Question

我已经实现了一个名为RCHDownload

的模型类

它具有使用String开始下载文件的功能，它被称为addDownload(url: String)

使用名为sharedInstance

的单例，可以在任何我想要的地方使用此功能

现在我想做的是在我的UIWebView委托方法

中

func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebViewNavigationType) -> Bool {}

我希望它在开始下载之前检查可能的文件，但到目前为止我无法做到这一点

我尝试使用以下内容进行检查：request.url.isFileURL＆amp; request.url.checkResourceIsReachable()没有运气。有什么建议吗？

Answer 1

我认为我应该为那些不了解如何检查可下载文件的人提供一个明确的答案

以下是：

您可以在某处创建一个包含受支持文件的数组mime Types

lazy var supportedFileTypes = ["audio/mpeg", "audio/aiff", "audio/x-aiff", "video/avi", "video/msvideo", "video/x-msvideo", "application/x-troff-msvideo", "text/plain", "application/octet-stream", "image/gif", "application/vnd.ms-excel", "application/excel", "application/x-excel", "application/xml", "text/xml", "application/zip", "multipart/x-zip", "image/bmp", "image/jpeg", "image/pjpeg", "application/x-compressed", "application/x-gzip", "text/x-h", "audio/x-mpequrl", "application/x-midi", "audio/x-midi", "audio/mpeg3", "audio/x-mpeg-3", "video/mpeg", "video/x-mpeg", "image/png", "application/mspowerpoint", "application/vnd.ms-powerpoint", "application/rtf", "application/x-rtf", "application/plain", "application/x-compressed", "application/gnutar", "audio/wav", "audio/x-wav", "image/tiff", "image/x-tiff", "application/msword", "video/quicktime", "application/x-7z-compressed", "audio/x-aac", "audio/mp4", "video/jpeg", "video/jpm", "video/3gpp", "video/3gpp2", "video/mp4"]

然后在这个UIWebViewDelegate方法中执行此操作

    func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebViewNavigationType) -> Bool {

    let nvc = self.tabBarController?.viewControllers?[1] as! UINavigationController
    let dvc = nvc.viewControllers[0] as! RCHDownloadTVC
    var isDownloadable = false // Bool to check whether the file is downloadable

    // create a session with a http head request 
    let session = URLSession(configuration: URLSessionConfiguration.default())
    var newRequest = URLRequest(url: request.url!)
    newRequest.httpMethod = "HEAD"

    // Start a data task
    let task = session.dataTask(with: newRequest) { (data, response, error) in
        // It is important to use this code on main thread if you have UIAlertController to ask if the user wants to download the file
        DispatchQueue.main.sync(execute: {

            let httpResponse = response as? HTTPURLResponse
            // You check if there is a response - 200 means there is
            if httpResponse?.statusCode == 200 {
                // then you check for the mime type if it is supported by your application
                for (_, mime) in sharedManagerStore.supportedFileTypes.enumerated() {
                    if response?.mimeType == mime {
                        self.showDownloadDecisionAlert(with: { (alert) in
                            sharedDownloadStore.addDownload(with: (request.url?.absoluteString)!)
                            dvc.reloadDownloadController()
                            self.webView.mediaPlaybackRequiresUserAction = true
                            self.webView.allowsInlineMediaPlayback = false
                            self.webView.goBack()
                            isDownloadable = true
                            }, completionHandlerTwo: { (alert) in
                                self.webView.mediaPlaybackRequiresUserAction = false
                                self.webView.allowsInlineMediaPlayback = true
                                isDownloadable = false
                        })
                        break
                    }
                }
            }
        })
    }

    task.resume()

    if isDownloadable != true {
        // You return true if the file is not downloadable
        return true
    } else {
        // You return false if the file is downloadable
        return false
    }
}

如何检查UIWebView url链接以查找可能的文件？

1 个答案: