在 Swift 3/4 中获取 EXIF 信息时出错

Question

我想从 PhotoLibrary 中的图像中获取 EXIF 数据，但找不到正确的方法。我使用了来自this question 和this one 的答案。我得到以下控制台输出：

imageSource:  <UIImage: 0x6080000b8a20> size {3000, 2002} orientation 0 scale 1.000000
2017-09-18 11:24:28.513567+0300 PhotoTest[10581:6526935] CGImageSourceCopyPropertiesAtIndex:3517: *** ERROR: CGImageSourceCopyPropertiesAtIndex: source is not a CGImageSourceRef
2017-09-18 11:24:29.071412+0300 PhotoTest[10581:6527417] [discovery] errors encountered while discovering extensions: Error Domain=PlugInKit Code=13 "query cancelled" UserInfo={NSLocalizedDescription=query cancelled}

这是我当前的代码尝试。我会很感激任何解决方案或想法。我一直在摸索各种方法，但我对imageIO的了解还不够，无法解决问题。

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
    self.dismiss(animated: true, completion: nil)

    let bigImage = info[UIImagePickerControllerOriginalImage] as? UIImage
    photoImageView.image = bigImage

     imageData = UIImagePNGRepresentation(bigImage!) as NSData?


    if let imageSource = info[UIImagePickerControllerOriginalImage] {
         print("imageSource: ", imageSource)

        let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource as! CGImageSource, 0, nil)


         //print("imageProperties: ", imageProperties!)
        if let dict = imageProperties as? [String: Any] {
            print(dict)
        }
    }

    dismiss(animated: true, completion: nil)
}

Answer 1

你看到的是：

*** ERROR: CGImageSourceCopyPropertiesAtIndex: source is not a CGImageSourceRef

行，因为您需要通过 CGImageSourceCreate... API 之一创建您的 imageSource。

尝试这样做：

    if let bigImage = info[UIImagePickerControllerOriginalImage] as? UIImage
    {
        if let imageData = UIImagePNGRepresentation(bigImage)
        {
            if let imageSource = CGImageSourceCreateWithData(imageData as CFData, nil)
            {
                print("imageSource: ", imageSource)

                let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil)

                //print("imageProperties: ", imageProperties!)
                if let dict = imageProperties as? [String: Any] {
                    print(dict)
                }
            }
        }
    }

Answer 2

我找到了一个不同的解决方案，如下：

import Photos 
import PhotosUI

 func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {

        let assetURL = info[UIImagePickerControllerReferenceURL] as! NSURL
        let asset = PHAsset.fetchAssets(withALAssetURLs: [assetURL as URL], options: nil)
        guard let result = asset.firstObject else {
            return
        }

        let imageManager = PHImageManager.default()
        imageManager.requestImageData(for: result , options: nil, resultHandler:{
            (data, responseString, imageOriet, info) -> Void in
            let imageData: NSData = data! as NSData
            if let imageSource = CGImageSourceCreateWithData(imageData, nil) {
                let imageProperties2 = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil)! as NSDictionary
                print("imageProperties2: ", imageProperties2)
            }

        })
        dismiss(animated: true, completion: nil)
    }

希望这对其他人有所帮助。

Answer 3

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    if let exifData = info[.mediaMetadata] as? [String: Any] {
        //print(exifData)
    }
}