4

我正在尝试将 NSProgress 与 AFNetworking 一起使用，这是我正在使用的代码

//func upload...
//...
let request: NSMutableURLRequest = AFHTTPRequestSerializer().multipartFormRequestWithMethod("POST", URLString: url, parameters: s3parameters, constructingBodyWithBlock: { formData in
      let data: AFMultipartFormData = formData
      data.appendPartWithFileURL(fileURL, name: "file", error: nil)
    }, error: nil)
    request.setValue("application/json", forHTTPHeaderField: "Accept")

    let sessionManager: AFURLSessionManager = AFURLSessionManager(sessionConfiguration: NSURLSessionConfiguration.defaultSessionConfiguration())
    var progress: NSProgress?

    let uploadTask: NSURLSessionUploadTask = sessionManager.uploadTaskWithStreamedRequest(request, progress: &progress, completionHandler: { (response, responseObject, error) in
    //...
    })

    uploadTask.resume()
    progress?.addObserver(self, forKeyPath: "fractionCompleted", options: NSKeyValueObservingOptions.Initial, context: nil)
//...

override func observeValueForKeyPath(keyPath: String, ofObject object: AnyObject, change: [NSObject : AnyObject], context: UnsafeMutablePointer<Void>) {
  let progress: NSProgress = object as NSProgress
  println("progress: \(progress.fractionCompleted)")
}

该文件已正确上传，但事实并非如此 - 我只打印一次进度值（“进度：0.0”），然后我在 AFURLSessionManager.m 中以 EXC_BAD_ACCESS 结束：

#pragma mark - NSURLSessionTaskDelegate

- (void)URLSession:(__unused NSURLSession *)session
          task:(__unused NSURLSessionTask *)task
didSendBodyData:(__unused int64_t)bytesSent
totalBytesSent:(int64_t)totalBytesSent
totalBytesExpectedToSend:(int64_t)totalBytesExpectedToSend
{
    self.progress.totalUnitCount = totalBytesExpectedToSend; <<< EXC_BAD_ACCESS
    self.progress.completedUnitCount = totalBytesSent;
}

我究竟做错了什么？我应该设置“var progress：NSProgress”吗？不同还是我还缺少其他东西？

4

1 回答 1

1

哦，我已经修好了 - 我需要从进度中删除观察者：

let uploadTask: NSURLSessionUploadTask = sessionManager.uploadTaskWithStreamedRequest(request, progress: &progress, completionHandler: { (response, responseObject, error) in
//...
progress?.removeObserver(self, forKeyPath: "fractionCompleted", context: nil) // added this line
//...
})
于 2015-01-21T09:55:29.447 回答