swift - url 到 pdf 返回 nil 值

Question

example filepath -> file:///Users/name/Library/Developer/CoreSimulator/Devices/4508EE28-CEC9-4AF4-9845-A76B14966A0B/data/Containers/Data/Application/AEE5DA5B-FE71-48C1-A989-8F43939002B7/Documents/folderpath/CompanyNoticeBoard/pdfs/new.pdf



 let urls = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
 let documentDirectoryURL = urls[urls.count - 1] as URL
 let dbDirectoryURL = documentDirectoryURL.appendingPathComponent("folderpath/CompanyNoticeBoard/pdfs/\(name).pdf").absoluteString

 let pdfUrl = URL(fileURLWithPath:dbDirectoryURL)

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

当我尝试将此 URL 转换为 PDFdocument 它总是返回一个 nil 值，文档变得 nil