我正在尝试添加一个图像上传功能到我的iOS应用程序。我有一个函数selectPicture（），当用户点击上传按钮时会调用该函数，然后弹出一个警报，允许用户在相机和库之间进行选择。

func selectPicture() {
    let imagePicker = UIImagePickerController()
    imagePicker.delegate = self
    let alertController = UIAlertController(title: "Image Source", message: "Please choose your image source", preferredStyle: UIAlertControllerStyle.alert)
    let camera_action = UIAlertAction(title: "Camera", style: UIAlertActionStyle.default) {
        (_: UIAlertAction) -> Void in
        if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.camera) {
            print ("Camera Selected")
            imagePicker.sourceType = UIImagePickerControllerSourceType.camera
            imagePicker.allowsEditing = true
            imagePicker.modalTransitionStyle = UIModalTransitionStyle.coverVertical
            self.present(imagePicker, animated: true, completion: nil)
        }
    }
    let photoLibrary_action = UIAlertAction(title: "Photo Library", style: UIAlertActionStyle.default) {
        (_: UIAlertAction) -> Void in
        if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.photoLibrary) {
            print ("Photo Library Selected")
            
            imagePicker.sourceType = UIImagePickerControllerSourceType.photoLibrary
            imagePicker.allowsEditing = true
            imagePicker.navigationBar.titleTextAttributes = self.navbarAttributes
            imagePicker.navigationBar.tintColor = UIColor.white
            imagePicker.navigationBar.isTranslucent = false
            imagePicker.navigationBar.barTintColor = PING_ORANGE
            imagePicker.navigationController?.title = "Pick Image"
            imagePicker.modalTransitionStyle = UIModalTransitionStyle.coverVertical
            self.present(imagePicker, animated: true, completion: nil)
        }
    }
    let cancel_action = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.default) {
        (_: UIAlertAction) -> Void in
        print ("Cancel Selected")
    }
    alertController.addAction(camera_action)
    alertController.addAction(photoLibrary_action)
    alertController.addAction(cancel_action)
    self.present(alertController, animated: true, completion: nil)
    
}

到目前为止，一切都很正常，但是当我选择一个图像时，委托方法没有被调用。

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any], editingInfo: [AnyHashable: Any]!) {
    let image = info[UIImagePickerControllerOriginalImage] as? UIImage
    print("Image Print")
    print(image)
    if image != nil {
        print ("INSIDE IMAGE DID FINISH PICKING")
        dismiss(animated: false) {
            self.uploadProfileImage(image: image!)
        }
        
    } else {
        dismiss(animated: false) {
            
        }
    }
}

我刚开始使用swift，所以我可能漏掉了一些东西。有人能帮我吗？
谢谢你。