从变量中的statusCode返回NSHTTPURLResponse

Question

我正在尝试返回变量statusCode，它应该接受NSHTTPURLResponse的statusCode属性的值，但是我得到零，即使当我检查时，我看到数据已经成功地发布了。它返回我用.初始化变量的0。我该怎么做？谢谢。

var statusCode = 0

let queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
dispatch_async(queue) {
      let request = NSMutableURLRequest(URL: NSURL(string: escapedUrl!)!)
      request.HTTPMethod = "POST"
      let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
          data, response, error in

          if error != nil {
              statusCode = 0
          } else if let httpResponse = response as? NSHTTPURLResponse {
              if httpResponse.statusCode == 200 {
                  statusCode = httpResponse.statusCode
              } else {
                  statusCode = 0
              }
          }
      }
      task.resume()
  }
  return statusCode

}

Answer 1

在异步调用返回结果之前返回statusCode。您可以通过传递一个闭包并在web服务返回结果时调用它来处理这种情况。对于该方法，实现如下所示：

func postData(escapedUrl : String?, onCompletion:(Int)->Void)
{
    let queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
    dispatch_async(queue)
    {
        let request = NSMutableURLRequest(URL: NSURL(string: escapedUrl!)!)
        request.HTTPMethod = "POST"
        let task = NSURLSession.sharedSession().dataTaskWithRequest(request) 
        {
            data, response, error in

            var statusCode = 0

            if error != nil
            {
                statusCode = 0
            }
            else if let httpResponse = response as? NSHTTPURLResponse
            {
                if httpResponse.statusCode == 200
                {
                    statusCode = httpResponse.statusCode
                }
                else
                {
                    statusCode = 0
                }
            }
            // Passing back the result
            onCompletion(statusCode);
        }
        task.resume()
    }
}

您可以像这样调用该方法：

postData("yourURLString") { (statusCode) -> Void in
    // Check status code here
}