Question

我是新手，无法从url打开pdf文件

我的代码就是这样

 @IBOutlet var webview: WKWebView!


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.

        webview.navigationDelegate = self

        let url = URL(string: "http://www.orimi.com/pdf-test.pdf")
        self.webview.load(URLRequest(url: url!))

    }

    func webView(_ webView: WKWebView, didCommit navigation: WKNavigation!) {
        print("Start loading")
    }

    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        print("End loading")
    }

我正在使用此代码，我可以打开URL链接和图像，但不能打开pdf文件

Answer 1

您正在尝试将http-Url加载到WebView中，这在iOS中是默认禁止的。您可以使用https-Url尝试相同的代码，也可以在Info.plist中更改传输安全设置以允许任意加载

另一个有用的想法可能是使用SFSafariViewController从另一个URL显示网站或文档。

Answer 2

尝试下面的代码，让我知道

 @IBOutlet weak var webView: WKWebView!


override func viewWillAppear(_ animated: Bool) {

        super.viewWillAppear(true)
        self.initialSetup()
    }

    private func initialSetup () {
        webView.navigationDelegate = self
        self.loadHTMLStringImage()

    }

    private func loadHTMLStringImage() -> Void {
            let htmlString = "<p>Identify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the imagesIdentify the arrow-marked structures in the images</p>"
            webView.loadHTMLString(htmlString, baseURL: nil)
        }

Answer 3

如果您使用> = iOS 11，则可以使用苹果PDFKit。这里是例子。

import PDFKit


class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()

        let pdfView = PDFView(frame: view.bounds)
        view.addSubview(pdfView)

        if let url = URL(string: link_of_pdf), let document = PDFDocument(url: url) {
            pdfView.document = document
        }
    }
}

但是，如果您需要低于iOS 11的支持，则可以使用CGPDFDocument（但是您需要为此工作很多），或者找到第三方lib。

Answer 4

为什么使用WKWebView是因为可以使用最常见的方法，即使用UIDocumentInteractionController和UIAlertController

检查这部分使用带有进度视图的流行Alamofire的代码部分（您可以使用任何喜欢的库来实现类似功能，当然也可以使用URLSession）。

请注意，如果您在控制器中使用它，则它必须实现委托UIDocumentInteractionControllerDelegate。

这是带有下载功能和进度条的完整源代码：

class MyController: UIViewController, UIDocumentInteractionControllerDelegate {

        var progressView: UIProgressView?    

        override func viewDidLoad() {
            super.viewDidLoad()
        }               

        func downloadCommentFile(id: Int) {
            let destination = DownloadRequest.suggestedDownloadDestination(for: .documentDirectory)  

            //MARK: Progress controller
            let alertView = UIAlertController(title: "Downloading", message: "Downloading file", preferredStyle: .alert)
            alertView.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))

            //  Show UIAlertController it to your users
            present(alertView, animated: true, completion: {
                //  Add your progressbar after alert is shown (and measured)
                let margin:CGFloat = 8.0
                let rect = CGRect(x: margin, y: 72.0, width: alertView.view.frame.width - margin * 2.0 , height: 10.0)
                self.progressView = UIProgressView(frame: rect)
                self.progressView!.progress = 0
                self.progressView!.tintColor = self.view.tintColor
                alertView.view.addSubview(self.progressView!)
            })

            let url = "http://MyUrl/DownloadFile"
            let headers = ["Header1": "header 1 value"]

            Alamofire.download(url,
                method: .post,
                parameters: ["id": id],
                encoding: JSONEncoding.default,
                headers: headers,
                to: destination).downloadProgress(closure: { (progress) in
                    //progress closure                  
                    self.progressView?.setProgress(Float(progress.fractionCompleted), animated: true)
                }).response(completionHandler: { (DefaultDownloadResponse) in
                    //here you able to access the DefaultDownloadResponse
                    //result closure
                    alertView.dismiss(animated: true, completion: {
                        let viewer = UIDocumentInteractionController(url: DefaultDownloadResponse.destinationURL!)
                        viewer.delegate = self
                        viewer.presentPreview(animated: true)
                })
            })      
        }

        func documentInteractionControllerViewControllerForPreview(_ controller: UIDocumentInteractionController) -> UIViewController {
            return self
        }

        private func documentInteractionControllerViewForPreview(controller: UIDocumentInteractionController!) -> UIView! {
            return self.view
        }

        func documentInteractionControllerRectForPreview(_ controller: UIDocumentInteractionController) -> CGRect {
            return self.view.frame
        }
    }

Answer 5

如果要在WKWebView中加载pdf文件，可以使用以下代码：-

import UIKit
import WebKit

class WebViewController: UIViewController {

    @IBOutlet weak var webView: WKWebView! {
        didSet {
            webView.navigationDelegate = self
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        loadWebView()
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(true)
        hideLoader()
    }

    private func loadWebView() {
        showLoader()
        let request = URLRequest(url: URL(string: "http://www.orimi.com/pdf-test.pdf)!)
        DispatchQueue.main.async {
            self.webView.load(request)
        }
    }

    private func showLoader() {
        DispatchQueue.main.async {
            //show your loader
        }
    }

    private func hideLoader() {
        DispatchQueue.main.async {
            //hide your loader
        }
    }

}

extension WebViewController: WKNavigationDelegate {

    func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) {
        hideLoader()
        showAlert(error.localizedDescription)
    }

    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        hideLoader()
    }

}

如何直接从URL快速打开pdf文件

5 个答案: