Swift 3 ios 10 Xcode 8 在设备之间保存和加载 pdf

Question

（这是我在这里的第一篇文章，对于我所犯的任何错误，我深表歉意） 我有在 iOS 模拟器上完美运行的代码，但是一旦我在真实设备上运行它，它就会在线显示白屏并出现此错误：com.apple.WebKit.WebContent：113：找不到指定的服务

这是我将 pdf 文件从 firebase 下载到设备的代码：

@IBAction func downloadButtonPressed (sender: UIButton) {


        print("zzz download button pressed")

        let directoryPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true) //FileManager().url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
        if directoryPath.count > 0 {
            let documentsDirectory = directoryPath[0]
            let pathURL = URL(fileURLWithPath: documentsDirectory)
            let fileURL = pathURL.appendingPathComponent("\(fixture.id).pdf")

            let httpsReference = FIRStorage.storage().reference(forURL: fixture.onlineManual)
            print("zzz urlManual: \(fixture.onlineManual)")


            let downloadTask = httpsReference.write(toFile: fileURL) {(URL, error) in
                if error != nil {
                    print("downloadError with pdf")
                    print(error?.localizedDescription)
                } else {
                    print("zzz donwload successful: \(URL!)")
                    let appDelegate = UIApplication.shared.delegate as! AppDelegate
                    let context = appDelegate.persistentContainer.viewContext
                    let newManual = NSEntityDescription.insertNewObject(forEntityName: "OfflineManuals", into: context)
                    newManual.setValue(self.fixture.id, forKey: "id")
                    newManual.setValue("\(URL!)", forKey: "manual")
                    do {

                        try context.save()
                        print("zzz manual saved to device")

                    } catch {

                        print("zzz error saving manual to core data")
                    }
                }
            }
        }
    }

这是从设备加载文件并将其显示在 WKWebView 中的代码

func loadRequest() {


        let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
        if documentsPath.count > 0 {

            let documentsDirectory = documentsPath[0]
            let restorePath = documentsDirectory + "/\(manualURL!).pdf"
            let url = URL(fileURLWithPath: restorePath)
            print("zzz url for local file: \(url)")
            let req = URLRequest(url: url)
            webView.load(req)
        }
    }

感谢您的阅读！

Answer 1

我终于找到了一种方法来做到这一点。我仍然不知道为什么我在问题中的代码不能在真实设备上运行，但这个可以，因为我发现很多有类似问题的人拼命寻找答案，所以使用这个：

SWIFT3 XCODE 8 IOS 10

import UIKit
import WebKit

class ViewController: UIViewController {

@IBOutlet weak var myView: UIView!
var webView: WKWebView!
let sema = DispatchSemaphore( value: 0 )


override func viewDidLoad() {
    super.viewDidLoad()

    webView = WKWebView()


    myView.addSubview(webView)
    savePDFtoDevice()
    loadPDF()


}

不需要 LayoutSubviews，但没有它我会遇到问题...

override func viewDidLayoutSubviews() {
    print("zzz width: \(self.myView.frame.size.width), height: \(myView.frame.size.height)")
    print("zzz width screen: \(self.view.frame.width)")
    let frame = CGRect(x: 30.0, y: 30.0, width: (self.myView.frame.width - 60), height: 300)
    webView.frame = frame
}

func savePDFtoDevice(){
    let myURL = URL(string: "http://www.claypaky.it/media/documents/HR_Mythos_Manual_05.2016_EN.pdf")
    let req = URLRequest(url: myURL!)
    let session = URLSession(configuration: .default)
    session.dataTask(with: req) { (data, response, error) in
        if error != nil {
            print("zzz error got no session")
        } else {
            if let pdfData = data {
                var url = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
                url = url.appendingPathComponent("file.pdf")
                print("zzz url to save: \(url)")
                print("zzz got data: \(pdfData.description)")
                try? data?.write(to: url)
                print("zzz wrote to file")
                self.sema.signal()

            }

        }
    }.resume()
    sema.wait()
}

func loadPDF() {
    let url = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
    print("zzz url to load from: \(url)")

    do {
        let content =  try FileManager.default.contentsOfDirectory(at: url, includingPropertiesForKeys: nil, options: .skipsHiddenFiles)[0]
        print("zzz file: \(content)")
        webView.loadFileURL(content, allowingReadAccessTo: content)
        print("zzz webView loaded")
    } catch {
        print("zzz error with getting the contents...")
    }
}

}

我在我的应用程序中尝试了更改 URL 和文件名等，它成功了。 终于！！！！