打开并查看文档文件URL

Question

如何使用QLPreviewController打开并查看从Web服务获取的文档文件的URL。

Answer 1

你不能这样做。文档可以很好地解释这一点，但是，您想尝试制作自己的查看器。祝你好运！

参见：

Oficial topic IOS

您可以作为网站显示：“创建和配置文档交互控制器”

- (UIDocumentInteractionController *) setupControllerWithURL: (NSURL) fileURL 
usingDelegate: (id <UIDocumentInteractionControllerDelegate>) interactionDelegate { 

UIDocumentInteractionController *interactionController = 
    [UIDocumentInteractionController interactionControllerWithURL: fileURL]; 
interactionController.delegate = interactionDelegate; 

return interactionController;} 

“一旦你有一个文档交互控制器，你可以使用其属性获取关于相关文件的信息，包括其名称，类型和URL。“

Answer 2

1. 显示某种进度微调。
2. 使用URLSession和URLSessionDownloadTask将文件下载到您的~/documents文件夹。
3. 隐藏进度微调器。
4. 然后，您需要创建一个实现QLPreviewControllerDataSource并保存文档的类的实例。

5. 隐藏进度微调和现在QLPreviewController

   import UIKit 
   import QuickLook 
   
   
   class Document: NSObject, QLPreviewItem { 
       var previewItemURL: URL? 
   } 
   
   class PreviewDataSource: NSObject, QLPreviewControllerDataSource { 
   
       var document: Document? 
   
       func numberOfPreviewItems(in controller: QLPreviewController) -> Int { 
        return document != nil ? 1 : 0 
       } 
   
       func previewController(_ controller: QLPreviewController, previewItemAt index: Int) -> QLPreviewItem { 
        return document! 
       } 
   } 
   
   class ProgressLoadingViewController: UIViewController { 
   
       var session: URLSession = URLSession(configuration: URLSessionConfiguration.default) 
       var downloadTask: URLSessionDownloadTask? 
   
       var dataSource: PreviewDataSource? 
   
       override func viewDidLoad() { 
        super.viewDidLoad() 
        startDownload() 
       } 
   
       func startDownload() { 
        // start progres spinner 
        downloadTask = session.downloadTask(with: URL(string: "http://che.org.il/wp-content/uploads/2016/12/pdf-sample.pdf")!) { [weak self] (downloadLocation, response, error) in 
         guard // check if download went correctly 
          error != nil, 
          let filename = response?.suggestedFilename, 
          let downloadLocation = downloadLocation 
          else { 
           print("Something went wrong: \(error!)") 
           return 
         } 
   
         // copy file 
         let fileManager = FileManager.default 
         let targetPath = URL(fileURLWithPath: filename, relativeTo: fileManager.temporaryDirectory) 
         do { 
          try fileManager.copyItem(at: downloadLocation, to: targetPath) 
         } catch let fileError { 
          print("Copying failed: \(fileError)") 
          return 
         } 
   
         // prepare preview 
         let document = Document() 
         document.previewItemURL = targetPath 
         self?.dataSource? = PreviewDataSource() 
         self?.dataSource?.document = document 
   
         let qlViewController = QLPreviewController() 
         qlViewController.dataSource = self?.dataSource 
   
         // hide progress spinner 
         self?.present(qlViewController, animated: true) { 
          self?.downloadTask = nil 
          qlViewController.reloadData() 
         } 
        } 
        downloadTask?.resume() 
       } 
   } 
   

当然这漫长完成函数应该分成几个，然后搬到了自己的类DocumentDownloadManager。