Swift 3 URLSession.shared（）对成员'dataTask的歧义引用（with：completionHandler :)错误（bug）

问题描述：

你好我有工作json解析代码为swift2.2，但是当我用它为Swift 3.0给我那个错误Swift 3 URLSession.shared（）对成员'dataTask的歧义引用（with：completionHandler :)错误（bug）

ViewController.swift：132：31：暧昧参考成员 'dataTask（附：completionHandler :)'

我的代码在这里

let listUrlString = "http://bla.com?batchSize=" + String(batchSize) + "&fromIndex=" + String(fromIndex) 
    let myUrl = URL(string: listUrlString); 
    let request = NSMutableURLRequest(url:myUrl!); 
    request.httpMethod = "GET"; 

    let task = URLSession.shared().dataTask(with: request) { 
     data, response, error in 

     if error != nil { 
      print(error!.localizedDescription) 
      DispatchQueue.main.sync(execute: { 
       AWLoader.hide() 
      }) 

      return 
     } 

     do { 

      let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? NSArray 

      if let parseJSON = json { 

       var items = self.categoryList 

       items.append(contentsOf: parseJSON as! [String]) 

       if self.fromIndex < items.count { 

        self.categoryList = items 
        self.fromIndex = items.count 

        DispatchQueue.main.async(execute: { 

         self.categoriesTableView.reloadData() 

         AWLoader.hide() 

        }) 
       }else if(self.fromIndex == items.count){ 


        DispatchQueue.main.async(execute: { 

         AWLoader.hide() 

        }) 

       } 



      } 

     } catch { 
      AWLoader.hide() 
      print(error) 

     } 
    } 

    task.resume()

感谢的想法。

我得到相同的错误，因为我传递一个字符串到'dataTask（带有：'例如我有'url =“www.yahoo.com'，我直接将它传递给函数**而没有**将其转换为'URL' – Honey

答

编译器被函数签名弄糊涂了。你能解决这个问题是这样的：

let task = URLSession.shared.dataTask(with: request as URLRequest) {

但是，请注意，我们没有投“请求”为URLRequest在此签名如果它被宣布作为较早而不是URLRequest的NSMutableURLRequest：

这是NSMutableURLRequest和新的URLRequest之间的自动投射失败，这迫使我们在这里进行投射。

谢谢你的工作，我认为会帮助很多人 – SwiftDeveloper

var request = URLRequest（url：myUrl！）' –

[SE-0072]（https://github.com/apple/swift-evolution/blob/master/proposals/0072-eliminate-implicit-bridging-conversions.md）说，删除隐式桥接当“swifty函数名称”变成“事实上的覆盖方法”时，我们不能反向查找Objective-C SEL，所以我们必须使用或者强制转换为基础struct。 – quesera2

答

你init'd myRequest为NSMutableURLRequest，你需要这样的：

var URLRequest

斯威夫特开沟两个NSMutable...事情。只需使用var即可获得新课程。

由于一吨的人。这是完美的解决方案。干杯！ – Blisskarthik

答

经过测试的xcode 8稳定版本;需要使用var request变量，URLRequest()随着这就是你可以很容易地解决这个问题（错误）

var request = URLRequest(url:myUrl!)而

let task = URLSession.shared().dataTask(with: request as URLRequest) { }

工作得很好！谢谢你们，我想帮助很多人。！

这是没有意义的，从铸的URLRequest到的URLRequest –

'变种请求=的URLRequest（URL：URL）; 令任务= URLSession.shared（）dataTask（具有：请求）。{...}'' –

shared'是一个属性，而不是在夫特3的功能（无括号内）。 – vadian

答

此问题是由URLSession引起具有两个dataTask方法

open func dataTask(with request: URLRequest, completionHandler: @escaping (Data?, URLResponse?, Error?) -> Swift.Void) -> URLSessionDataTask 
open func dataTask(with url: URL, completionHandler: @escaping (Data?, URLResponse?, Error?) -> Swift.Void) -> URLSessionDataTask

的第一个具有URLRequest作为参数，而第二个具有URL作为参数，所以我们需要指定要调用哪个类型，例如，我想呼叫的第二方法

let task = URLSession.shared.dataTask(with: url! as URL) { 
    data, response, error in 
    // Handler 
}

没有任何意义。谢谢 – iBug

答

的Xcode 8和夫特3。0

使用URLSession：

let url = URL(string:"Download URL")! 
let req = NSMutableURLRequest(url:url) 
let config = URLSessionConfiguration.default 
let session = URLSession(configuration: config, delegate: self, delegateQueue: OperationQueue.main) 

let task : URLSessionDownloadTask = session.downloadTask(with: req as URLRequest) 
task.resume()

