如何在我的IOS应用程序中使用iOS 9.2照片编辑器

Question

我希望在我的应用程序中使用Swift语言创建iOS 9.2等照片编辑器，经过多次搜索后我才找到照片编辑扩展名，但是当我调用startContentEditingWithInput时，方法没有任何反应。

我想要这样的编辑：

import UIKit
import Photos
import PhotosUI
class PhotoEditingViewController: UIViewController, PHContentEditingController {

var input: PHContentEditingInput?

override func viewDidLoad() {
    super.viewDidLoad()

    let img = UIImage(named: "content_item.png")
    let phei = PHContentEditingInput
    startContentEditingWithInput(phei ,img)
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

// MARK: - PHContentEditingController

func canHandleAdjustmentData(adjustmentData: PHAdjustmentData?) -> Bool {
    // Inspect the adjustmentData to determine whether your extension can work with past edits.
    // (Typically, you use its formatIdentifier and formatVersion properties to do this.)
    return false
}

func startContentEditingWithInput(contentEditingInput: PHContentEditingInput?, placeholderImage: UIImage) {
    // Present content for editing, and keep the contentEditingInput for use when closing the edit session.
    // If you returned true from canHandleAdjustmentData:, contentEditingInput has the original image and adjustment data.
    // If you returned false, the contentEditingInput has past edits "baked in".
    input = contentEditingInput

}

func finishContentEditingWithCompletionHandler(completionHandler: ((PHContentEditingOutput!) -> Void)!) {
    // Update UI to reflect that editing has finished and output is being rendered.

    // Render and provide output on a background queue.
    dispatch_async(dispatch_get_global_queue(CLong(DISPATCH_QUEUE_PRIORITY_DEFAULT), 0)) {
        // Create editing output from the editing input.
        let output = PHContentEditingOutput(contentEditingInput: self.input!)

        // Provide new adjustments and render output to given location.
        // output.adjustmentData = <#new adjustment data#>
        // let renderedJPEGData = <#output JPEG#>
        // renderedJPEGData.writeToURL(output.renderedContentURL, atomically: true)

        // Call completion handler to commit edit to Photos.
        completionHandler?(output)

        // Clean up temporary files, etc.
    }
}

var shouldShowCancelConfirmation: Bool {
    // Determines whether a confirmation to discard changes should be shown to the user on cancel.
    // (Typically, this should be "true" if there are any unsaved changes.)
    return false
}

func cancelContentEditing() {
    // Clean up temporary files, etc.
    // May be called after finishContentEditingWithCompletionHandler: while you prepare output.
}

}