PROSAGA码农传奇-swift/objective-C-无法在swift 4 iOS中的文档目录中获取正确的firebase映像

<div class =“post-text”itemprop =“text”>
  <P>
    请尝试使用以下代码
  </p>
   <pre>
    <code>
       Save Data

let placeholderURL: URL =
 getDocumentDirectoryPath()!.appendingPathComponent("\(imageName.JPG)/",
 isDirectory: true)
 let fileExists: Bool = FileManager.default.fileExists(atPath: placeholderURL.path )

if !fileExists {

let thumbnailImageURL = URL(string: firebaseURL)
             var placeholderData: Data? = nil
             if let url = url {
                 do {

placeholderData = try Data(contentsOf: (thumbnailImageURL ?? nil)!)
                 } catch {
                     print("Unable to load data: \(error)")
                 }
             }
             if urlData != nil {
                 do {
                     //saving is done on main thread
                     try placeholderData?.write(to: URL(fileURLWithPath: placeholderURL.path) , options: .atomic)
                 } catch {
                     print(error)
                 }

}
       }

</code>
  </pre>
  <P>
    回到图像
  </p>
   <pre>
    <code>
          let thumbnailURL: URL = getDocumentDirectoryPath()!.appendingPathComponent("\("imageName.JPG")/", isDirectory: true)

let fileExists: Bool = FileManager.default.fileExists(atPath: thumbnailURL.path)

var urlThumbnail:URL? = nil
    if fileExists {

urlThumbnail = URL(fileURLWithPath: thumbnailURL.path)
    } else {

urlThumbnail = URL(string: firebaseURL)
    }

</code>
  </pre>
  <P>
    图像视图中的静止图像
  </p>
   <pre>
    <code>
      self.imgtemp.sd_setImage(with: urlThumbnail, placeholderImage: UIImage(named: "placeholder.png"))

</code>
  </pre>
</DIV>