ios – 无法编辑屏幕截图,performChanges阻止失败

我正在开发一个允许用户使用PhotoKit编辑照片的应用程序.我之前将编辑过的照片以JPEG格式保存到磁盘.我想避免转换为JPEG,并已实施修改,以便这样做.它适用于使用相机拍摄的照片,但如果您尝试编辑屏幕截图,PHPhotoLibrary.sharedPhotoLibrary().performChanges块将失败并记录操作无法完成. (可可错误-1.).我不确定为什么这会导致performChanges块失败,我在这里做错了什么？

我创建了一个演示问题的sample app available to download,我在下面列出了相关代码.该应用会尝试编辑照片库中的最新照片.如果成功,它将提示访问以编辑照片,否则不会发生任何事情,您将看到控制台日志.要重现此问题,请截取屏幕截图然后运行该应用.

当前使用屏幕截图的代码：

let jpegData: NSData = outputPhoto.jpegRepresentationWithCompressionQuality(0.9)

let contentEditingOutput = PHContentEditingOutput(contentEditingInput: self.input)

var error: NSError?
let success = jpegData.writetoURL(contentEditingOutput.renderedContentURL,options: NSDataWritingOptions.AtomicWrite,error: &error)
if success {
    return contentEditingOutput
} else {
    return nil
}

导致屏幕截图失败的替换代码：

let url = self.input.fullSizeImageURL
let orientation = self.input.fullSizeImageOrientation
var inputimage = CIImage(contentsOfURL: url)
inputimage = inputimage.imageByApplyingOrientation(orientation)

let outputPhoto = createOutputimageFromInputimage(inputimage)!

let originalImageData = NSData(contentsOfURL: self.input.fullSizeImageURL)!
let imageSource = CGImageSourceCreateWithData(originalImageData,nil)

let dataRef = CFDataCreateMutable(nil,0)
let destination = CGImageDestinationCreateWithData(dataRef,CGImageSourceGetType(imageSource),1,nil) //getType automatically selects JPG,PNG,etc based on original format

struct ContextStruct {
    static var ciContext: CIContext? = nil
}
if ContextStruct.ciContext == nil {
    let eaglContext = EAGLContext(API: .OpenGLES2)
    ContextStruct.ciContext = CIContext(EAGLContext: eaglContext)
}

let cgImage = ContextStruct.ciContext!.createCGImage(outputPhoto,fromrect: outputPhoto.extent())

CGImageDestinationAddImage(destination,cgImage,nil)

if CGImageDestinationFinalize(destination) {
     let contentEditingOutput = PHContentEditingOutput(contentEditingInput: self.input)

     var error: NSError?
     let imageData: NSData = dataRef
     let success = imageData.writetoURL(contentEditingOutput.renderedContentURL,options: .AtomicWrite,error: &error)
     if success {
          //it does succeed
          return contentEditingOutput
     } else {
          return nil
     }
}