我使用以下代码创建了一个后台URLSession
对象:
let identifier = /* some background identifier */
let config = URLSessionConfiguration.background(withIdentifier: identifier)
self.session = URLSession(configuration: config, delegate: self, delegateQueue: nil)
我还在委托类中实现了以下URLSessionDataDelegate
方法:
public func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive response: URLResponse, completionHandler: @escaping (URLSession.ResponseDisposition) -> Void) {
// code goes here
}
public func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
// code goes here
}
public func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
// code goes here
}
我可以使用以下内容从此会话成功呼叫URLSessionUploadTask
:
let fileURl = /* some file url */
let request = /* some URLRequest */
let task = session.uploadTask(with: request, fromFile: fileUrl)
task.resume()
但出于某种原因,我只收到回调:
`urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?)`
和
`urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data)`.
委托方法:
`urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive response: URLResponse, completionHandler: @escaping (URLSession.ResponseDisposition) -> Void)`
永远不会被召唤。
这是Xcode8中的错误还是我错过了重要的内容? 谢谢你的帮助!
答案 0 :(得分:3)
Apple SDK直接引用此方法:
/*
* Messages related to the operation of a task that delivers data
* directly to the delegate.
*/
@protocol NSURLSessionDataDelegate <NSURLSessionTaskDelegate>
@optional
/* The task has received a response and no further messages will be
* received until the completion block is called. The disposition
* allows you to cancel a request or to turn a data task into a
* download task. This delegate message is optional - if you do not
* implement it, you can get the response as a property of the task.
*
* This method will not be called for background upload tasks (which cannot be converted to download tasks).
*/
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask
didReceiveResponse:(NSURLResponse *)response
completionHandler:(void (^)(NSURLSessionResponseDisposition disposition))completionHandler;
编辑:为报价添加了更多上下文