将图像以CKAsset的形式存储在CloudKit中，图像上下颠倒 [英] Storing images in CloudKit as CKAsset, image upside-down

问题描述

我正在开发一个使用CloudKit存储和检索图像文件作为CKAsset对象的应用程序.通常，这很好用，我喜欢CloudKit的小学习曲线.但是，我会定期遇到一个特殊的问题，即图像完全颠倒存储，或者存储在左侧或右侧90º.这是一个图像存储不正确的示例:

I am working on developing an app that uses CloudKit to store and retrieve image files as CKAsset objects. Normally, this works great and I love CloudKit's small learning curve. Periodically though, I have this peculiar issue where an image is being stored either totally upside-down, or 90º to the left or to the right. Here is an example of an image that was stored improperly:

我用iPhone 5s纵向拍摄了这张照片(我没有将原始图像保存到设备中，因为我只打算将其保存在云中，否则我也将原始图像发布到这里. (因为它是MacBook Pro坐在桌子上的缘故)，您可以找出图片的原始预期方向).无论如何，我不仅从相机中获取新鲜的图像，而且从我的照片库中选择图像，也遇到了这个问题.

I took that picture with my iPhone 5s, in portrait orientation (I didn't save the original image to my device, as I only intended to save it in the cloud or else I'd post the original here too. I figured since it's a MacBook Pro sitting at a table you could figure out the original intended orientation of the picture). Anyways, I have this problem not only with images fresh from the camera, but also with an image chosen from my photo library.

这是我用来通过CloudKit存储图像的代码:

Here is the code I use to store the image via CloudKit:

let newRecord:CKRecord = CKRecord(recordType: "ImageProject")
let imageData:NSData = UIImagePNGRepresentation(game.referenceImage)!
let path = self.documentsDirectoryPath.stringByAppendingPathComponent(self.imageDirectoryName)
imageURL = NSURL(fileURLWithPath: path)
imageData.writeToURL(imageURL, atomically: true)
UIImagePNGRepresentation(game.referenceImage)!.writeToFile(path, atomically: true)
let imageFile:CKAsset?  = CKAsset(fileURL: NSURL(fileURLWithPath: path))

newRecord.setValue(imageFile, forKey: "referenceImage")

    // Save the record into the public database
    if let database = self.publicDatabase {

      database.saveRecord(newRecord, completionHandler: { (record:CKRecord?, error:NSError?) in

            // Check if there was an error
            if error != nil {
                NSLog((error?.localizedDescription)!)
            }
            else {
                // There wasn't an error
                dispatch_async(dispatch_get_main_queue()) {

                        if let savedRecord = record {
                            print("Image Successfully Saved")
                        }
                }
            }
        })
      }

在这里，game只是我创建的称为SavedGame的NSObject，它仅存储变量，在这种情况下，专门将referenceImage作为UIImage.我很确定我的检索过程不是问题，因为我注意到当我进入CK仪表板并在存储图像后下载图像时，它也会在那里旋转.以防万一，这是我用来检索图像的代码:

Here the game is just an NSObject I have created called SavedGame, that just stores variables, specifically for this case the referenceImage as a UIImage. I'm pretty sure that my retrieval process is not the issue, because I noticed when I go to the CK Dashboard and download the image after it's been stored, it's rotated there as well. Just in case, here is the code I use to retrieve the image:

// Initialize the database and start the query
..........
for record in returnedRecords {
    if let retrievedImage = record.objectForKey("referenceImage") as! CKAsset? {
         let newGame:SavedGame = SavedGame()                  
         if let data = NSData(contentsOfURL: retrievedImage.fileURL) {
              newGame.referenceImage =  UIImage(data: data)!
         }
     }
}

有人可以给我一些有关我可能在哪里犯错误的指导吗?这个问题根本不一致，这很奇怪.我估计大约有5-10％的时间会发生这种情况.我不知道这是CK问题还是我的代码有问题.任何帮助将不胜感激.预先感谢！

Could anybody give me some sort of guidance as to where I might be making a mistake? This problem is not consistent at all, it's very strange. I would estimate it happens maybe 5-10% of the time. I don't know if its a CK issue, or a problem with my code. Any help would be greatly appreciated. Thanks in advance!

推荐答案

此代码对png文件适用于我.我是从 SO问题.它被张贴在讨论的后面，所以我在这里复制它.

This code works for me for png files. I got this from this SO question. It's posted way down the discussion so I'm reproducing it here.

extension UIImage {
    func fixOrientation() -> UIImage {
        if self.imageOrientation == UIImageOrientation.up {
            return self
        }
        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
        self.draw(in: CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height))
        if let normalizedImage: UIImage = UIGraphicsGetImageFromCurrentImageContext() {
            UIGraphicsEndImageContext()
            return normalizedImage
        } else {
            return self
        }
    }
}

用法:

let cameraImage = //image captured from camera
let orientationFixedImage = cameraImage.fixOrientation()

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