URLSession代表电话：

func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) { 

} 


func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, 
didWriteData bytesWritten: Int64, totalBytesWritten writ: Int64, totalBytesExpectedToWrite exp: Int64) { 
        print("downloaded \(100*writ/exp)" as AnyObject) 

} 

func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL){ 

}

使用块GET/POST/PUT/DELETE：

let request = NSMutableURLRequest(url: URL(string: "Your API URL here" ,param: param))!, 
     cachePolicy: .useProtocolCachePolicy, 
     timeoutInterval:"Your request timeout time in Seconds") 
    request.httpMethod = "GET" 
    request.allHTTPHeaderFields = headers as? [String : String] 

    let session = URLSession.shared 

    let dataTask = session.dataTask(with: request as URLRequest) {data,response,error in 
     let httpResponse = response as? HTTPURLResponse 

     if (error != nil) { 
     print(error) 
     } else { 
     print(httpResponse) 
     } 

     DispatchQueue.main.async { 
      //Update your UI here 
     } 

    } 
    dataTask.resume()

工作对我罚款..尝试它100％的结果保证

答

// prepare json data 
     let mapDict = [ "1":"First", "2":"Second"] 

     let json = [ "title":"ABC" , "dict": mapDict ] as [String : Any] 
     let jsonData : NSData = NSKeyedArchiver.archivedData(withRootObject: json) as NSData 

     // create post request 
     let url = NSURL(string: "http://httpbin.org/post")! 
     let request = NSMutableURLRequest(url: url as URL) 
     request.httpMethod = "POST" 

     // insert json data to the request 
     request.httpBody = jsonData as Data 


     let task = URLSession.shared.dataTask(with: request as URLRequest){ data,response,error in 
      if error != nil{ 
       return 
      } 
      do { 
       let result = try JSONSerialization.jsonObject(with: data!, options: []) as? [String:AnyObject] 

       print("Result",result!) 

      } catch { 
       print("Error -> \(error)") 
      } 
     } 

     task.resume()

答

要通过GET请求加载数据，你不需要任何URLRequest（没有分号）

let listUrlString = "http://bla.com?batchSize=" + String(batchSize) + "&fromIndex=" + String(fromIndex) 
let myUrl = URL(string: listUrlString)! 
let task = URLSession.shared.dataTask(with: myUrl) { ...

答

对我来说，我做的这个发现，

let url = URL(string: urlString) 
URLSession.shared.dataTask(with: url!) { (data, response, error) in ...}

不能使用

"let url = NSURL(string: urlString)

答

对于斯威夫特3和Xcode中8：

 var dataTask: URLSessionDataTask? 

     if let url = URL(string: urlString) { 
      self.dataTask = URLSession.shared.dataTask(with: url, completionHandler: { (data, response, error) in 

       if let error = error { 
        print(error.localizedDescription) 
       } else if let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode == 200 { 
        // You can use data received. 
        self.process(data: data as Data?) 
       } 
      }) 
     } 
    }

//注意：您可以随时使用调试器来检查错误

答

在SWIFT 3编译器是由函数签名混淆。指定它将清除错误。同时将url字符串转换为URL类型。以下代码适用于我。

let urlString = "http://bla.com?batchSize=" 
    let pathURL = URL(string: urlString)! 
    var urlRequest = URLRequest(url:pathURL) 

    let session = URLSession.shared 
    let dataTask = session.dataTask(with: urlRequest as URLRequest) { (data,response,error) in

答

let task = URLSession.shared.dataTask(with: request as URLRequest, completionHandler: { data,response,error in 
     if error != nil{ 
      print(error!.localizedDescription) 
      return 
     } 
     if let responseJSON = (try? JSONSerialization.jsonObject(with: data!, options: [])) as? [String:AnyObject]{ 
      if let response_token:String = responseJSON["token"] as? String { 
       print("Singleton Firebase Token : \(response_token)") 
       completion(response_token) 
      } 
     } 
    }) 
    task.resume()

答

简短的答案斯威夫特3：

guard let requestUrl = URL(string: yourURL) else { return } 

let request = URLRequest(url:requestUrl) 
URLSession.shared.dataTask(with: request) { 
    (data, response, error) in 
    ... 

}.resume()

答

在我的情况下误差在NSURL

let url = NSURL(string: urlString)

在斯威夫特3，你必须写只是网址：

let url = URL(string: urlString)

Swift 3 URLSession.shared（）对成员'dataTask的歧义引用（with：completionHandler :)错误（bug）

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