Swift dataTaskWithRequest 完成块未执行

Question

我有一个功能，当出现错误时，post 将字典返回给服务器，return 状态代码或错误内容。它有时工作正常，而其余时间跳过完成部分。

func postData(url: String, query: NSDictionary) ->NSObject? {
   var error: NSError?
   var result: NSObject? = nil

   let dest = NSURL("http://myUrl.com")
   let request = NSMutableURLRequest(URL: dest!)
   request.HTTPMethod = "POST"
   request.HTTPBody = NSJSONSerialization.dataWithJSONObject(query, options: NSJSONWritingOptions.allZeros, error: &err)
   request.addValue("application/json", forHTTPHeaderField: "Content-Type")
   request.addValue("application/json", forHTTPHeaderField: "Accept")

   let task = NSURLSession.sharedSession().dataTaskWithRequest(request){
              data, response, error in
              if(error != nil){
                   println(error)
                   result = error 
                   return
              }
              result = (response as! NSHTTPURLResponse).statusCode
              return
    }
    task.resume()
    return result
}

参考了NSURLSession dataTaskWithRequest not being called，知道可能是执行时滞导致的。但是，由于我需要状态代码（到目前为止 return 为零）来确定 post 之后要执行的操作，我想知道如何解决这个问题？

Answer 1

你的方法是异步方法，你不能从中得到return。

您可以传入一个块来处理您的操作 return

func postData(url: String, query: NSDictionary,finished:(NSObject)->()) {
var error: NSError?
var result: NSObject? = nil

let dest = NSURL("http://myUrl.com")
let request = NSMutableURLRequest(URL: dest!)
request.HTTPMethod = "POST"
request.HTTPBody = NSJSONSerialization.dataWithJSONObject(query, options: NSJSONWritingOptions.allZeros, error: &err)
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")

let task = NSURLSession.sharedSession().dataTaskWithRequest(request){
    data, response, error in
    if(error != nil){
        println(error)
        result = error
        return
    }
    finished((response as! NSHTTPURLResponse).statusCode)
}
task.resume()
}

那就用吧

postData(url, dic) { (object:NSObject) -> () in{
//use here
}

Swift dataTaskWithRequest 完成块未执行

Swift dataTaskWithRequest completion block not executed

swift

http-post

nsurlsession