json - Swift JSONSerialization.jsonObject 错误

Question

我环顾四周，但没有找到解决这个困扰我的错误的答案。我尝试添加一个“as!NSMutableArray”，但这给了我另一个错误。关于如何解决它的任何想法？我将我的项目从 Objective-C 转换为 Swift，所以希望代码一切正常我有 20 多个错误，现在我减少到 3 个错误。谢谢。

错误信息:

'jsonObject' produces 'Any', not the expected contextual result type 'NSMutableArray'

从服务器获取数据的代码

// Retrieving Data from Server
func retrieveData() {

    let getDataURL = "http://ip/example.org/json.php"
    let url: NSURL = NSURL(string: getDataURL)!

    do {

        let data: NSData = try NSData(contentsOf: url as URL)
        jsonArray = JSONSerialization.jsonObject(with: data, options: nil)
    }
    catch {
        print("Error: (data: contentsOf: url)")
    }

    // Setting up dataArray
    var dataArray: NSMutableArray = []

    // Looping through jsonArray
    for i in 0..<jsonArray.count {

        // Create Data Object

        let dID: String = (jsonArray[i] as AnyObject).object(forKey: "id") as! String
        let dName: String = (jsonArray[i] as AnyObject).object(forKey: "dataName") as! String
        let dStatus1: String = (jsonArray[i] as AnyObject).object(forKey: "dataStatus1") as! String
        let dStatus2: String = (jsonArray[i] as AnyObject).object(forKey: "dataStatus2") as! String
        let dURL: String = (jsonArray[i] as AnyObject).object(forKey: "dataURL") as! String

        // Add Data Objects to Data Array
        dataArray.add(Data(dataName: dName, andDataStatus1: dStatus1, andDataStatus2: dStatus2, andDataURL: dURL, andDataID: dID))
    }

    self.myTableView.reloadData()
}

Answer 1

jsonObject 函数将返回一个类型为 Any 的值，但 jsonArray 的类型为 NSMutableArray。如果出现问题，这个函数会抛出一个错误，在它之前放一个 try 关键字。根据我的经验，让我们将 jsonArray 的类型更改为字典数组，这样您就可以轻松提取数据。

    do {
        let data: Data = try Data(contentsOf: url as URL)
        let jsonArray: [[String: AnyObject]] = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as! [[String: AnyObject]]
        print("json: \(jsonArray)")

        for dict in jsonArray {
            let dataName = dict["dataName"] as! String
            print("dataName: \(dataName)")
        }
    }
    catch {
        print("Error: (data: contentsOf: url)")
    }