ios - 请求超时 NSURLSession

Question

你好，我使用下面的代码向服务器发送请求。如何在此函数中添加超时

static func postToServer(url:String,var params:Dictionary<String,NSObject>, completionHandler: (NSDictionary?, String?) -> Void ) -> NSURLSessionTask {


        let request = NSMutableURLRequest(URL: NSURL(string: url)!)


        let session = NSURLSession.sharedSession()

        request.HTTPMethod = "POST"

    if(params["data"] != "get"){
        do {

            let data = try NSJSONSerialization.dataWithJSONObject(params, options: .PrettyPrinted)

            let dataString = NSString(data: data, encoding: NSUTF8StringEncoding)!
            print("dataString is  \(dataString)")

            request.HTTPBody = data


        } catch {
            //handle error. Probably return or mark function as throws
            print("error is \(error)")
            //return
        }

    }
        request.addValue("application/json", forHTTPHeaderField: "Content-Type")
        request.addValue("application/json", forHTTPHeaderField: "Accept")

        let task = session.dataTaskWithRequest(request) {data, response, error -> Void in
            // handle error

            guard error == nil else { return }
            request.timeoutInterval = 10


           print("Response: \(response)")
            let strData = NSString(data: data!, encoding: NSUTF8StringEncoding)
             completionHandler(nil,"Body: \(strData!)")
          //print("Body: \(strData!)")

            let json: NSDictionary?
            do {
                json = try NSJSONSerialization.JSONObjectWithData(data!, options: .MutableLeaves) as? NSDictionary
            } catch let dataError {
                // Did the JSONObjectWithData constructor return an error? If so, log the error to the console
                print(dataError)
                let jsonStr = NSString(data: data!, encoding: NSUTF8StringEncoding)
              print("Error could not parse JSON: '\(jsonStr)'")
                completionHandler(nil,"Body: \(jsonStr!)")

                // return or throw?
                return
            }


            // The JSONObjectWithData constructor didn't return an error. But, we should still
            // check and make sure that json has a value using optional binding.
            if let parseJSON = json {
                // Okay, the parsedJSON is here, let's get the value for 'success' out of it

                completionHandler(parseJSON,nil)
                //let success = parseJSON["success"] as? Int
                //print("Succes: \(success)")
            }
            else {
                // Woa, okay the json object was nil, something went worng. Maybe the server isn't running?
                let jsonStr = NSString(data: data!, encoding: NSUTF8StringEncoding)
                print("Errors could not parse JSON: \(jsonStr)")
                completionHandler(nil,"Body: \(jsonStr!)")
            }

        }

        task.resume()
        return task
    }

我也做了一些搜索，我开始知道使用这个功能

let request = NSURLRequest(URL: url!, cachePolicy: .ReloadIgnoringLocalAndRemoteCacheData, timeoutInterval: 5.0)

而不是这个

let request = NSMutableURLRequest(URL: NSURL(string: url)!)

但问题是如果我使用上面的函数那么我就不能设置这些变量

request.HTTPBody = data
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
        request.addValue("application/json", forHTTPHeaderField: "Accept")

请有人建议我如何在我的函数中添加超时的正确解决方案

Answer 1

您不能修改您的请求，因为出于某种原因您使用了不可变选项。由于 NSMutableURLRequest 是 NSURLRequest 的子类，您可以使用完全相同的初始化程序 init(URL:cachePolicy:timeoutInterval:) 来创建一个可变实例并设置默认超时。然后根据需要配置(改变)这个请求。

let request = NSMutableURLRequest(URL: url!, cachePolicy: .ReloadIgnoringLocalAndRemoteCacheData, timeoutInterval: 5.0)