json - 在 Swift 中转换 JSON 数据

Question

我从服务器获取一些 JSON 数据，并将其解析为字典。现在我想从字典中获取数据并将其转换为不同的类型，但出现了一些错误。

我试过了

let manager = AFHTTPRequestOperationManager()
manager.requestSerializer = AFJSONRequestSerializer()
manager.GET(
    "http://localhost/example/jsonpage",
    parameters: nil,
    success: { (operation: AFHTTPRequestOperation!,
        responseObject: AnyObject!) in

        if let data = responseObject as? Dictionary<String, AnyObject> {
            let id = data["id"] as? Int
            let persons = data["persons"] as? Dictionary<String, AnyObject>
        }


    },
    failure: { (operation: AFHTTPRequestOperation!,
        error: NSError!) in
        println("Error: " + error.localizedDescription)
    }
)

这些给了我一个错误:

let id = data["id"] as? Int
let persons = data["persons"] as? Dictionary<String, AnyObject>

错误:找不到接受所提供参数的“下标”重载

Answer 1

responseObject类型为NSDictionary，支持的JSON值类型为NSDictionary、NSArray、NSString、NSNumber。转换为字典不会将其值转换为正确的类型。您必须单独转换值。

if let nsid: NSNumber = data["id"] as? NSNumber {
    var id = Int(nsid)
}