PDFView不显示我的PDF [英] PDFView does not display my PDF

问题描述

我无法获取pdfView来显示URL中的PDF.我可以获取文件，并且根据控制台它确实存在.这是我所做的:

I am having trouble getting my pdfView to display a PDF from a URL. I can get the file, and it definitely exists according to the console. Here's what I've done:

首先，我声明一个文档选择器:

First, I declare a document picker:

 @IBAction func addFromICloud(_ sender: UIBarButtonItem) {

    let documentPicker = UIDocumentPickerViewController(documentTypes: ["public.composite-content"], in: .import)
    documentPicker.delegate = self
    documentPicker.modalPresentationStyle = UIModalPresentationStyle.formSheet
    present(documentPicker, animated: true, completion: nil)

}

第二，我从DocumentPickerViewController获取URL和文档名称:

Second, I get a URL and the name of the document from DocumentPickerViewController:

func documentPicker(_ controller: UIDocumentPickerViewController,
                    didPickDocumentAt url: URL) {
    print ("Picker's url is \(url)")
    theName = String(describing:url.lastPathComponent)
    books.append(theName)
    tableView.reloadData()
}

然后，我将TheName附加到文档目录路径:

Then, I append theName to the document directory path:

fileIsFromService = true
indexPoint = indexPath.row
let DocumentDirectory = try! FileManager.default.url(for:  .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
docURL = DocumentDirectory.appendingPathComponent(theName)

然后，我确保该文件存在，并且确实存在:

Then I make sure that the file exists, and it does:

let fileExists = FileManager().fileExists(atPath: (finalDocURL?.path)!)
print ("The value of fileExists is \(fileExists)")
addressArray.append(docURL!)
print ("The url to be passed should be \(docURL!)")
print ("addressArray is now \(addressArray)")
indexPoint = indexPath.row
viewController.load(books[indexPath.row])

然后，在viewController中，我尝试使用docURL加载pdfView:

Then, in viewController, I try to load the pdfView with docURL:

func load(_ name: String) {
    if fileIsFromService == true {
        guard let path = docURL else {return}

        if let document = PDFDocument(url: path){
            pdfView.document = document
        }

        pdfView.goToFirstPage(nil)

        if UIDevice.current.userInterfaceIdiom == .pad {
            title = name
        }
    }

我没有任何错误，只是空白的pdfView.我知道已经添加了pdfView的子视图.没有变量为零.我怀疑我需要从docURL中获取数据，但是我应该在哪里写呢?

I get no errors, just a blank pdfView. I know that the pdfView's subview has been added. No variables are nil. I suspect that I need to get the data out of docURL, but where would I write it?

推荐答案

问题是您要导入的pdf只是一个临时文件.您需要将临时文件url复制/移动到您的应用程序文档文件夹中.

The problem is that the pdf you are importing it is just a temporary file. You need to copy/move the temporary file url to your app documents folder.

UIDocumentPickerModeImport URL指向所选对象的副本 文档.该文档是一个临时文件.它仍然仅可用 直到您的应用程序终止.要保留永久副本，您必须 将此文件移到沙箱中的永久位置.

UIDocumentPickerModeImport The URL refers to a copy of the selected document. This document is a temporary file. It remains available only until your application terminates. To keep a permanent copy, you must move this file to a permanent location inside your sandbox.

func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentAt url: URL) {
    let documentDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
    do {
        try FileManager.default.moveItem(at: url.standardizedFileURL, to: documentDirectory.appendingPathComponent(url.lastPathComponent))
        tableView.reloadData()
    } catch {
        print(error)
    }
}

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