“通话中的额外参数”我有这个错误....这个代码有什么问题

Question

这个代码有什么问题？我试图从我的SQL数据库中检索数据。

import Foundation 

class Service { 
    var settings:Settings! 

    init(){ 
     self.settings = Settings() 
    } 

    func getContacts (callback:(NSDictionary)->()){ 
     request(settings.viewContacts, callback: callback) 
    } 

    func request(url: String , callback:(NSDictionary) ->()) { 
     let nsURL = NSURL(string : url) 

     let task = NSURLSession.sharedSession().dataTaskWithURL(nsURL!){ 
      (data , reponse , error) in 
      let error: NSError? 

      var reponse = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers , error) as NSDictionary // extra argument in call , i am having this error. 
      callback(reponse) 
     } 
     task.resume() 
    } 
} 

Answer 1

实际上Swift2没有NSError上NSJSONSerialization

你需要用它在一个do/catch块，因为这是报告错误，而不是使用NSError的首选方式：

do { 
    let reponse = try NSJSONSerialization.JSONObjectWithData(data!, options:NSJSONReadingOptions.MutableContainers) as! NSDictionary 
    // use reponse 
    callback(reponse) 
} catch { 
    // report error 
} 

如果您需要NSError对象属性，请使用：

do { 
    let reponse = try NSJSONSerialization.JSONObjectWithData(data!, options:NSJSONReadingOptions.MutableContainers) as! NSDictionary 

    // use reponse 
    callback(reponse) 
} catch let error as NSError { 
    print("json error: \(error.localizedDescription)") 
}