复制使用UiimagePicker选择的照片和元数据，并带有修改的Exif Metadata的新照片

Question

我希望能够使用 UIImagePicker 从照片库中选择一张照片，并将所有图像（带有修改后的 Exif 元数据）复制到我保存在“照片”中的新照片中。如果我使用 UIActivityViewController 选择保存选项（从复制/保存/分配到联系人/打印/添加到共享相册/保存到文件），则当我从加载的图像数据创建新的 UIimage 时，不会传输输入图像元数据修改后的元数据。如何获取附加到已保存照片的修改过的元数据的图像？

Answer 1

最终找到了如何做到这一点。图像选择器之后执行的代码如下。重要的是创建从 URL 提取元数据的源，而不是从 image.jpegData 的数据中提取元数据。 jpegData 选项仅包含 JPEG 操作必需的元数据

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

     let info = convertFromUIImagePickerControllerInfoKeyDictionary(info)

    if let image = info[convertFromUIImagePickerControllerInfoKey(UIImagePickerController.InfoKey.originalImage)] as? UIImage {

        let url  = info[UIImagePickerController.InfoKey.imageURL.rawValue]
       
        let source = CGImageSourceCreateWithURL(url as! CFURL, nil)
      
        let metadata = CGImageSourceCopyPropertiesAtIndex(source!,0,nil) as? [AnyHashable: Any]
        var metadataAsMutable = metadata
        //let ImagePropertyExifDictionary = kCGImagePropertyExifDictionary
        
        guard var exif = metadataAsMutable![kCGImagePropertyExifDictionary] as? [String:Any] else {return}
        if((exif[kCGImagePropertyExifUserComment as String] == nil))
        {
        exif[kCGImagePropertyExifUserComment as String] = "Test User Comment"
        }
        metadataAsMutable![kCGImagePropertyExifDictionary] = exif as CFDictionary
        
       ImagePickerView.contentMode = .scaleAspectFit

        let image2 = image.imageWithInsets(insets: UIEdgeInsets.init(top: 0,left: 0,bottom: 300,right: 0))
        let data1 = image2!.jpegData(compressionQuality: 1.0)
        newData = addImageProperties(imageData: data1!, properties: metadataAsMutable! as CFDictionary)
        image3 = UIImage(data:newData)!
        
        ImagePickerView.image = image3

        captionButton.isEnabled = true; saveButton.isEnabled = true;
        
    }else {
        print("Error")
    }
    self.dismiss(animated: true, completion: nil)

}

func addImageProperties(imageData: Data, properties: NSMutableDictionary) -> Data? {
  
 if let source = CGImageSourceCreateWithData(imageData as CFData, nil) {
  if let uti = CGImageSourceGetType(source) {
      let destinationData = NSMutableData()
      if let destination = CGImageDestinationCreateWithData(destinationData, uti, 1, nil) {
      CGImageDestinationAddImageFromSource(destination, source, 0, properties)
      if CGImageDestinationFinalize(destination) == false {
      return nil
    }                    
    return destinationData as Data
  }
}

}
返回零
获取newData

后，保存按钮IBAction为，

@IBAction func shareAction(_ sender: Any) {
        self.saveImageDataAsImage(newData)
 }

将图片保存到与所选图片同一个相册的函数为

 func saveImageDataAsImage(_ data: Data) {
    var newImageIdentifier: String!

    PHPhotoLibrary.shared().performChanges{
        //if #available(iOS 9.0, *) {
            let assetRequest = PHAssetCreationRequest.forAsset()
            assetRequest.addResource(with: .photo, data: data, options: nil)
            newImageIdentifier = assetRequest.placeholderForCreatedAsset!.localIdentifier
//            } else {
//                // Fallback on earlier versions
//            }
    } completionHandler: { (success, error) in
        DispatchQueue.main.async(execute: {
            if success, let newAsset = PHAsset.fetchAssets(withLocalIdentifiers: [newImageIdentifier], options: nil).firstObject {
                // ...
            } else {
                // ...
            }
        })

    }
}