当前位置: 动力学知识库 > 问答 > 编程问答 >

ios - How to link Firebase download file with a progress view?

问题描述:

Below is the code I am using to download PDF files from Firebase storage.

What I want to do is to link it with a download progress view with percentage instead of activity indicator.

import Foundation

import UIKit

import Firebase

import SwiftLoader

class showPdfVC: UIViewController , UIWebViewDelegate,ReaderViewControllerDelegate{

var pdfbooks = UIWebView()

var nIndex:NSInteger!

var post: Post!

var db : DBHelper = DBHelper()

var book : BookModel?

@IBAction func backbtn(_ sender: Any) {

if let navController = self.navigationController {

navController.popViewController(animated: true)

}

}

override func viewDidLoad() {

super.viewDidLoad()

var config : SwiftLoader.Config = SwiftLoader.Config()

config.size = 150

config.spinnerColor = .brown

config.foregroundColor = .black

config.foregroundAlpha = 0.5

config.titleTextColor = .brown

SwiftLoader.setConfig(config)

if "" != book?.bookPath {

// self.activityIND.isHidden = true

// self.activityIND.stopAnimating()

UIApplication.shared.isNetworkActivityIndicatorVisible = false

SwiftLoader.hide()

loadReader(filePaht: (book?.bookPath)!)

} else {

let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]

let strName = book?.id

let filePath = "\(documentsPath)/"+strName!+".pdf"

let fileManager = FileManager.default

// self.activityIND.startAnimating()

SwiftLoader.show(title: "Loading...", animated: true)

UIApplication.shared.isNetworkActivityIndicatorVisible = true

if fileManager.fileExists(atPath: filePath) {

// self.loadFromUrl(path: filePath)

loadReader(filePaht: (book?.bookPath)!)

return;

}

let reference = FIRStorage.storage().reference(forURL: (self.book?.bookURL)!)

reference.data(withMaxSize: 50 * 1024 * 1024) { (data, error) -> Void in

if (error != nil) {

print ("unable to download pdf file from Firebase Storage")

// self.activityIND.isHidden = false

// self.activityIND.startAnimating()

SwiftLoader.show(title: "Loading...", animated: true)

UIApplication.shared.isNetworkActivityIndicatorVisible = true

} else {

if ((try! data?.write(to: URL.init(fileURLWithPath: filePath, isDirectory: false))) != nil) {

// self.loadFromUrl(path: filePath)

print ("pdf file is downloaded from Firebase Storage")

self.db.upDate(id: (self.book?.id)!, bookPath: filePath)

// self.activityIND.isHidden = true

SwiftLoader.hide()

self.loadReader(filePaht: filePath)

UIApplication.shared.isNetworkActivityIndicatorVisible = false

}

}

}

}

}

func loadReader(filePaht : String) {

let document = ReaderDocument(filePath: filePaht, password: nil)

if document != nil {

let readerVC = ReaderViewController(readerDocument: document)

readerVC?.delegate = self

readerVC?.modalTransitionStyle = UIModalTransitionStyle.crossDissolve

readerVC?.modalPresentationStyle = UIModalPresentationStyle.fullScreen

self.navigationController?.pushViewController(readerVC!, animated: true)

}

}

func dismiss(_ viewController: ReaderViewController!) {

_ = self.navigationController?.popToRootViewController(animated: true)

}

override func didReceiveMemoryWarning() {

super.didReceiveMemoryWarning()

}

}

网友答案:

Several thoughts:

  • Don't download in memory and then write to disk--we have a method that downloads straight to the file system
  • Attach listeners rather than a single completion handler--that way you can listen to progress updates
  • Use something like MBProgressHUD to show an incremental progress bar
  • No need to set the isNetworkActivityIndicatorVisible as we'll do that for you

Putting that together, you get something like:

// Create a reference to the file we want to download
let starsRef = storageRef.child("images/stars.jpg")

// Start the download (in this case writing to a file)
let downloadTask = storageRef.write(toFile: localURL)

// Start progress indicator

// Observe changes in status
downloadTask.observe(.progress) { snapshot in
  // Download reported progress
  let percentComplete = 100.0 * Double(snapshot.progress!.completedUnitCount)
    / Double(snapshot.progress!.totalUnitCount)
  // Update the progress indicator
}

downloadTask.observe(.success) { snapshot in
  // Download completed successfully
  // Stop progress indicator
}

// Errors only occur in the "Failure" case
downloadTask.observe(.failure) { snapshot in
  // An error occurred!
  // Stop progress indicator
}
分享给朋友:
您可能感兴趣的文章:
随机阅读: