Swift - Scaricare video con downloadTaskWithURL

Question

sto download di un video grazie a downloadTaskWithURL e sto salvandolo alla mia galleria con questo codice:

func saveVideoBis(fileStringURL:String){ 

    print("saveVideoBis"); 

    let url = NSURL(string: fileStringURL); 
    (NSURLSession.sharedSession().downloadTaskWithURL(url!) { (location:NSURL?, r:NSURLResponse?, e:NSError?) -> Void in 

     let mgr = NSFileManager.defaultManager() 

     let documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0]; 

     print(documentsPath); 

     let destination = NSURL(string: NSString(format: "%@/%@", documentsPath, url!.lastPathComponent!) as String); 

     print(destination); 

     try? mgr.moveItemAtPath(location!.path!, toPath: destination!.path!) 

     PHPhotoLibrary.requestAuthorization({ (a:PHAuthorizationStatus) -> Void in 
      PHPhotoLibrary.sharedPhotoLibrary().performChanges({ 
       PHAssetChangeRequest.creationRequestForAssetFromVideoAtFileURL(destination!); 
       }) { completed, error in 
        if completed { 
         print(error); 
         print("Video is saved!"); 
         self.sendNotification(); 
        } 
      } 
     }) 
    }).resume() 
} 

Funziona perfettamente bene sul mio simulatore, ma sul mio iPad al il video non viene salvato anche se appare print("Video is saved!");. Hai qualche idea del perché?

Ho anche quel messaggio che appare nella mia console

Unable to create data from file (null)

Answer 1

Si prega di controllare i commenti attraverso il codice:

Xcode 8 • Swift 3

import UIKit 
import Photos 

class ViewController: UIViewController { 

    func downloadVideoLinkAndCreateAsset(_ videoLink: String) { 

     // use guard to make sure you have a valid url 
     guard let videoURL = URL(string: videoLink) else { return } 

     guard let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else { return } 

     // check if the file already exist at the destination folder if you don't want to download it twice 
     if !FileManager.default.fileExists(atPath: documentsDirectoryURL.appendingPathComponent(videoURL.lastPathComponent).path) { 

      // set up your download task 
      URLSession.shared.downloadTask(with: videoURL) { (location, response, error) -> Void in 

       // use guard to unwrap your optional url 
       guard let location = location else { return } 

       // create a deatination url with the server response suggested file name 
       let destinationURL = documentsDirectoryURL.appendingPathComponent(response?.suggestedFilename ?? videoURL.lastPathComponent) 

       do { 

        try FileManager.default.moveItem(at: location, to: destinationURL) 

        PHPhotoLibrary.requestAuthorization({ (authorizationStatus: PHAuthorizationStatus) -> Void in 

         // check if user authorized access photos for your app 
         if authorizationStatus == .authorized { 
          PHPhotoLibrary.shared().performChanges({ 
           PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: destinationURL)}) { completed, error in 
            if completed { 
             print("Video asset created") 
            } else { 
             print(error) 
            } 
          } 
         } 
        }) 

       } catch { print(error) } 

      }.resume() 

     } else { 
      print("File already exists at destination url") 
     } 

    } 

    override func viewDidLoad() { 
     super.viewDidLoad() 
     downloadVideoLinkAndCreateAsset("https://www.yourdomain.com/yourmovie.mp4") 
    } 

}