。
