Question

如果尝试获取字符串对象

，则（Xcode6 BETA 6）出错

let jsonString : String = "[{\"name\":[\"Fred\",\"John\"],\"age\":21},{\"name\":\"Bob\",\"age\":35}]"

let myData:NSData? = jsonString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)

var jsonResult:NSArray = NSJSONSerialization.JSONObjectWithData(myData!, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSArray

println(jsonResult.objectAtIndex(0).objectForKey("name").objectAtIndex(0))

打印永远不会被调用，导致错误。有人有想法吗？

Answer 1

从NSDictionary或NSArray获取值返回AnyObject对象。所以你应该输入适当的类型。试试这个

println(((jsonResult.objectAtIndex(0) as NSDictionary).objectForKey("name") as NSArray).objectAtIndex(0))

Answer 2

我建议创建一个或多个类并反序列化该JSON，以便更好地访问数据并避免访问时出错。

顺便说一下，通过使数据类型更加明确，它可以工作：

let dict = jsonResult.objectAtIndex(0) as NSDictionary
let array = dict["name"] as NSArray

println(array.objectAtIndex(0))

Answer 3

另一种选择是将jsonResult投射到Array<AnyObject>并使用subscript语法来获取必要的值

let jsonString : String = "[{\"name\":[\"Fred\",\"John\"],\"age\":21},{\"name\":\"Bob\",\"age\":35}]"
let myData:NSData? = jsonString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)
var jsonResult: AnyObject = NSJSONSerialization.JSONObjectWithData(myData!, options: NSJSONReadingOptions.MutableContainers, error: nil);

if let lJsonArray = jsonResult as? Array<AnyObject> {
    println(lJsonArray[0].objectForKey("name")[0])
}

AnyObject？没有名为＆＃39; objectAtIndex＆＃39;的成员

3 个答案: