Ios Swift mapview无法显示缩略图图像

我正在将图像写入一个文件并在mapview didSelect方法中读取，它给出了图像数据读取错误

 var localImageFileUrl: URL? = nil

            do {
                delegate.documentDirectoryUrl = try FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)

                if let data = aStruct.imageData  {
                    localImageFileUrl =  delegate.documentDirectoryUrl!.appendingPathComponent("Image.png")
                    UserDefaults.standard.set(localImageFileUrl, forKey: "localImageFileUrl")
                    try data.write(to: localImageFileUrl!)
                }

            }
            catch {
                print("error")
            }

在这里测试，效果很好

          do{
                 print("imageUrl0: \(localImageFileUrl)")
                let imageData: Data = try Data(contentsOf: localImageFileUrl as! URL)
                let image = UIImage(data: imageData)
               print(image)
            }catch{
                print("Unable to load image data: \(error)")
            }

调试窗口输出：

imageUrl0： 可选的(file:///var/mobile/Containers/Data/Application/19A5A226-3CAF-4DC0-9015-40278703C5BA/Documents/Image.png)

可选（，{120，120}） 很好

          do{
                 print("imageUrl0: \(localImageFileUrl)")
                let imageData: Data = try Data(contentsOf: localImageFileUrl as! URL)
                let image = UIImage(data: imageData)
               print(image)
            }catch{
                print("Unable to load image data: \(error)")
            }

我通过如下结构传递数据：

   let endPtPin = GpsData.MyEndPt(latitude:  Double(latitudeStr) as! Double, longitude: Double(longitudeStr) as! Double, url: localImageFileUrl! as NSURL)

在mapview didSelect方法中，我提取url，并尝试访问图像，但它给出错误：

 func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {

     DispatchQueue.main.async {
        if let thumbnailImageButton = view.leftCalloutAccessoryView as? UIButton,
        let url = (view.annotation as? GpsData.MyEndPt)?.thumbnailUrl
         {
            print("imageUrl: \(url)")
            do{
                let imageData: Data = try Data(contentsOf: url as URL)
                let image = UIImage(data: imageData)
                    thumbnailImageButton.setImage(image, for: UIControlState.normal)

            }catch{
                print("Unable to load image data: \(error)")
            }
        }
    }
}

调试窗口显示错误：

 func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {

     DispatchQueue.main.async {
        if let thumbnailImageButton = view.leftCalloutAccessoryView as? UIButton,
        let url = (view.annotation as? GpsData.MyEndPt)?.thumbnailUrl
         {
            print("imageUrl: \(url)")
            do{
                let imageData: Data = try Data(contentsOf: url as URL)
                let image = UIImage(data: imageData)
                    thumbnailImageButton.setImage(image, for: UIControlState.normal)

            }catch{
                print("Unable to load image data: \(error)")
            }
        }
    }
}

图像URL： 可选的(file:///var/mobile/Containers/Data/Application/19A5A226-3CAF-4DC0-9015-40278703C5BA/Documents/Image.png) 2020-03-27 00:07:04.079576-0500 r2nr[9945:4518812]NSURL连接 已完成，错误代码为1002

2020-03-27 00:07:07.009134-0500 r2nr[9945:4518751] cfurlCopyResourcePropertyWorkey失败，因为它被传递了一个URL 没有计划

无法加载图像数据：错误域=NSCOCAERRORDOMAIN代码=256 无法打开文件“Image.png” UserInfo={NSURL=可选(file:///var/mobile/Containers/Data/Application/19A5A226-3CAF-4DC0-9015-40278703C5BA/Documents/Image.png)}

---

文件路径未更改，但无法从文件中读取图像数据。怎么了？

我花了几个小时，找到了解决办法。 我正在访问图像数据作为数据

if let data = aStruct.imageData  {
      localImageFileUrl =  delegate.documentDirectoryUrl!.appendingPathComponent("Image.png")
      UserDefaults.standard.set(localImageFileUrl, forKey: "localImageFileUrl")
      try data.write(to: localImageFileUrl!)
 }

我将数据转换为PNG格式，如下所示，效果良好：

  do {
        delegate.documentDirectoryUrl = try FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
       let image = UIImage(data: aContactStruct.imageData!)

       if let data = UIImagePNGRepresentation(image!){{
             localImageFileUrl =  delegate.documentDirectoryUrl!.appendingPathComponent("Image.png")
              UserDefaults.standard.set(localImageFileUrl, forKey: "localImageFileUrl")
              try data.write(to: localImageFileUrl!)
       }

   }
   catch {
            print("error")
   }